Keywords: maximum shear XRD, X-ray diffraction Lat., Latitude Long Global Positioning System CAIP, Central Africa Intra plate

The aim of my thesis is: 1) to study of the main active and tsunamigenic zones in the Eastern Mediterranean and northern Egypt. The characterization of active faults has been identified from the Red Sea area in the east to Salloum in the west. Historical and instrumental data are used to determine the seismic activity of the faults. I also compile the geology and active faults, seismicity, focal mechanisms, and proceed with stress tensor inversions that help to 1) identify the present day stress field in northern Egypt and adjacent Mediterranean regions 2) to analyze the stratigraphy of tsunami deposits through trenching and coring in two selected sites; EL Alamein and Kefr Saber. Trenches and cores investigations enable us tocorrelate the paleotsunami deposits with the sequences of historical tsunamis documented in the historical seismicity catalogue; and 3) to model maximum wave height and travel times to the Egyptian coast from the worst case scenariosfrom the main seismic zones of the Eastern and Western Hellenic arc. This help in estimating the wave height and travel times as away for seismic hazard and risk assessment, and mitigate its effects in northern Egypt. My thesis includes six chapters. The main items of these chapters are summarized as follows: -Chapter I Introduction: This chapter introduces the steps and objectives of my study and the previous international methodology used in the active tectonics and paleo tsunamis studies all over the world in the last 20 years. The paleotsunami studies help in the identification of tsunami deposits thousands of years in the world. This chapter also includes the methodology used to study the seismotectoniccharacteristics and paleotsunami deposits. It also discusses the importance of this study in northern Egypt as the north of Egypt includes ancient Egyptian cultural heritage (i.e.Pharaohs archaeological sites) and the development of National strategic projects; in addition of the construction of new cities along the Egyptian coast. This chapter continues describing the basis of tsunami modelling to estimate the wave height and the travel time to the northern coast of Egypt and far-field effects from seismic sources of the Eastern and Western Hellenic arcs. Chapter II Methodology: This chapter introduces the work methodologies. The methodology is classified into three stages. The first stage is a concern with seismotectonic, focal mechanisms and their parameters and the stress tensor inversion and its definition. The

FOREWORD

First, I would like to convey my sincere thanks to my thesis supervisor, Prof. Dr Mustapha Meghraoui and my adviser Dr. Mohamed El Gabry, whose advice and mentorship have been tireless, fair and of top-notch standards. I am grateful to my Prof. Dr Mustapha for teaching me the methodologies, problem-solving approaches, and sharing his experiences in active tectonics and his knowledge during the stages of my works, Dr Mohamed El Gabry, for his cooperation's and his continued assistance during my field work and PhD stages. Last but not the least, my sincerest gratitude goes to my family; my father Mostafa, my mother Jehan and my wife Amal, who give me a deep support through all situations in my life to help me in my work progress.

September 2017

Asem SALAMA

List of Figures Pages

Fig. 1: Seismic activity and tectonic map based on geological map of Libya (1985) geological map of Egypt EMRA (2008), Bathworth 2008, and seismicity data for north Egypt of NRIAG bulletin from 1997-2016 and the seismicity data of the Eastern Mediterranean from IRIS bulletin.

Fig. 2: Bartington MS-2 Magnetic Susceptibility measurements.

Fig. 3: Collected samples in this study of 25 grams for grain size and X-ray diffraction and totally organic and inorganic measurements Fig. 4: Photos of the collected samples from cores and trenches in the studied area.

Fig. 5: Philips PW 1730 X-ray diffractometer used in the study.

Fig. 6: Photo of plant remains that were dated in our study in Beta Analytical laboratory.

Fig. 7: Summary of the distribution of focal mechanisms for earthquakes along the Hellenic trench constructed based on [START_REF] Cavazza | The TRANSMED Atlas. The Mediterranean region from crust to mantle geological and geophysical framework[END_REF][START_REF] Billi | Recent tectonic reorganization of the Nubia-Eurasia convergent boundary heading for the closure of the western Mediterranean[END_REF][START_REF] Benetatos | Focal mechanisms of shallow and intermediate depth earthquakes along the[END_REF]; (see reference Table 14,15 of focal mechanism data in Appendix A). Fig. 12: Tectonic geological map of Cairo Suez zone compiled structures elements after [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF]geology map EMRA, 2008) using ArcGIS map version 10.2 Software. ix Fig. 13: Tectonic geological map of Nile Delta based on compiled structures by [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF], geologic map EMRA, 2008) using ArcGIS map version 10. 2. Fig. 14: (a) Generalized tectonic settings of the Aqaba by Hertman (2014). The Evrona and Timna basins are mapped from bathymetric, gravimetric and magnetic data Frieslander, (2000); ten [START_REF] Brink | Magnetic character of a large continental transform: An aeromagnetic survey of the Dead Sea Fault[END_REF]. (b) Schematic models of the deep section of the basins Ben [START_REF] Ben-Avraham | Structural framework of the gulf of Elat (Aqaba), northern Red Sea[END_REF] and ten [START_REF] Brink | Anatomy of the Dead Sea Transform; does it reflect continuous changes in plate motion?[END_REF]). 2 and4 in Appendix A). 5 and6 in Appendix A). Fig. 32: Stress map of the North Egypt and Eastern Mediterranean region (this map is constructed based on data from the calculated stress inversion in this study, tensor and world stress data (http://www.world-stress-map.org/), Egyptian geological map (EMRA, 2008), Reilinger et al. 2006, Saleh and[START_REF] Saleh | New constraints on the Nubia-Sinai-Dead Sea fault crustal motion[END_REF]. Fig. 34: The location and Geomorphology land forms map in the studied area by [START_REF] Raslan | Geomorpholiogical and hydrogeological studies on some localities along the Northwestern Coast of Egypt[END_REF]. Fig. 51: Description of core no.1 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 166 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 3) and organic matter are interpreted as deposits of tsunami origin. Fig. 52: Description of core no.1 section 2 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The fourth layer (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility and organic matter are interpreted as deposits of tsunami origin. Fig. 53: Description of core no.2 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at s ~90 cm deep located south of core 1 at ~264 m from the shoreline. It reveals 2 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2) and organic matter are interpreted as deposits of tsunami origin. Fig. 54: Description of core no.3 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at located at 270 m far from the shoreline and the outlet of seawater. It reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2 and 3) and with laminations at 2 and high organic matter are interpreted as deposits of tsunami origin. Fig. 55 : Description of core no.4 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 435 m from the shoreline 166 m from the shoreline. It reveals 2 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 3) and organic matter are interpreted as deposits of tsunami origin. Fig. 56: Description of core no.5 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 490 m distance from the shoreline and the sedimentary succession does not show any possible sedimentary heigh energy sedimentaey layer of tsunami origin. Fig. 57: Description of core no.6 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 320 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2) and organic matter are interpreted as deposits of tsunami origin. Fig. 58: Description of core no.7 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 273 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2) and organic matter are interpreted as deposits of tsunami origin. Fig. 59: Description of core no.8 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 214 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1, 2 and 3) and organic matter are interpreted as deposits of tsunami origin. Fig. 60: Description of core no.9 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 130 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand with highly broken shells fragments and rich in organic matter. The high values of magnetic susceptibility and organic matter point to the white coarse sands with broken shells interpreted as tsunami deposits. Fig. 61: Description of core no.10 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 245 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1, 2 and 3) and organic matter are interpreted as deposits of tsunami origin Fig. 62: Description of core no.11 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 151 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2) and organic matter are interpreted as deposits of tsunami origin Fig. 63 : Description of core no.12 section 1 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 151 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse xiv sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1, 2 and 3) and organic matter are interpreted as deposits of tsunami origin Fig. 64: Description of core no.12 section 2 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The fourth layer (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility and organic matter are interpreted as deposits of tsunami origin Fig. 65: Composite section for the trenches in Kefr Saber.

List of Tables

Pages

Table 1: Diffraction standard main peak identify minerals according to (ICDD) Table 2: The earthquakes parameters and stress axes of the significant earthquakes in northern Egypt.

Table 3: Parameters of the present day stress tensor deduced from focal mechanisms in this study. Table 4: Historical earthquakes and tsunamis effect on the north Egyptian coast Table 5: Fault geometry and parameters (see Fig. 77) in the east Hellenic arc used for our modelling and scenario.

Table 6: Fault configuration (see Fig. 73) in the west Hellenic arc used for our modelling and scenario. zones. This method used as the Right Dihedron method and the Rotational Optimization method. The Rotational Optimization method has used in the determination of the four stress parameters, --used stress Tensor program to calculate these parameters (Delvaux and Sperner,1993). The second stage concern with Paleotsunami methodology, the main items to identify the tsunami deposits is by the tsunami signatures and the laboratories measurements include X-ray scanning , magnetic susceptibility, grain size analysis (i.e. mean size and sorting calculated according to Folk,1968 equations), sampling and macrofossil detections, XRD analysis to identify the minerals, total organic and inorganic matter measurements and carbon dating methodology and its history as effective tools for the scientists in dating. The third stage concerns with the tsunami modelling methodology. Modeling was which carried out using two worst sceneries to estimate the wave height and travel time across the Egyptian coasts. Focal mechanism solutions are for magnitude M L L the continental margin from the published data in different journals for the Egyptian territory. The inversion method of [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF] and Delvaux et al.(2010) is used for evaluating the stress field parameters in northern Egypt using the focal mechanisms of earthquakes.

The stress inversion results obtained in the northern Egypt active zones reflect an extensional stress regime with stress regime index value between 0.5 1, except for the trend B in the Egyptian continental margin zone A which shows the value 2.12 and acompressive regime index. The Tamsah and Baltim trend in the East continental margin is characterized by low seismicity data;where the stress orientation indicates N-S (Baltim trend) and NE-SW (Tamash trend) and a secondary E-W to NW-SE orientation observed from 11 petroleum wells [START_REF] Tingay | Present-day stress-field rotations associated with evaporites in the offshore Nile Delta[END_REF]. In this study, the present day stress map is xx constructed based on the calculated stresses from collected focal mechanism data and the borehole breakout data in the study area and the GPS vector velocities calculated by [START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF].

Chapter IV Paleotsunami: This chapter describes the effects of large historical tsunamis like 21 July 365, 8 August 1303, 24 June 1870 on the northern Egyptian coast and adjacent Mediterranean region coasts. The was preserved in the historical documents and recent catalogues like Ambrasey (2009) and Guidoboni (2009).

The fieldwork was carried out using trenching and coring at Kefr Saber and El Alamein sites to distinguish and recognize the stratigraphy of tsunami deposits according to their characteristics and signatures. The two selected sites were chosen according to geomorphological and geological aspects. The two selected sites are located in the northwestern part of the Mediterraneancoast and northern part of the Western Desert which is covered mainly by a thin blanket of Miocene rocks forming a vast persistent limestone plateau. It extends from the western side of the Nile valley and delta in the east to El-Salloum in the west and from the Mediterranean coastal plain in the north to the Qattara and Siwa depression in the south (El-Bastwasy, 2008). This area is affected structurally by E-W trending faults and from the east and the south with Qattara Alamein ridge and located in the north with Alamein faults NW-SE trends. The Egyptian coastlineis characterized by hummocky and rocky platforms and sand dunes along shorlines with variable heights ranging from 5 to 20 maximum. The obtained chronology and dating results with the stratigraphic succession and tsunami signatures are summarized by two composite sections in Kefr Saber and El Alamein. The Kefr Saber site shows only one white tsunami layer with reworked broken shells compared with 21 July 365 tsunami event while the El Alamein site shows four tsunami layers which are compared with 1600 BC Santorini, 21 July 365, 8

August 1303 and the recent of 24 June 1870 tsunami events.

Chapter V consists in the tsunami modelling andscenarios in the northern Egypt.In this chapterI take as an example the significant recent tsunami modelling such as the massive tsunami generated by the major East Japan Tohoku earthquake of Mw 9.0 on March11, 2011, with a maximum wave height that reached 19.5 m at Sendai Plain [START_REF] Mori | Survey of 2011 Tohoku earthquake tsunami inundation and run-up[END_REF]. In my work, two simple scenarios are constructed using the Mirone software update version 2.7.0 last modified on 22 October 2016 (Luis, 2007) using the data from thetsunami deposits of 21 July 365 and 8 August 1303 AD. Two worst scenarios are chosen to estimated wave height and travel times depending on the historical information of the source locations and fault ruptures calculated by [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF] and Pagnoni et al. (2015).

xxi

The estimated fault mechanism depends on the recent large earthquakes events in the Hellenic zone.

Our worst scenario for the Eastern Hellenic arcshow that the wave arrival time to the Egyptian coast is 33 minutes and with maximum wave height ranging from 7-10 m at Kefr Saber while for the El Alamein area shows an expected arrival time of about 50 minutes.

The Western Hellenic scenario shows much longer arrival time with amaximum wave height of 0.88 1.76 m at Kefr Saber and 0.42-0.87 m wave height at El Alamein after 100 minutes. The simulation results agree well with [START_REF] Mohammed | Impacts on Egyptian Coastal zones Eastern Mediterranean Tsunamigenic Earthquakes and their Geology[END_REF] in the estimated wave heights at Salloum, Alexandria and Domietta. However, our results show a higher estimated wave height at Matrouh and El Arish for the Eastern Hellenic arc scenario. In case of the Western Hellenic scenario, the estimated wave height coincides with Shaw et al. (2008) at Alexandria but itdiffers in the travel time arrival of the waves.

Chapter VI, this chapter is the final conclusive that show the final results obtained from seismicity, focal mechanisms, calculated stress inversion, geodetic data to identify the present day deformation and the main stress tectonic regime in the north Egypt and south eastern Mediterranean. The main result is that the whole northern Egypt is considered as a part of extensional regime except the Egyptian continental margin. Based on the paleotsunami study, the main tsunamigenic seismic sources with possible Mw > 8 in the Eastern Mediterranean region (eastern and western Hellenic arc) are taken into consideration. These arcs were considered as the the most hazaradous subduction zone and source segments of the possible future tsunamis in this region for northern Egypt. The results obtained from the trenching at Kefr Saber are correlatedwith 21 July 365 in Kefr Saber, while the four tsunami layers in cores at El Alamein site are correlated with the historical tsunami events of 1600 BC, 21 July 365, 8 August 1303, 24 June 1870. This chapter ends with the perspective for the seismotectonicsof Egypt including the study of El Alamein active Quaternary fault and more investigation of paleotsunamideposits. In this thesis, I also suggest warning messages depending on historical data, simulation data as a function of tsaunmigenic earthquake magnitudes to be provided for the decision-makers in case of tsunami hazard. A second recommendation includes the preparation of an Early warning system for tsunami hazards.

xxii Cette thèse est organisée suivant six chapitres que je résume comme suit :

Chapitre (I) Introduction: Ce chapitre présente les étapes et les objectifs de mon étude et la méthodologie internationale précédente utilisée dans les études de tectonique active et de paléotsunamis dans le monde entier au cours des 20 dernières années. Les études sur le paléo tsunami aident à identifier les dépôts de tsunamis depuis des milliers d'années dans le monde. L'identification des dépôts de tsunami par l'analyse des sédiments de surface (âge de l' Holocène) collectée à l'aide de carottages et par comparaison avec les dépôts actuels de tsunami observés ailleurs (Sicile, Algérie, Tohoku, Sumatra). La complexité de la dynamique côtière est prise en compte par l'étude des processus sédimentaires côtiers, paléoenvironnementaux et des fluctuations du niveau de la mer durant l'Holocène. En effet, l'existence de fossiles marins dans un environnement continental associé au développement d'espèces telles qu' ostracodes, diatomées, gastéropodes, plantes aquatiques peut indiquer des changements de salinité à long terme associés aux inondations soudaines du tsunami [START_REF] Kortekaas | Distinguishing tsunami and storm deposits: An example from Martinhal, SW Portugal[END_REF].

Par exemple, le long de la côte de Kiritappu au Japon, Nanayama et al. (2003) ont identifié des plaques de sable s'étendant sur 3 kilomètres à l'intérieur des terres, montrant de xxiii grands tsunamis inondés tous les 500 ans en moyenne entre 2000 et 7000 ans. De même, une étude d'un record de 7000 ans dans un lac côtier de l'Oregon (ouest des Etats-Unis), [START_REF] Kelsey | Tsunami history of an Oregon coastal lake reveals a 4600 yr record of great earth-quakes on the Cascadia subduction zone[END_REF] a identifié 12 dépôts de paléotsunami au cours des 4600 dernières années.

D'autres enregistrements de tsunamis multiples ont été étudiés au Chili (Cisternas et al., 2005). Le long de la côte sud de l'île Andaman, en Inde, Malik et ses collaborateurs (2015) ont identifié trois séismes historiques et des tsunamis transocéaniques associés au cours des 1000 dernières années, en fonction de la stratigraphie des dépôts et des datations associées.

En xxiv utilisé le programme Tensor de stress pour calculer ces paramètres (Delvaux et Sperner, 1993). L'indice du régime de contrainte (R ') est calculé numériquement avec le logiciel

Tensor pour chaque zone sismique active du nord de l'Egypte. Il est défini en fonction de l'orientation de l'ellipsoïde de contrainte selon [START_REF] Delvaux | Paleostress reconstructions and geodynamics of the Baikal region, Central Asia. Part II: Cenozoic tectonics stress and fault kinematics[END_REF]. Elle est exprimée en extension lorsque l est verticale, en décrochement lorsque 2 est verticale et en compression lorsque 3 est verticale. R 'a des valeurs de 0-1 pour les régimes d'extension, 1-2 pour les régimes de décrochement, et 2-3 pour les régimes de compression. A cette ncipales enregistrements de tsunami dans les niveaux géologiques a été développées récemment. En catastrophiques côtiers liés utilisation des équations de Folk (1968) incluant la sélection de la taille des grains de sédiment, la détermination des espèces fossiles (notamment foraminifères, gastéropodes et lamellibranches, des analyse aux rayons X des dépôts de sondage carottés et détermination des contenus minéralogiques par la méthode XRD donnant des standards PDFs (obtenus à partir des radiation Cu ), des mesures des proportions en matière organique, et des mesures de susceptibilité magnétique des niveaux géologiques. Ces travaux sont complétés feldspath), charbon, os, test de fossile, matière organique et pour des datations isotopique OSL-TL et C 14 nécessaire pour la datation des niveaux géologiques. 3) La troisième étape concerne la méthodologie de modélisation des tsunamis. La modélisation du tsunami a été réalisée à l'aide du logiciel Mirone développé par Luis (2007) version mise à jour 2.7 la dernière mise à jour le 22 octobre 2016. Ce logiciel utilisait le code TINTOL (NSWING) pour effectuer le tsunami modélisation de la propagation et de l'inondation ''. Le code modélise la propagation des tsunamis en utilisant la grille de bathymétrie (telle qu'utilisée dans cette étude des données de gebco 2014 de 30 secondes d'arc) et identifie la déformation initiale par le modèle d 'Okada (1985). Un événement tsunamigène a été examiné pour étudier l'effet de l'emplacement, la direction, le temps de voyage et la hauteur vers la côte égyptienne. Les caractéristiques des tsunamis, telles que les temps de déplacement et la distribution de la hauteur des vagues, sont calculées, ce qui est utile pour évaluer le risque de tsunami. Ceci est fait en utilisant les zones d'inondation estimées et la comparaison avec la hauteur et le dépôt des vagues du tsunami pour aider à déterminer l'intensité des séismes tsunamigènes et leur impact sur la côte nord de l'Egypte.

Le chapitre III traite de la sismotectonique sismotectonique de la partie nord de telles que [START_REF] Bohnhoff | Deformation and stress regimes in the Hellenic subduction zone from focal mechanisms[END_REF], Delvaux, 2010[START_REF] Heidbach | Global crustal stress pattern based on the World Stress Map database release[END_REF][START_REF] Tingay | Present-day stress-field rotations associated with evaporites in the offshore Nile Delta[END_REF][START_REF] Meghraoui | Active faulting and transpression tectonics along the plate boundary in North Africa[END_REF][START_REF] Nocquet | Present-day kinematics of the Mediterranean: A comprehensive overview of GPS results[END_REF]et Hussein, 2013). L'installation de nouvelles stations GPS en Egypte complète l'image de la déformation active dans le coin nord-est du continent africain et du déplacement vers le nord de la Nubie nord-est par rapport à l'Eurasie [START_REF] Mcclusky | Global Positioning System constraints on plate kinematics and dynamics in the eastern[END_REF][START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF][START_REF] Mahmoud | GPS evidence for northward motion of the Sinai block: Implications for E. Mediterranean tectonics[END_REF][START_REF] Saleh | New constraints on the Nubia-Sinai-Dead Sea fault crustal motion[END_REF][START_REF] Pietrantonio | Kinematics of the Suez-Sinai area from combined GPS velocity field[END_REF].

Nos travaux de collecte de solutions de plans de fautes et de calcul des inversions de contraintes des paramètres de défaut à l'aide du logiciel Tensor version 5.8. WSW (Abdel Aal et al., 1994).

Les plus grands séismes historiques de la marge continentale égyptienne sont les tremblements de terre 320 et 956, tandis que le tremblement de terre instrumental le plus important a eu lieu le 12 septembre 1955 avec Ms 6.7 (Costantinescu et al., 1966) [START_REF] Maamoun | Detailed Studies of 12 October, 1992 Earthquake[END_REF]Hussein, 1999) 1961).

Les deux autres zones des sources de tsunamis moins actives sont l'arc chypriote et la marge continentale égyptienne. La magnitude la plus élevée rapportée dans les catalogues de tremblements de terre pour Chypre est de 7,5 et se réfère au séisme du 11 mai 1222, AD.

Ce tremblement de terre a été suivi par de faibles impacts de tsunami le long de la zone côtière égypto-méditerranéenne Ambraseys (1995). Les séismes les plus importants se sont produits dans la marge continentale égyptienne, par exemple le tremblement de terre d'Alexandrie en mer, le 6 septembre, le 6 septembre 1955 (Hussein et al., 2005). Il est situé dans le cône sédimentaire du Nil qui présente un potentiel de glissements de terrain tsunamis [START_REF] Garziglia | Mass transport deposits on the Rosetta province (northwest Nile deep-sea turbidite system, Egyptian mar-gin): characteristics, distribution and potential causal processes[END_REF]. (Abu Fida, 1329;Guidoboni et Comastri, 2005). en testant les ruptures de failles calculées par [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF] et Pagnoni et al. (2015).

Les amplitudes des tremblements de terre ont été estimées égales ou supérieures à la magnitude la plus élevée enregistrée à l'époque historique (tableau 4 Mes résultats sont comparés avec des études antérieures de (Hamouda, 2006) pour la côte égyptienne ; [START_REF] Mohammed | Impacts on Egyptian Coastal zones Eastern Mediterranean Tsunamigenic Earthquakes and their Geology[END_REF], Pagnoni et al., 2015) dans le cas du scénario de l'arc hellénique oriental et pour l'arc hellénique occidental (Hamouda, 2009, Shaw et al., 2008, et Pagnoni et al., 2015). Mes résultats sont en accord avec la modélisation de [START_REF] Mohammed | Impacts on Egyptian Coastal zones Eastern Mediterranean Tsunamigenic Earthquakes and their Geology[END_REF] pour la hauteur des vagues à Salloum, Alexandrie, Damiette en cas de scénario oriental et semblent être différentes du résultat de (Hamouda, 2005et Pagnoni et al., 2015) . Mes résultats concordent bien avec la taille de l'onde de tsunami déduite du modèle de Shaw et al., (2008) Par exemple, selon [START_REF] Salamon | Potential tsunamigenic sources in the eastern Mediterranean and a decision matrix for a tsunami early warning system in Israel[END_REF], les messages peuvent être liés à des distances cas des zones côtières égyptiennes, nous considérons que l'arc hellénique oriental (EHA) et l'arc hellénique occidental (WHA) sont le message régional de 100-400 km.

2) L'ensemble de la zone hellénique de subduction représente un risque sérieux de 2006) Hamouda(2009), Shaw et al., (2008[START_REF] Mohammed | Impacts on Egyptian Coastal zones Eastern Mediterranean Tsunamigenic Earthquakes and their Geology[END_REF], Pagnoni et al (2015) xli

Chapter I Introduction

The understanding of seismotectonic, earthquake faulting and the recurrence of paleotsunami in northern Egypt is the first step in seismic hazard assessment and risk mitigation. The instrumental and historical seismicity catalogues of the Eastern Mediterranean and northern Egypt help to identify the main seismic and tsunamigenic zones. Numerous destructive earthquakes and tsunamis have occurred in northern Egypt and where seismicity was studied by Sieberg, 1932;Ismail, 1960;Maamoun et al., 1984;[START_REF] Kebeasy | Seismicity[END_REF]and Abou Elenean, 1997. The seismic activity is reported to occur in narrow belts (Levant-Aqaba, Northern Red Sea, Gulf of Suez, Eastern Mediterranean and the Egypt continental margin) that represent the major tectonic trends in northern Egypt (Fig. 1).

According to [START_REF] Papazachos | Seismicity of the Aegean and the surrounding area[END_REF][START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF][START_REF] Riad | Ancient earthquakes from some Arabic sources and catalogue of Middle East historical earthquakes[END_REF], several kinds of disasters were caused in Syria and Egypt, especially in Alexandria where a house was ruined and 60 m of the city wall with 27 towers were destroyed (this was mentioned in the Arabic historical documents (Abu El Fida, 1329). Damage was also seen in Peloponnese in the northwest of Crete and islands in the Aegean sea. The sea struck the city with strong force destroying the building and killing theinhabitants in the capital city of Heraklion in the northeastern Crete. This damage happened during the earthquake which was followed by a strong tsunami on 8 August 1303. The other example of a large damaging earthquake was on 21 July 365 which was also followed by a strong tsunami with the biggest damage reported in Greece, southwest Crete and Alexandria in the Nile Delta. The houses were destroyed and human lives were lost and the ships were driven by strong flooding in Alexandria city.

As the first objective of this thesis, I compiled the focal mechanism solutions and calculated the stress inversions from the seismicity catalogue of Egypt, searched for and mapped active faults, and used borehole data to develop a seismotectonic analysis from the stress distribution in my study region. The seismological data and related focal mechanisms are considered as an excellent source of information on the stress direction in the crust, which gives accurate pieces of information on the present-day stress field in the Eastern Mediterranean region and northern Egypt. Several studies deal with the seismotectonic and stress inversions in North Africa and Eastern Mediterranean such as [START_REF] Bohnhoff | Deformation and stress regimes in the Hellenic subduction zone from focal mechanisms[END_REF]Delvaux, 2010;[START_REF] Heidbach | Global crustal stress pattern based on the World Stress Map database release[END_REF][START_REF] Tingay | Present-day stress-field rotations associated with evaporites in the offshore Nile Delta[END_REF][START_REF] Meghraoui | Active faulting and transpression tectonics along the plate boundary in North Africa[END_REF][START_REF] Nocquet | Present-day kinematics of the Mediterranean: A comprehensive overview of GPS results[END_REF]and Hussein, 2013). The installation of new GPS stations in Egypt completes the picture of the active deformation in the north-eastern corner of the African continent and on the northward motion of northeast Nubia with respect to Eurasia [START_REF] Mcclusky | Global Positioning System constraints on plate kinematics and dynamics in the eastern[END_REF][START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF][START_REF] Mahmoud | GPS evidence for northward motion of the Sinai block: Implications for E. Mediterranean tectonics[END_REF][START_REF] Saleh | New constraints on the Nubia-Sinai-Dead Sea fault crustal motion[END_REF][START_REF] Pietrantonio | Kinematics of the Suez-Sinai area from combined GPS velocity field[END_REF]. The north of Egypt has been affected by large earthquakes like in Cairo in 1992 (Mw 5.8), Shadwan, 1969(Mw=6.1), Gulf of Aqaba, 1995 (Mw=7.2) and by other historical large earthquakes and tsunamis from the Eastern Mediterranean region. The largest earthquakes are recorded in historical documents and an updated catalogue of the events of Santorini ~1600 BC, 21 July 365, 8 August 1303, and 24 June 1870. Since the beginning of the 20th century, many efforts have been directed towards the establishment of a reliable catalogue of historical seismicity based on the retrieval and assessment of original sources of information e.g. (Poirier and Taher, 1980;Soloviev et al., 2000;Ambraseys, 2009;Guidoboni and Ebel, 2009).

The second main objective of this work is the identification of tsunami deposits by analyzing surface sediments (Holocene age) collected using core drill holes and by comparison with current tsunami deposits observed elsewhere (Sicily, Algeria, Tohoku, Sumatra). The complexity of the coastal dynamics is taken into account by the study of coastal sedimentary processes, paleoenvironmental and sea level fluctuations during the Holocene. Indeed, the existence of marine fossils in a continental environment associated with the development of species such as ostracods, diatoms, gastropods, aquatic plants may indicate long-term salinity changes associated with sudden tsunami floods [START_REF] Kortekaas | Distinguishing tsunami and storm deposits: An example from Martinhal, SW Portugal[END_REF].

The research of paleotsunami deposits consists in the identification and dating of tsunami deposits developed through testing, systematization and formalization. This work is usually carried out following a multidisciplinary approach testing several methodologies.

Interesting and promising results are expected from an original combination of geomorphology, geology with coring of deposits, macrofossils determination, X-ray scanning, geochemical analysis, microscopic, magnetic susceptibility measurements, etc.

Several studies have been developed for the identification of paleotsunami in the last 20 years using different methodologies. For example, along the coast of Kiritappu, Japan, Nanayama et al.(2003) identified sand sheets, extending 3 kilometres inland, that show large tsunamis with coastal inundation every 500 years on average, between 2000 and 7000 years ago. Similarly, a study of a 7000-year-long record in a coastal lake in Oregon (western USA), [START_REF] Kelsey | Tsunami history of an Oregon coastal lake reveals a 4600 yr record of great earth-quakes on the Cascadia subduction zone[END_REF] identified 12 paleotsunami deposits over the past 4600 years.

Other long records of multiple tsunamis have been studied in Chile (Cisternas et al., 2005).

Along the coast of South Andaman Island, India, Malik et al.(2015) identified three historical earthquakes and associated transoceanic tsunamis during the past 1000 years, depending on the stratigraphy of deposits and related dating. In the Mediterranean, among paleo-tsunami studies, De Martini et al. (2012) identified two tsunamis deposits during the first millennium BC and another one in 650-770 AD and estimated an average recurrence interval for strong tsunamis of ca. 385 years (using chronology include C14, Pb 210 and Cs 13, OSL and tephrochronology) along the eastern coast of Sicily, Italy. Along the Algerian Coast, [START_REF] Maouche | Large boulder accumulation on the Algerian coast evidence tsunami events in the western Mediterranean[END_REF] identified the presence of large boulders in Tipaza to Dellys to be related to tsunami events in 419 AD and 1700 AD using radiocarbon dating of bioindicators. Along the Egyptian coast, Shaha-Hosseini et al. (2016) identified coastal boulder accumulations between Alexandria to Marsa Matrouh and with boulders weighing up to 23 metric tons. By C 14 dating of (Vermetidae and Dendropoma ) shells found in these the large boulders, it was found that they were transported by the historical tsunami of 8 August 1303 AD.

It seems that Egypt is lack of tsunami investigations for the tsunami deposits which are well documented historically. The field surveys of the coastal landscape all around the Mediterranean coasts should allow 1) the recognition of paleo-tsunami deposits and landforms, 2) the evaluation of tsunami intensity and frequency, and 3) the propagation direction that may constrain the tsunamigenic source area.

At the present, paleotsunami data exist only for a limited number of seismically active regions of the world. The Hellenic arc and related subduction zone are considered as the hazardous source for tsunamis that may have affected the northern Egyptian coast in the past and would generate tsunami events in the future. It was supposed that the Thonis -Heracleion city sunk due to a tsunami event that occurred in the past (??). This city was founded in 331 BC and was a port of entry to Egypt and Nile River for all ships coming from the Greek region. A strong earthquake occurred on 21 July 365 located in the western segment of the Hellenic arc with evidence of up to 9 m of uplift and tilting in Crete Island, [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF]. This event caused a tsunami that devastated the city of Alexandria, Egypt and sent a wall of water across the Mediterranean Sea toward the north African coast and the entire eastern Mediterranean including southern Italy (Ambraseys, 2009). Ships in the harbour at Alexandria were overturned as the water near the coast receded suddenly. Reports indicate that many people rushed out to loot the hapless ships (this was mentioned by Ammianus Marcellinus who lived during that time in Ambrayses (2009). The tsunami wave then rushed in and carried the ships over the sea walls, many landing on top of buildings. In Alexandria, approximately 5,000 people lost their lives and 50,000 homes were destroyed.

The earthquake on 8 August 1303 was considered the second largest earthquake and tsunami that affected the Egyptian coast.Old documents describing the disaster of the 1303 tsunami event, concentrate on the frightening effects of that exceptional seismic tidal wave (tsunami) which struck many localities in the Mediterranean basin (Ambrayses 2009). Guidoboni and Comastri(2005) suggested that this extensive sea wave was caused by an earthquake and with its epicenter between the islands of Crete and Rhodes. Therefore, the fieldwork, which includes coring and trenching, was carried out to identify the tsunami deposits along the coast of two investigated sites: El Alamein and Kefr Saber. The low topography and limited human occupation of this region favour the preservation of tsunami deposits, especially west of Alexandria. The field investigations were multidisciplinary and include geomorphology and geology, coring with X-ray, petrochemical and magnetic susceptibilities measurements. The dating was done for collecting samples of organic matter, fossils, charcoal, plant remains and roots.

Tsunami modelling was carried out using Mirone software developed by Luis (2007) update version 2.7 the last update on 22 October 2016. According to Luis (2007) The chapters of my thesis present three key items: 1) the seismotectonic in the Eastern Mediterranean and northern Egypt; 2) the paleotsunami works in the northern Egypt through identifying the tsunami layers; and 3) the modelling of two expected tsunami scenarios that faced the northern Egypt in the past and may affect it in the near future.

The first chapter introduces and presents the importance and the aim of my study.

While the second chapter introduces the methodologies used in this study and the main definitions in seismotectonic, paleotsunami, modelling and scenarios for tsunamis.

The third chapter I calculated the present day stress regime in northern Egypt from the collected focal mechanisms using Tensor software version 5.8.5 developed by [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF]Delvaux et al. ( , 2010)).

The fourth chapter discusses the paleotsunami records in the north Egyptian coast during successive fieldwork trips. In addition to, using the laboratories analysis and different measurements to find the tsunami signatures.

The fifth chapter deals with the numerical modelling of two worst-case scenarios built up and processed by Mirone software developed by Luis(2007) Chapter II Methodology 1-Seismotectonic methodology seismotectonics consists of the study of active tectonics and their relationships with earthquakes, active faulting and deformation along faults or active regions. It seeks to correlate the active faults with seismic activity in a certain region through the analysis of combined regional tectonics, recent instrumentally recorded events, accounts of historical earthquakes, focal mechanisms, stress tensor and geodynamics. The compilation of such information helps to identify the main active zones and the possible tsunamigenic zones that may affect northern Egypt. In this study, the steps of the seismotectonic analysis were carried out as follows:

1) Collection of the seismicity data and focal mechanisms of magnitude M L the continental margin and M L from updated earthquake catalogue.

2) Tracing of active faults and geological units from Egyptian geological structural maps EMRA, (2008) using ArcGIS V10.2 to identify the active tectonic zones.

3) Stress tensor inversion is calculated using Stress Tensor inversion Wintensor software version 5.8.5 [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF](Delvaux et al., , 2010)).

4) Construction of a stress field pattern and GPS map of the study area.

Among the steps of my seismotectonic study, I will briefly describe my procedure to calculate the stress inversion method in northern Egypt. While the main definition and details in the methodology of focal mechanisms and stress inversion (i.e Right Dihedron method and the Rotational Optimization method) will be described in Appendix F.

1.1.Stress inversion

According to [START_REF] Ramsay | The techniques of modern structural geology[END_REF] ''Stress tensor was identified as an inverse method for distinguishing the stresses from fault slip data obtained from outcrops, borehole cores or active seismic clusters''. Stress field studies were developed recently by adding in situ measurements, fault slip data and the focal mechanisms of earthquakes.

Researchers have estimated regional stresses using different methods, for example, using direct inversion, iterative and grid search methods. These methods help in the reconstruction of past and present stresses from fault kinematics and/or earthquake focal mechanism data [START_REF] Angelier | Determination of the mean principal directions of stresses for a given fault population[END_REF][START_REF] Angelier | Tectonic analysis of fault slip data sets[END_REF][START_REF] Reches | Faulting of rocks in three-dimensional strain fields[END_REF]Vasseur et al., 1983;Gephart and Forsyth, 1984;[START_REF] Carey-Gailhardis | A numerical method for determining the state of stress using focal mechanisms of earthquake populations: application to Tibetan teleseisms and micro seismicity of southern Peru[END_REF].

In my study area, I calculated the stress inversion of the six main active seismic zones in northern Egypt using the Delvaux method [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF] and Delvaux and Barth(2010). I used the Tensor inversion software version 5.8.5 Delvaux (2003) This stress tensor study was considered as an extension and update of previous studies using inversion of focal mechanism data like (Abou Elenean, 1997;Hussein, 2013;[START_REF] Emad Mohamed | Earthquakes focal mechanism and stress field pattern in the northeastern part of Egypt[END_REF].

Paleotsunami, methodology

In 1980, the tsunami researchers around the world speculated that tsunamis do not leave deposits. However, the reports of several pre-1980s surveys indicated that tsunamis eroded and deposited sediments, not only sand but also responsibly large boulders and coral debris. Since the 1990s, and certainly, since 2004, there is no doubt that tsunamis erode and deposit sediments in the stratigraphy records. In the 1990s, post-tsunami surveys started to take observations on geological tsunami deposits e.g., [START_REF] Dawson | The diatom biostratigraphy of tsunami sediments: examples from recent and middle Holocene events[END_REF][START_REF] Minoura | Sequence of sedimentation processes caused by the 1992 Flores tsunami; evidence from Babi Island[END_REF][START_REF] Bourgeois | Bathymetric and topographic effects of the 1969 Ozernoi tsunami: runup evidence from tsunami deposits at Stolbovaya, Kamchatka, Russia[END_REF][START_REF] Matsutomi | Field Survey of the 1996 Irian Jaya earthquake tsunami in Biak Island[END_REF][START_REF] Gelfenbaum | Erosion and sedimentation from the 17 July, 1998 Papua New Guinea tsunami[END_REF][START_REF] Rothaus | Regional considerations of coastline change, tsunami damage and recovery along the southern coast of the Bay of Izmit (the Kocaeli (Turkey) earthquake of 17 August 1999)[END_REF].

Since 1900 (the beginning of instrumental location of earthquakes), most tsunamis have been generated in Japan, Peru, Chile, New Guinea and the Solomon Islands (Clague et al., 1994;[START_REF] Sato | Onshore Tsunami Deposits Caused by the 1993 Southwest Hokkaido and 1983 Japan Sea Earthquakes[END_REF]Nishimura and Miyagi, 1995;[START_REF] Dawson | Tsunami deposits[END_REF]. Some historic tsunami events have also been identified in the Atlantic Ocean/northwest Europe [START_REF] Haslett | Reconnaissance of historic (post-AD 1000) highenergy deposits along the Atlantic coasts of southwest Britain, Ireland and Brittany, France[END_REF]. A much smaller number of tsunamis have been generated in the Atlantic and Indian Oceans.

In the Indian Ocean, the Indo-Australian plate is being subducted beneath the Eurasian plate at its eastern margin (Gunathilake, 2005) with the Indian plate moving northeast at around 6 cm per year at an oblique angle to the Java Trench with Sumatra sliding over the top of the subducting Indian oceanic plate [START_REF] Sandiford | Evaluating slab-plate coupling in the Indo-Australian plate[END_REF][START_REF] Richards | New radiometric ages for the Early Upper Palaeolithic type locality of Brno-Bohunice (Czech Republic): comparison of OSL, IRSL, TL and 14C dating results[END_REF][START_REF] Mosher | Deformation of the northern Sumatra accretionary prism from high-resolution seismic reflection profiles and ROV observations[END_REF]. Large magnitude earthquakes occur as a result of this convergence. Field surveys outline the geological and geomorphic effects of the 26 December 2004 Indian Ocean tsunami including Szczucinski et al. (2005Szczucinski et al. ( , 2007) ) studies of the environmental and geological impacts of the tsunami on the Thailand coast. [START_REF] Kurian | Inundation characteristics and geomorphological impacts of December 2004 tsunami on Kerala coast[END_REF] describe inundation and geomorphological impacts of the tsunami on the SW coast of India, documenting before and after beach profiles and quantifying erosion and deposition by the tsunami. [START_REF] Kench | Geological effects of tsunami on mid-ocean atoll islands: The Maldives before and after the Sumatran tsunami[END_REF] describe geological effects of the tsunami on the Maldives, a set of low-lying, mid-ocean coral islands, where deposition dominated erosion.

The December 2004 tsunami has generated a new view of geological and geomorphological studies, many using techniques not available when other great tsunamis occurred, for example, like Alaska 1964, Chile 1960, and Kamchatka 1952, and addressing questions about the tsunami deposits.

In a number of historical cases, seaward-directed flow and evidence of seaward flow such as flopped-over plants have been observed on the coastal plain. The drawdown phase of the tsunami is typically slower than the uprush, however, outflow tends to be concentrated in topographic lows such as channels. Terrestrial debris from tsunami outflow has been observed and photographed in the nearshore region in many historical cases. It is likely that on the shelf, a tsunami deposit looks similar to and might be confused with a deposit from a flooding river mouth e.g., [START_REF] Wheatcroft | Oceanic flood deposits on the northern California shelf: large-scale distribution and small-scale physical properties[END_REF], or a storm-surge return flow e.g., [START_REF] Aigner | Proximality trends in modern storm sands from the Helgoland Bight (North Sea) and their implications for basin analysis[END_REF].

Several criteria, based on tsunami signatures, are used to identify tsunami deposits in the sediment cores and trenches. The following summarizes the most common tsunami signatures in sediments as evidenced from previous tsunami studies : a) A sharp lower contact is a common feature found in high-energy wave deposits regardless of the exact hydrodynamic process.

b) Ripped-up clasts of underlying strata are very common in tsunami sediments [START_REF] Bridge | Sedimentary features of tsunami deposits[END_REF][START_REF] Wang | Erosional and depositional characteristics of regional overwash deposits caused by multiple hurricanes[END_REF]. c) Concentrations of major heavy minerals such as tourmaline or zircon are entirely sited 2009); other observations rely on reduced heavy mineral content [START_REF] Dahanayake | Geological evidence for paleo-tsunamis in Sri Lanka[END_REF].

d) The macro and microfaunal assemblages (benthic foraminifera, ostracods, gastropods, shells) within tsunami deposits tend to contain many broken reworked fossils from a wide range of marine, brackish and even freshwater habitats [START_REF] Kortekaas | Distinguishing tsunami and storm deposits: An example from Martinhal, SW Portugal[END_REF].

e) The geochemical pattern of an overwash sediment body solely proves marine flooding but does not represent a criterion to distinguish between tsunami or storm origin (Chagué-Goff., 2010).

f) The measurements of magnetic susceptibility may provide definite signatures of paleo-tsunami deposits. According to Font et al. ( 2010), the magnetic susceptibility data indicate that the tsunami deposits were characterized by a very low magnetic susceptibility values linked to amounts of sand (i.e. paramagnetic) originated from the littoral dunes and mixed with inland sediments with tsunami wave reworked.

Examples of cores and trenching in tsunami and paleotsunami research

Some recent tsunami events, for example, the 26 December 2004 Indian Ocean tsunami or the 11 March 2011 Tohoku Japan tsunami, have provided a valuable view for future studies on old tsunamigenic deposits [START_REF] Paris | Coastal sedimentation associated with the December 26, 2004 tsunami in Lhok Nga, West Banda Aceh (Sumatra, Indonesia)[END_REF].

These two recent tsunamis resulted in more than ~ 184,167 deaths, and the total or partial destruction of more than 250,000 buildings, including harbours, seawalls, and other coastal protection structures [START_REF] Nandasena | Reassessment of hydrodynamic equations: minimum flow velocity to initiate boulder transport by high energy events (storms, tsunamis)[END_REF]. Fatalities from the Indian Ocean tsunami and earthquake in Indonesia alone totalled 128,645, with more than 37,063 persons m at Osawa [START_REF] Haraguchi | Detailed maps of the impacts of the 2011 Japan tsunami[END_REF]. The resulting tsunami deposit was recognized by beach and beach ridge sourced sand and gravel found up to 600 m inland in December 2012. Tsunami deposits were identified at by their grain composition, size, and roundness, which widely differed from those of the background deposits (e.g., peat and debris flow deposits). They also used the radiocarbon dating and tephra analysis to establish the geochronology in the KYD-trench wall sediments and to correlate tsunami deposits with historical tsunami events. [START_REF] Borrero | Tsunami inundation modeling for western Sumatra[END_REF] examined the tsunami deposits of 2004 Indian Ocean event in pits and trenches along 800 km of the shoreline from Breuh Island to Teluk Bandera in Batu Islands three months after this event. They examined the paleotsunami deposits by push cores. Bent vegetation, within or at the base of tsunami deposits, was used to determine flow direction. These tsunami deposits were composed primarily of sand and their thickness varied from site to site. Deposits were usually composed of multiple layers; the total thickness may reflect deposition during multiple waves and/or during uprush and return flow. The causes of the observed variability in grading include differences in the processes of deposition suspension versus bed load and in the spatial and temporal gradients in transport. The typical thickness was 5-20 cm, while the greatest thickness was 70 cm. The maximum tsunami runup height was 13 m at the northern Simeulue Island. My studies of tsunami deposits from coring and trenching described as follows:-

a. X-ray scanning

The x-ray scanning method used in chest scanning was used as an effective tool to identify small-scale sedimentary structures (e.g. sharp contacts, convoluted layers, etc.) which were not clearly detected through sedimentological changes, as well as the presence of bioturbation, or a fining upward of grain size and possibly erosional, basal contact like in paleotsunami studies such as [START_REF] Bertrand | Sedimentology of Hersek Lagoon, NW Turkey. Relationships with Tsunamis in the sea of Mamara[END_REF][START_REF] Gerardi | Geological Record of Tsunami Inundations in Pantano Morghella (South-Eastern Sicily) Both from near and Far-Earth System[END_REF].

In this study, 12 cores of a total of 24 tubes were scanned in the Royal Scanning Laboratory in Helwan, Cairo. Each 40 cm of the tube was scanned with a different level of radiation (the x-ray spectra ranged from 80-100 KV until the best contrast at the lowest radiation dose was achieved).

Each 40 cm of the tube were scanned with overlaps of 5 cm and then pasted together with Adobe Illustrator V. 6 software. Details like fossil content arrangements and stratigraphic markers like contacts, grain size were recognized along the cores in my studied area and indicate tsunami layers (see Chapter V). Moreover, the tube of unclear x-ray scanning may reflect high sedimentation rate.

2.2.b. Magnetic susceptibility

According to Handely(2000) ''The magnetic susceptibility of a mineral is defined as induced magnetization per volume unit of the measured sample (M), an applied magnetic field intensity (H):

omitting the 10-5 multiplier!)''.

Magnetic susceptibility (MS) measurements were used as a good tool in identifying the plaeotsunami deposits for example [START_REF] Bertrand | Sedimentology of Hersek Lagoon, NW Turkey. Relationships with Tsunamis in the sea of Mamara[END_REF]; Font et al. ( 2010); [START_REF] Polonia | Mediterranean megaturbidite triggered by the AD 365 Crete earthquake and tsunami[END_REF]. The main idea of these works of MS measurements is that it detects a tsunami layer as having the lowest magnetic susceptibility values with peak values reflecting sediments rich in carbonates and high organic matter. In addition, low MS values, give evidence that a core is characterized by a higher sedimentation rate and high fossil content.

Magnetic susceptibility measurements provide a quantifiable, nondestructive and economic method for inter-correlation between cores. The MS variations of marine and lacustrine sediments indirectly reflect the proportion of biogenic (carbonates and silica) to lithogenic (clay and detrital) components [START_REF] Sangode | Godavari source in the Bengal fan sediments: Results from magnetic susceptibility dispersal pattern[END_REF]. In my study, magnetic susceptibility measurements were carried out using a Bartington MS-2 system (Fig. 2) to measure cores with a sampling rate of 3 cm. The measurements were carried out in the Geomagnetic Laboratory of the National Research Institute of Geophysics and Astronomy (NRIAG, Helwan).

Corrections for air were done using drift during the measurement period being linear and each measurement in the sequence is corrected by subtracting the estimated air reading at that time. The correction air value estimated for each point as:

Air value = first air + (final air * n/N) N = number of reading +1

The correction is done using the Multisus software supplied by Bartington instruments.

Fig. 2: Bartington MS-2 Magnetic Susceptibility measurements.

2.2.c. Sampling and Macrofossil detections

We collected samples in this study as follows, first, 120 samples were collected from core tubes every 15 cm for the geochemical analysis (Fig. 3) including grain size, bulk mineralogy and totally organic and inorganic matter. Each sample was 25 grams, weighed using a sensitive balance. Then the samples are sent to Central Metallurgical Research Center Laboratory, Cairo, Egypt. This procedure of the sample analyses is described in detail in the next section. Second, sampling was used for macrofossils detection and carbon dating. The sediments contain several species of gastropods and bivalves (broken or in fragments) bones, charcoal, minerals (crystals like anhydrite that reflect the lagoon environment) and unidentified constituents (Fig. 4). Identified gastropods species are Conus and Tympanotonos fuscatus species, which reflect the lagoon environment. The collected samples helped to: (1) recognize sedimentary layers containing particles transported by tsunami (broken shells are more likely to be transported); and (2) to reconstruct the origin of the shells, as some of them are from lagoon environment and others are transported by waves and boulders to the shoreline like the Dendropoma (Fig. 4 N,O).

Fig. 3: Collected samples in this study of 25 grams for grain size and X-ray diffraction and totally organic and inorganic measurements Fig. 4: Photos of the collected samples from cores and trenches in the studied area.

d. Geochemical analysis

The geochemical pattern was traced across the cores to define the paleotsunami deposits. The 120 collected samples in 24 core tubes were analysed using grain size, X-ray diffraction, totally organic and inorganic matter measurements. The geochemical analysis will be described in brief as following:-

Grain size analysis

The samples were collected from the cores and weighed before being sent to Central Metallurgical Research Center Laboratory, Cairo. The procedures include separating the weighed samples through a series of sieves (or screens) from 0.75 to 1000 microns. The distribution of size particles is determined by weighing the material remaining on each of the sieves and dividing these weights by the total weight of the sample. A correction is made for the moisture content of the sample so that all calculations are based on dry weight. The method requires drying, washing, during a series of separations.

I calculated the grain-size distribution statistics with gun plot software and excel 2013 (see Appendix D). Grain-size statistical parameters and graphic representations are given units. Converting from microns to mm (as 1 micron = 10 -3 mm) to Phi units using the following equation: -= -log 2 (d) where d is grain diameter in millimetres

The calculated grain size analyses distribution parameters have been calculated

following Folk and Ward (1957) to determine to mean grain size, sorting, skewness, Kurtosis (see Appendix F for detailed equations). The most useful parameters of grain-size analysis for this study are the mean grain size and sorting. Extremely poor sorting reflects tsunami layers. Also, the high mean grain-size of sediments, which means coarser grain size, reflects high rich organic matter in cores analyses (see the section of coring analyses and interpretation in Chapter IV).

Total organic and organic matter TOC content can be measured directly or can be determined if the total carbon content and inorganic carbon contents are measured according to the following equation (Jones 1925).

In soils and sediments, the total carbon means, (Total Carbon = Inorganic Carbon + Organic Carbon)

In this study, the total organic and inorganic carbon are calculated by weight percent in cores. Organic carbon (Corg) in the sediments was analyzed at Central Metallurgical Research Center Laboratory, Cairo, Egypt using treatment with hydrogen peroxide H 2 O 2 .

This treatment was unlike combustion methods and it would not be expected to affect the combined water content or change of weight of the inorganic material (Jones,1925).

The samples were treated with hydrogen chloride HCl to calculate the inorganic carbon by note the loss of weight before and after treatment.

X-ray diffraction

According to [START_REF] Pecharsky | Fundamentals of Powder Diffraction and Structural Characterization of Materials[END_REF], X-ray diffraction (XRD analysis) is a very useful tool for the identification of bulk mineral phases in powder specimens in the form of powder thin-film samples. The key for identifying materials by this method is their unique crystalline structure.The XRD instrument was called an X-ray diffractometer see Appendix F for the details of methodology and theory.

In cooperation with the Central Metallurgical Research Center Laboratory, Cairo, the collected samples were mounted in X-ray specimen holder on glass slides. The powder specimens were stuck on a glass slide using double-sided tape or Vaseline. The machine is equipped with a Philips PW 1730 X-ray diffractometer (Fig. 5) to measure the samples in the studied area under target Fe, filter Mn, KV 30, Ma 20, with speed 1 degree.

The data were analyzed in a semi-quantitative way following Cook et al. (1975). The intensity of the most intense diffraction peak of each mineral (see AppendixB) was measured and the identification of crystalline substance and crystalline phases in a specimen is achieved by comparing the specimen diffraction spectrum with spectra of known crystalline substances (Table 1). X-ray diffraction data from a known substance (called fingerprint) are recorded as a powder diffraction file (PDF).

Most PDFs were obtained with Cu radiation Standard diffraction published by the International Centre for Diffraction Data (ICDD) and summarized in Table 1, and they are updated and expanded from time to time.

2.2.e. Radiocarbon dating

Radiocarbon is a defined as an isotope of carbon which is radioactive with and has a half-life of about 5730 years and has the symbol of C 14 [START_REF] Bowman | Radiocarbondating[END_REF].

The C 14 is produced by the interactions of cosmic rays with the atmosphere. The resulting radiocarbon combines with the atmosphere which is incorporated into plants and then by animals after they eat plants containingC 14 . When an organism dies, carbon stops being absorbed. As the C 14 radioactively decays to nitrogen, the remaining percentage remains as C 14 . Samples older than about 50,000 years have a C 14 concentration that is in practice too small to measure; so they cannot be dated via C 14 .

The C 14 dating of the samples in the natural environment should be corrected for the variations in the in the C 14 /C 12 ratio of the atmosphere, ocean, or another reservoir the sample was formed. Numerous calibration curves have been introduced by many authors in the last few years such as [START_REF] Reimer | IntCal09 and Marine09 radiocarbon age calibration curves, 0-50,000 years cal BP[END_REF][START_REF] Reimer | Selection and treatment of data for radiocarbon calibration: an update to the International Calibration (IntCal) criteria[END_REF].

In my study, 46 samples were collected from cores and trenches in both study areas (see Tables 1 and2 in Appendix E) for collecting samples and calibration dating curve using Oxcal,Bronk Ramsay 2013) for dating the paleotsunami deposits. These samples were sent to two laboratories (Poznan laboratory, Poland and Beta Analytical Laboratory, USA) for radiocarbon dating to identify dates of the historical tsunami layers. The collected samples were made of charcoal, plants (Fig. 6), bones, gastropods, shells and organic matter. The radiocarbon dating results of charcoal and organic matter were calibrated using Oxcal software (Bronk- Ramsay, 2009) with the IntCal13 calibration curve.

Fig. 6: Photo of plant remains that were dated in our study in the Beta Analytical laboratory.

3.Tsunami modelling

According to [START_REF] Power | Review of Tsunami Hazard in New Zealand (2013 Update)[END_REF] Tsunami modelling was defined as a set of mathematical formula that describes the physical characteristics of the tsunami to evaluate and predict the evolution of tsunami waves and their coastal impact. Tsunami models can be used to estimate the probable arrival times of tsunami, their amplitudes, inundation ranges, flow depths and/or current speeds. There are two main types of tsunami models: numerical models (i.e., computer-derived models) and empirical models .

When creating a numerical simulation, consideration should be given to the source mechanism and bathymetry grid in order to produce realistic and accurate results. As an example, there is a difference between using source parameters for local and far-field tsunamis to identify the local and far-field tsunamis run up. For far-field tectonic tsunamis, the line on the fault or even a point is sufficient to identify the runup height averaged over large distances. In contrast, local tsunamis require a full source identified by rupture area as well as consideration of temporal and spatial changes in the source parameters of the earthquake.

Numerical simulations have been developed and progressed during the past 30 years.

The ongoing research into developing the numerical tsunami models is aimed at giving better and faster computing of the origin of tsunami wave propagation, inundation or impact on the coastal zone. Examples of common modelling used are: submarine mass failure model by [START_REF] Hampton | Submarine Landslides[END_REF]; the Antonio Baptista model by [START_REF] Myers | Finite element modeling of the July 12, 1993 Hokkaido Nansei-Oki tsunami[END_REF]; TSUNAMI-Goto et al. (1997); the most famous model used in the world, Tsunami propagation and inundation model (Geowave) by [START_REF] Madsen | A new Boussinesq method for fully nonlinear waves from shallow to deep water[END_REF], [START_REF] Fuhrman | Numerical solutions of fully non-linear and highly dispersive Boussinesq equations in two horizontal dimensions[END_REF]; and Method of Splitting Tsunami (MOST) by [START_REF] Burwell | Diffusion and dispersion characterization of a numerical tsunami model[END_REF].

The most important task of the propagation modelling was to estimate the arrival time and wave heights. In addition, these models help us in understanding the behaviour of tsunamis, and to estimate the damage and tsunami risk.

My procedure in this study is to develop two simple scenarios based on the geological evidence observed at the paleotsunami investigation sites of Kefr Saber and EL Alamein (see Chapter IV). These two scenarios started from the Eastern and Western Hellenic arc tsunamigenic zone and affected the northern Egypt (see Chapter VI for estimated wave height and travel times). The scenarios were developed using Mirone software version 2.70 (updated by 22 October 2016; Luis, 2007), the software was created by the MATLAB tool and using TINTOL code. We create the initial wave by using two selective fault parameters for the eastern and western Hellenic arc sources (see chapter VI for details of the fault ruptures used i.e. location, length, width, depth, rake, slip). The Okada (1985) model are used to identify the co-seismic displacement in the Mirone software.

Five possible scenarios for both the eastern and western Hellenic arcs were developed and the best two scenarios were chosen based on recent large focal mechanism earthquakes in the Hellenic region with increasing the magnitude to reaches the magnitude of historical events of 21 July 365 and 8 August 1303. Then I compute the tsunami wave according to shallow wave theory acceleration of gravity, v is propagation velocity and h is depth (See details of equation in Appendix F) and using Mirone software to spread the tsunami across the bathymetry grid (30 arc seconds) in the study area (available from http://www.gebco.net/; Gebco 2014).

Concluding remarks

For the seismotectonic methodology, we collected instrumental and historical earthquake recordings, surface faults, tectonic and geological setting, and earthquake focal mechanisms data and GPS velocity vectors to give a general picture of the seismotectonic in the northern Egypt and adjacent areas of Eastern Mediterranean. We used the stress inversion method to calculate the present-day stress of six main active zones in the north of Egypt as a part of a study of the seismotectonic setting. To begin, we prepared a dataset of focal mechanisms from 1951 to 2016. We then used the right dihedron method and the rotational optimization method to calculate the four parameters of the Stress tensor: the -index regime.

For the paleotsunami methodology, different methods are used in my study to identify the paleotsunami deposits such as 1) X-ray scanning which used an x-ray spectra range of 80-100 KV to identify the broken shell fragments or identify the sharp contacts or sedimentation rate. 2) magnetic susceptibility measured by a Bartington MS-2 system with a sampling rate of 3 cm. The peak of magnetic susceptibility with values close to zero reflects the richness of organic matter and carbonates in paleotsunami deposits. 3) geochemical methods useful in determining the changes along the cores by grain size analysis to determine the mean and sorting using Folk and Ward (1957); bulk mineralogy used the xray diffraction method to identify the minerals and to determine the abrupt changes in mineral compositions and related source environment; total organic carbon is determined by treating with H 2 O 2 to identify the organic matter enrichment in the tsunami deposits.

For the tsunami numerical modelling, we test five scenarios for both the Eastern and Western Hellenic arc based on our main findings of deposits of the 21 July 365 and 8

August 1303 tsunamis. We used Mirone software developed by Luis (2007) and this program used the TINTOL model code to compute travel time and the wave height in the study area.

There are some problems and limitations in the applying these methodologies. The uncertainties in stress inversion determination were due to geological and mechanical errors which generally fall in the range of measurement errors (Dupin et al., 1993 and[START_REF] Pollard | Stress inversion methods: are they based on faulty assumptions[END_REF]. Moreover, a numerical quality index was evaluated to measure the accuracy of the results in the Tensor program based on the total number of data, the average slip ions kept [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF]. Although, the solution of the stress axes parallel to the fault plane was removed to increase the accuracy the solutions.

There are also some limitations and problems in the paleotsunami methodology. The radiocarbon dating method may have some uncertainty related to mixing or reworking of surrounding plant materials in the cores. The shells from both marine and land organisms consist almost entirely of calcium carbonate which often dissolves and recrystallize which could give errors in the dating of shell samples. The correction of reservoir effects was applied to shells and collected gastropods samples in my study area using (Oxcal, Bronk Ramsy 2013) software. We calculated Mediterranean database of dated shells and we applied thi 161 to correct the samples dating against reservoir effect in my studied area.

With respect to the tsunami modelling, most propagation models assumed that coastlines behave as perfect reflectors of tsunami waves. This assumption omits the natural dissipation of tsunami energy which occurs when they run-up against the shore (Dunbar et al., 1989). This leads to a gradual reduction of the accuracy of the model. This is a particular problem for modelling the effect of a tsunami from distant sources, as incoming waves may arrive over the course of several hours and interact with earlier waves, especially in between Alexandria and El Alamein.

Moreover, the characterization of the tsunami source and the resolution of the bathymetry data may represent uncertainty for tsunami modelling. The tsunami source problem is due to little source information availability. We overcome this problem because of the diversity of historical information and studies for the source locations for 21 July 365 and 8 August 1303 tsunami events.

Chapter III

Seismotectonic of northern Egypt

Introduction

Egypt is part of the northern African continent. It is affected by tectonic movements due to the proximity of the tectonic boundaries of the Eurasia, African and Arabian plates and significant seismic activity such as the Hellenic subduction zone. Northern Egypt is affected by the opening of the Red Sea and tectonic movement along the Gulf of Suez and Gulf of Aqaba-Dead Sea transform fault.

The seismicity of northern Egypt was studied by many authors among them Sieberg, 1932;Ismail, 1960;[START_REF] Gergawi | Seismicity of Egypt[END_REF]Maamoun et al., 1984;[START_REF] Kebeasy | Seismicity[END_REF]Abou Elenean 1997;[START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF] In their studies, the seismic activity is reported in narrow belts (Levant-Aqaba, Northern Red Sea, Gulf of Suez, Eastern Mediterranean, and Egypt continental margin) which represent the major tectonic trends in northern Egypt.

While the Western Desert and Nile Delta are characterized by low-level seismicity.

The seismicity data and focal mechanisms used in this chapter are collected for magnitude M L for the continental margin and for M L for inland in northern Egypt from the updated Egyptian earthquake catalogue (see references Tables 2,4,6,8 Bulletins of the Egyptian National Seismic Network for events which occurred after 1997 in Egypt. Additionally, published data on historical earthquakes was also considered e.g. [START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF]Guidoboni et al. 2009, andAmbraseys 2009).

In order to study the recent stress field of northern Egypt, we first collect all focal mechanisms in a catalogue and study the active faulting distribution. Secondly, we perform stress inversion using the Tensor program [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF]. This procedure depends on two major assumptions for the study region: a) the stress field is uniform and invariant in space and time, and b) earthquake slip occurs in the direction of maximum shear stress (Bott, 1959).

The aim of this chapter is to study the seismotectonic setting of the active seismic zone of northern Egypt through the analysis of late Quaternary geological and tectonic structures, their main faults trends, the seismicity through historical and instrumental data, focal mechanisms with stress distribution and active deformation with GPS data. This chapter will also deal with the geology and tectonics of the Eastern Mediterranean and the possible tsunamigenic sources in the Eastern Mediterranean active zones, which will be discussed in Chapter IV.

Geological and tectonic settings of the Eastern Mediterranean and the Egyptian continental margin

The present-day geological configuration of the Mediterranean region is the result of the opening and subsequent consumption of two major oceanic basins, the Paleo-Theys (mostly Paleozoic) and the Neotethys (Late Paleozoic-Mesozoic) and additional smaller oceanic basins (e.g. the Atlantic Alpine Tethys). This has occurred within an overall regime of prolonged interaction between the Eurasian and African-Arabian plates [START_REF] Robertson | Introduction: aspects of the geological evolution of the Eastern Mediterranean[END_REF][START_REF] Stampfli | Palaeotectonic and palaeogeographic evolution of the western Tethys and PeriTethyan domain[END_REF].

The Eastern Mediterranean is a tectonically complex basin and is a relic of the Mesozoic Neotethys Ocean (Garnfunkel, 2004) with its evolution strongly related to the active subduction along the Hellenic arc. The present tectonics of the Eastern Mediterranean was developed by the northward convergence of the African plate relative to the Eurasian at a rate of 1cm/yr while the Aegean Sea represents an extensional basin with opening rates in the order of 3.5-4 cm/year [START_REF] Mckenzie | Active tectonics of the Mediterranean region[END_REF][START_REF] Mcclusky | Global Positioning System constraints on plate kinematics and dynamics in the eastern[END_REF]. The African plate oceanic lithosphere is nowadays subducted along the two small Hellenic and Cyprian arcs.

The Hellenic Trench (Fig. 7) is parallel to the Hellenic Arc which consists of an outer sedimentary arc and an inner volcanic arc. The average distance between them is 120 km. The sedimentary arc (Hellenides Mts, Ionian Islands, Crete, Rhodos) connects

Dinarides and Hellenides mountains to the Tauride mountains in southwestern Turkey [START_REF] Benetatos | Focal mechanisms of shallow and intermediate depth earthquakes along the[END_REF]. Between the sedimentary and volcanic arcs South of Crete, the sea has a maximum depth of 2 km. The African oceanic lithosphere is subducting under the continental Aegean Sea lithosphere as part of the collision process of the Africa Eurasia plates. This leads to the formation of an inclined seismic zone a Benioff zone dipping to the NE to a depth of about 150 200 km [START_REF] Papazachos | Seismicity of the Aegean and the surrounding area[END_REF].

The Hellenic zone subduction appears to have been activated continuously since the late Cretaceous [START_REF] Arsenikos | Mechanism and timing of tectonic inversion in Cyrenaica[END_REF]. According to [START_REF] Benetatos | Focal mechanisms of shallow and intermediate depth earthquakes along the[END_REF], the distribution of focal mechanisms along the Hellenic Arc shows that: Crete Island (Fig. 7, [START_REF] Kokinou | A seismotectonic study for the Heraklion basin in Crete (Southern Hellenic Arc, Greece)[END_REF].

East of the Eastern Mediterranean region, the Cyprian arc forms a plate boundary between the Anatolian plate in the north and the Nubian and Sinai plates in the south. It has been deformed in late Cenozoic [START_REF] Ben-Avraham | Plate convergence in the Cyprian Arc[END_REF][START_REF] Kempler | Structures and kinematics in the northeastern Mediterranean: a study of an irregular plate boundary[END_REF].It is connected to the Hellenic arc in the west, and the Dead Sea Transform Fault and East Anatolian Fault in the east. A northward subduction of the African Plate beneath the Anatolian Plate indicates the existence of convergent mode along the western segment of the Cyprian arc [START_REF] Ben-Avraham | Plate convergence in the Cyprian Arc[END_REF]. The Anatolian block escapes from the collision between Eurasia and Arabia by moving south-westwards forming the Hellenic and Cyprian

Arcs (McKenzie, 1984). The geological structure in Eastern Mediterranean region is observed in the following bathymetry and structural map (Fig. 8). [START_REF] Cavazza | The TRANSMED Atlas. The Mediterranean region from crust to mantle geological and geophysical framework[END_REF][START_REF] Billi | Recent tectonic reorganization of the Nubia-Eurasia convergent boundary heading for the closure of the western Mediterranean[END_REF][START_REF] Benetatos | Focal mechanisms of shallow and intermediate depth earthquakes along the[END_REF], (see reference Table 14,15 of focal mechanisms data in Appendix A). (experiencing north-south compression), as demonstrated in several studies (Abu Elenean, 1997;Korrat et al., 2005;Abou Elenean and Hussein, 2007;[START_REF] Bosworth | North Africa-Mediterranean present-day stress field transition and implications for fractured reservoir production in the eastern Libya basins[END_REF]. The Herodotus abyssal plain (Fig. 8) is behind the Mediterranean Ridge. It is characterized by mud and salt diapers where rapid loading of shale and salt horizons by the clastics provided by the Nile River resulted in a progressive gravitational gliding of sedimentary wedge toward the North, coeval with the development of listric faults.

The tectonic framework and structural pattern of the Egyptian continental margin (Fig. 9) are the results of the interplay between three main fault trends: the northwestsoutheast Temsah zone; the northeast-southwest Rosetta zone; and the east-west to ENE-WSW continental fault trends (Abdel [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF]. These tectonic trends seem to belong to the reactivation of the basement faults. Other secondary fault trends are mapped and delineated in the west-northwest east-southeast and east-northeast west-southwest tectonic directions [START_REF] Selim | Subsurface structural trends of the offshoreNile Delta area, Egypt: Evidences from gravity and magnetic data[END_REF] in addition to the north-south Baltim fault trend [START_REF] Mosconi | Egypt Nile Delta and North Sinai Cenozoic tectonic evolutionary model: A proposal[END_REF][START_REF] Aal | Tectonic evolution of the Eastern Mediterranean Basin and its significance for hydrocarbon prospectivity in the ultradeepwater of the Nile Delta[END_REF]. explained the morphostructure in and around it [START_REF] Mcclusky | Global Positioning System constraints on plate kinematics and dynamics in the eastern[END_REF][START_REF] Loncke | Shallow structure of the Nile Deep Sea Fan: Interactions between structural heritage and salt tectonics; consequences on sedimentary dispersal[END_REF][START_REF] Gaullier | Salt tectonics in and around the Nile Deep-Sea Fan: insights from PRISMED II cruise[END_REF]. The Nile Deep Sea Fan is bounded by the Dead Sea shear zone to the east and the Cyprus convergent zone and the Mediterranean Ridge to the north.

The continental margin bordering the Eastern Mediterranean Sea is characterized by a narrow continental shelf extending from the shoreline seaward to the shelf edge at about 15 20 km. However, the shelf in the region between Rosetta mouth and Bardawil Lagoon becomes wider, where it ranges from 48 to 64 km [START_REF] Ross | Structure and sedimentary history of southeastern Mediterranean Sea Nile Cone area[END_REF]. The continental shelf in the western part is affected by a series of WNW trending faults. The present steep faulted continental slope, which has a rectilinear WNW orientation, varies in width from 34

to 56 km off western Egypt to about 20 km seaward of the Nile Delta. The coastal and continental shelf margin is offset abruptly to the WNW at several places, especially at the Gulf of Salloum and Gulf of Bomba.

In the area immediately seaward of the Nile Delta, the slope shows a fairly welldeveloped stratification with many closely spaced normal faults (Korrat et al., 2005). In principle, the continental margin can be considered a zone of weakness which experienced thinning of the crust during the Triassic period (Sofratome, 1984).

Geology and tectonics setting of Northern Egypt

The Mesozoic to the Tertiary tectonic history of northern Egypt had a significant effect on the formation of the Nile Delta, Cairo-Suez, Gulf of Suez, Gulf of Aqaba, and Sinai.

According to Abdel [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF] Sea led to a left lateral motion of Eurasia relative to Africa [START_REF] Robertson | Introduction: aspects of the geological evolution of the Eastern Mediterranean[END_REF].

This movement resulted in a system of NE-SW to ENE-WSW trending faults either normal faults or strike-slip faults with left lateral motion in northern Egypt, including northern

Sinai (Mesherf, 1990). These faults are parallel to the PelusiumMegashear system (Fig. 10, Neev and Hali, 1982). The NE trending Rosetta fault is parallel to Pelusium and the Jurassic NE to ENE faults along the extension of northwestern desert ''Qattara-Alamein'' ridge. These probably resulted in the right lateral oblique slip movement along the Rosetta fault during the Early Miocene (Abdel [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF].

The second phase, during the late Cretaceous-early Tertiary, the NW-SE oblique compression related to the closing of Tethys Sea as a result of Eurasia moving southeast relative to Africa [START_REF] Orwig | Tectonic framework of Northern Egypt and the Eastern Mediterranean region, 6th exploration and production conference[END_REF]. The oblique compression resulted in a series of an echelon NE-SW trending, double anticline belt (Syrian Arc structures) in northern Sinai and in Alamein and Abu Roash in the Western Desert, and NW to NNW extension faults parallel to the major contraction force that affected northern Egypt. The compressional stresses generated NW to NNW extension faults parallel to major compressional stresses that affected northern Egypt (Abdel [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF].

The third tectonic phase started from the late Eocene and up to recent times. At the beginning, the northeastward motion of the Arabian Peninsula yielded the opening of the Red Sea; subsequently, the rifting propagated toward the Gulf of Suez area. The rifting is thought to be cumulative in the early middle Miocene when stresses of the Red Sea rift were transferred along the Aqaba-Levant area generating a left lateral transform fault that extends through the Gulf of Aqaba northeastward to the Dead Sea, with a minor extensional component [START_REF] Steckler | Subsidence in the Gulf of Suez: implications for rifting and plate kinematics[END_REF]. The dominated motions were affected by three The main structural elements and the geology of the Northern Egypt can be summarized as the follows according to [START_REF] Said | Tectonic framework of Egypt[END_REF]Abdel Aaal, 1994 and[START_REF] Moustafa | Internal structure and deformation of an accommodation zone in the northern of the Suez rift and Red Sea[END_REF]:

a. Northern Egypt fold-fault Belt

The North Egypt fold-fault includes NE-SW oriented folds that affect the Mesozoic and older rocks in north Egypt. These folds are well exposed in the north Sinai [START_REF] Moustafa | North Sinai structures and tectonic evolution[END_REF] as well as the northern parts of the Eastern and Western Desert. This belt comprises:

i-The North Sinai folds and associated faults

This belt is described in detail in Moustafa andKhalil, 1989, 1990;[START_REF] Aal | Structural evolution and styles of the northern Sinai, Egypt. 11th Exploration & Production Conference[END_REF].

The belt is oriented NE-SW doubly plunging fold and is well exposed in north Sinai (Fig. measured from slickenside striations. In some places, the fault consists of several planes that are separated by very small distances and bind together to form a fault zone.

b. The northeast Desert (Cairo Suez area)

The Cairo-Suez area is located in the northern part of the Eastern Desert of Egypt and extends from the northern end of the Suez rift to the Nile valley. The Cairo-Suez area is affected by late Oligocene early Miocene deformation related to the opening of the Suez rift. As shown in the tectonic geological map (Fig. 12), this deformation is responsible for the E-W and NW-SE oriented normal faults [START_REF] Said | Tectonic framework of Egypt[END_REF]Abd-Allah,1992) associated with gentle folds affecting the upper Eocene and Miocene strata.

The south Cairo-Suez area is characterized by six slightly tilted fault blocks that affected the Middle Eocene formation. These blocks are Gebel Ataqa, Gebel Akheider, Gebel El Ramilya, Gebel Abu Trefia, Gebel Abu Shama, and Gebel Mokattam blocks.

c. The Nile Delta

The Nile Delta area is totally covered by the Quaternary deposits consisting of Nile silt, clay, sandy clay, sand, and gravel (Fig. 13). The Quaternary sediments in the Nile Delta have been classified into two rock units: a) Mit Ghamr formation (Baltim formation), which is overlain by the Bilqas formation [START_REF] Rizzini | Stratig-raphy and sedimentation of a Neogene Quaternary section in the Nile delta area[END_REF]; and b) Mit Ghamer formation composed of thick layers of quartzitic sand and pebbles that belongs to the Early to Middle Pleistocene and overlies the late Pliocene clay of the El-Wastani formation [START_REF] Said | Tectonic framework of Egypt[END_REF].

The thickness of Mit Ghamr formation (pre-Nile sediments) ranges from 250 m near Cairo to more than 1000 m north of the Nile Delta. The Bilqas formation is composed of medium to fine-grained sand, silt, clays and peats (New-Nile sediments; [START_REF] Said | Tectonic framework of Egypt[END_REF].

The Neogene history of the Nile Delta area is much better known than the history of the older units. Two major unconformities of regional extent subdivide the Miocene and Pliocene intervals. A thick sequence of Miocene fluviomarine and shallow marine deposits is present in the northern portion of the Nile Delta basin. The thickness exceeds 2000 m near the coast but decreases rapidly southward [START_REF] Said | Tectonic framework of Egypt[END_REF].

The Pliocene-Quaternary sediments uncomfortably overlay the Eocene-Miocene rocks throughout the Nile Delta and Valley. Generally, these sediments are composed of fluvial sands and clays with several gravel lenses. The surface agricultural clay layer caps these sediments inside the Nile Delta and Valley with variable thicknesses and alluvial fluvial lithology [START_REF] Said | Tectonic framework of Egypt[END_REF]. This layer has a thickness varying from less than 10 m to more than 28 m inside the Nile Valley and is more than 70 m thick in the Nile Delta. Also, the sandy to silty clay lithology of this layer in the Nile Valley changes into pure clay lithology mainly to the North of the Nile Delta. The Quaternary sediments in the Nile Delta increase in thickness northward, from about 100 m to more than 900 m in the offshore part of the delta forming the Nile cone [START_REF] Said | Tectonic framework of Egypt[END_REF]. The agricultural layer also increases to the north and shows interfingering features with the underlying sand body.

The tectonic history of northern Egypt from the Mesozoic through to the Tertiary had a significant effect on the formation of the Nile Delta. The seismic reflection profiles (from oil field data), reflected six major structural trends which delineate the present Nile Delta (Abdel [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF]. These trends have developed during the three main phases of the tectonic history of northern Egypt and described above (Figs. 9 and 13).

1) East-West Neogene Hinge Line.

2) Northeast-trending Rosetta fault trend.

3) Northwest-trending Temsah structural trend. [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF]geologic map EMRA, 2008) using ArcGIS map version 10.2.

3.3.d. The Suez Rift

The Suez Rift is located between Sinai and the northern part of the Eastern Desert (Fig. 10). This rift basin has a width of about 50-90 km and length of about 350 km and is occupied by the Gulf of Suez in the middle part. This has been traditionally referred to as the of Suez [START_REF] Robson | The structure of the Gulf of Suez (Clysmic) rift, with special reference to the eastern side[END_REF]. The Suez rift is dominated by NW-SE oriented normal faults and tilted fault blocks. The opening of the Suez rift resulted from the extension between the African and Arabian plates, leading to separation of the Arabian plate in the late Oligocene or Early Miocene [START_REF] Moustafa | Structural characteristics and tectonic evolution of the east-margin blocks of the Suez rift[END_REF]. The dip direction of the tilted blocks of the Suez rift changes from N-S to SW-NE and back to SE and implies the formation of three distinct provinces. These dip provinces represent three half grabens of opposite tilt directions [START_REF] Moustafa | Structural characteristics and tectonic evolution of the east-margin blocks of the Suez rift[END_REF], separated by two accumulation zones. The Suez rift faults extend into the Cairo-Suez fault systems but with smaller amounts of throw [START_REF] Moustafa | Transfer zones with en echelon faulting at the northern end of the Suez rift[END_REF].

3.3.e -The Dead Sea fault and Gulf of Aqaba fault system

The Dead Sea Fault (DSF, Fig. 14) is a boundary between the Sinai microplate and the northwestern part of the Arabian plate (Garfunkal et al., 1981). It consists of a narrow belt of NNE oriented, left lateral strike-slip faults which include the Gulf of Aqaba, the Dead Sea, and Lake Tiberias (Youssef, 1968). The Dead Sea deformation zone along the Dead Sea fault is about 45 km wide, while the DSF extends for about 1000 km from the Gulf of Aqaba to the Antachia triple junction (south Turkey; [START_REF] Mahmoud | Kinematic study at the junction of the East Anatolian fault and the Dead Sea fault from GPS measurements[END_REF].

In the Sinai region, the Gulf of Aqaba constitutes the eastern branch of the Red Sea, which is about 180 km long and 25 km wide, south of the DSF or Levant fault [START_REF] Hartman | Quaternary tectonic evolution of the Northern Gulf of Elat/Aqaba along the Dead Sea Transform[END_REF]. The Gulf of Aqaba appears as a succession of pull-apart basins bounded to the east by the Hejaz Mountains (Saudi Arabia) and to the west by the Sinai Mountains (Egypt), which shows a large inherited system of faults mostly parallel to the Gulf [START_REF] Frieslander | The structure of the Dead Sea transform emphasizing the Arava, using new geophysical data[END_REF][START_REF] Brink | Magnetic character of a large continental transform: An aeromagnetic survey of the Dead Sea Fault[END_REF]).

The pull-apart tectonic model of the Gulf includes the Eilat, Aragonese and the Dakar basins, respectively. These observations are results from the geological evidence and seismic reflections study of [START_REF] Hartman | Quaternary tectonic evolution of the Northern Gulf of Elat/Aqaba along the Dead Sea Transform[END_REF].

Seismicity and active tectonic zones

Historical earthquakes

The historical earthquakes in northeast Egypt and the Eastern Mediterranean, which occurred in the period from 2200 BC till 1899 AD are compiled by Maamoun et al.(1984) and [START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF]. We have analyzed the seismological literature, which covers about four thousand years of seismic history of northern Egypt and the eastern basin of the Mediterranean, through the catalogues of (Guidoboni and Comastri, 2005;Guidoboni et al., 2009 andAmbraseys, 2009).

Catalogues of (Maamoun et al., 1984;[START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF] From the historical documents dealing with earthquakes, it can be concluded that Egypt is one of the few regions of the world where evidence of historical earthquake activity has been recorded during the past 4200 years. Most of this information about historical earthquakes that have been felt in Egypt was collected from the annals of ancient Egyptian history, Arabic and European literature culturally flourishing (Badway et al., 1999).

Therefore, the nature and type of the documentary sources in which its history was preserved are essential.

The historical earthquakes of Egypt were collected during the period from 2200 BC to 1899 AD (Fig. 15 and see the Table 13 of the historical earthquakes in Appendix A). The most significant earthquake damage in the Eastern Mediterranean and in northern Egypt are described briefly in the following lines:

A -320 AD event

The epicentre is located in the Egyptian continental margin as shown in Fig. 15. It is, therefore, more likely that it is coming from an offshore earthquake near Alexandria. The 320 AD event damaged many houses in Alexandria and many people were injured (Ambraseys et al., 1994).

B -956 AD event

The event was felt with maximum intensity of VI based on the MSK scale in Alexandria city and caused the collapse of the upper 22-meter part of the lighthouse [START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF]. The 320 and 956 events occurred north of the epicentre of the September 12, 1955 (Ms = 6.8) earthquake. There are large events that cannot be distinguished clearly in the period before 1900 due to the variability in the felt effects from event to event.

C -The 21 July 365 event

The quake was located west of Crete at the plate boundary of the Hellenic Arc and quickly sent a wall of water across the Mediterranean Sea toward the Egyptian Coast (Fig. 15, [START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF][START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF][START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF]Shaw et al., 2008).The 365 9 m uplift in western Crete. It was probably responsible for the reported or observed destruction in ancient towns of West Cyprus and Libya. Historical and archaeological data also support the hypothesis that the fourth to the sixth centuries AD was a period of clustering seismicity in the Eastern Mediterranean region [START_REF] Pirazzoli | Earthquake clustering in the East-ern Mediterranean during historical times[END_REF].

The fact that the AD 365 coseismic uplift occurred in a single movement suggests the occurrence of an extensive seismic sea wave that can be modelled according to the inferred fault parameters (Stiros and Drakos, 2006;Shaw et al., 2008). On the Nile Delta, the sea wave caused temporary changes in the coastline, and in the region of Al-Manazala, east of Nile Delta between Damietta and Port Said, the previously rich land became a desert, presumably due to flooding (Ambraseys, 2009).

D -The 8 August 1303 event

The epicenter of the 8 August 1303 event is located in the Eastern part of the Hellenic arc as shown in (Fig. 15, Guidoboni and Comastri, 2005;Ambraseys, 2009).

According to Ambraseys (2009), this major earthquake caused serious damage in Crete, Rhodes, including other eastern Mediterranean coastlines in Cyprus, Palestine and Egypt.

In Egypt, the damage occurred at Abyar, Damanhur, al Wahsh and Sakha in the Nile Delta; in Alexandria, part of the city walls collapsed and the famous light houses were destroyed (Abu-El Fida, 1329). In southern Egypt, houses collapsed at Al-Minya (historical reports in Ambraseys et al. ( 2009)). In Cairo (which is ~150 km south of the Mediterranean coastline), ground movements were slow (probably due to surface waves), making it difficult for people to walk, while those on horseback were thrown down (historical reports in Ambraseys et al.(2009)).

Many houses suffered some damage and local contemporaneous witnesses report that the earthquake caused panic and women ran into streets without their veils (Ambraseys, 2009). Streets littered with fallen parapets and free standings walls slowed down the evacuation of the city, whose inhabitants encamped that night outside Cairo. The mosques of Al-Azhar, Al-Hakim and Amr Ibn-al-Ass at Fustat partly collapsed and had to be pulled down and rebuilt.

E -The 24 June 1870 event

Three shocks were noted in Alexandria at 18 h 25 which seemed to be directed from south-east to northwest and were accompanied by a hollow rumble (Soloviev et al., 2000).Three shocks, each about 5s long, were also felt in Ismailia at 18 h 25. These events were also felt in Cairo approximately at 18 h 30. The first one was very weak and only a few inhabitants noticed it. Two minutes later, a very strong shock occurred, and the third one that caused panic, came immediately (few seconds) after. The two main shocks were also felt in Beirut and Naplus at 18 h with an interval of 5 min and it was recorded in the earliest recording at the Observatory of Naplus (Ambraseys, 2009); the second shock was stronger than the first one. The second earthquake was felt in the vicinity of Beirut, in the town of Zebdani and in the Anti-liban range at 18 h 15 m and on the eastern shore of the Red Sea (Soloviev et al., 2000). The strong shocks were felt in the sea and in the ports and ships sustained severe damage. 13 of the historical earthquakes in Appendix A).

Instrumental Seismicity

The seismicity of Egypt was studied by many authors e.g., (Sieberg, 1932;Ismail 1960;[START_REF] Gergawi | Seismicity of Egypt[END_REF]Maamoun et al. 1984;[START_REF] Kebeasy | Seismicity[END_REF][START_REF] Ambraseys | The seismicity of Egypt, Arabia and the Red Sea: a historical review[END_REF]Abou Elenean, 1997). In their studies, the seismotectonic characteristics were addressed based on the regional geological structures and sometimes implying the dominant tectonic stress.

In 1997, the Egyptian National Seismological Network (ENSN) project started to cover all Egyptian territory (Fig. 16). The installation of new stations (ENSN) network has significantly enhanced the old seismicity distribution of the Egyptian region and the Red Sea.

The The most recent instrumentally recorded earthquakes with severe damage in northern Egypt are described briefly as follows Table 2; Maamoun et al. (1984); [START_REF] Hussein | Earthquake activities in Egypt and adjacent regions and its relation to geotectonic features in A[END_REF]: a-The September 12, 1955, Alexandria earthquake (Ms = 6.7)

It occurred offshore in the Egyptian continental margin at 06:09 (GMT). It was strongly felt in Egypt and causing large amounts of damage between Alexandria and Nile Delta. The epicenter was located about 120 km NW of Alexandria (Maamoun et al., 1984).

Eighteen people were killed, 89 injured, 40 houses collapsed completely and 420 houses ruined.

b-The March 31, 1969, Shadwan Earthquake (Mb = 6.1)

It occurred in Shadwan Island, the Red Sea at 07:15 (GMT) with Ms= 6.8 (Abu Elenean, 2007). The effect of this earthquake on the island caused fissures and cracks in the area south of Shadwan and extend a few kilometres towards the North (Saker et al., 2011).The main direction of this fault is an NW-SE direction, the same orientation of the Gulf of Suez. The coral reefs in the Red Sea appeared a few meters above the sea level after the earthquake, probably due to the uplifted sea floor. In Sharm El Sheikh and Hurghada cities, people ran outdoors, although had difficulty balancing and some mud brick houses were damaged in Ras Ghareb city (130 km north of Shadwan Islands). In the Nile Delta area, the event was very slightly felt at Kefrel Sheikh, Dakhalyia, Domiatta, Alexandria and the effects were stronger in the upper stories of the building (Maamoun et al., 1984).

c-The October 12, 1992, Cairo (Dahshour) earthquake (Mb = 5.8)

The earthquake epicenter was located at coordinates of 29.75°N and 31.13°E, at the outskirts of Dahshour village (SW Cairo, Fig. 17). The event affected Cairo and the northern part of the Nile Valley and caused much damage. Being close to the Cairo urban area, this earthquake was one of the single most expensive natural disasters in the history of Egypt. It was felt all over Egypt from Alexandria to Aswan (Hussein et al.,1996); also discussed by Abd [START_REF] El-Aal | Simulating time-histories and pseudo-spectral accerela-tions from the 1992 Cairo earthquake at the proposed El-Fayoum New City site, Egypt[END_REF]. It was estimated that about 8300 dwellings were destroyed, 561 people were killed, and 6500 were injured. An official investigation revealed that 1343 schools were damaged beyond any repair, 2544 need major repair and 2248 need maintenance-type repairs [START_REF] Khater | Reconnaissance report on the Cairo, Egypt Earthquake of October 12[END_REF][START_REF] Thenhaus | Reconnaissance report on the 12 October 1992 Dahshour, Egypt, Earth-quake[END_REF].

Tectonically, the faults of this area are trending E-W to NW-SE parallel to the Tethyan trend, or NW-SE parallel to the Gulf of Suez trend (Mesherf, 1990). It occurred in the Gulf of Aqaba and at least 8 people were killed and 30 were injured in the epicenter area. The earthquake occurred along the Dead Sea transform (DST)

fault system; the epicenter was located 60 km south of the Gulf of Aqaba. The heaviest damage occurred in the town of Eilat where seven hotels and 50 buildings were damaged. In Saudi Arabia, two people died and five others died in Egypt, three of them in the town of Nuweiba.

Active tectonic zones

Many attempts were made to partition Egypt into different seismotectonic zones and structural trends (Youssef, 1968;[START_REF] Maamoun | Tectonic acti vity in Egypt as indicated by eart hquakes[END_REF]Ibrahim and Marzouk, 1979;Maamoun et al. 1984;Kebeasy et al. 1987;[START_REF] Kebeasy | Seismicity[END_REF]Abu Elenean, 1997). The layout of these studies is made on basis of all available geology, geomorphology, geophysical, tectonic history, tectonic structures and seismicity.

In this study and on the basis of instrumental and historical earthquake catalogue, surface faults, tectonic and geological setting, and earthquake focal mechanisms of northeast Egypt, Six seismotectonic (Fig. 17

Focal mechanisms data

Earthquake source mechanisms are of prime importance in monitoring local, regional and global seismicity.

Our continental margin (see Tables 2,4,6,8,10,12 in Appendix A). The results are the focal mechanism solutions based on the polarity of the first P-wave motion e.g. [START_REF] Maamoun | La seismicite du Moyen et du proche-orient dans le cadre de la seismotectonique mondiale[END_REF][START_REF] Hussein | Earthquake activities in Egypt and adjacent regions and its relation to geotectonic features in A[END_REF]Hussein, & 1999;;[START_REF] Megahed | The Isamailyia (Egypt) earthquake of January 2 nd , location, macroseismic survey, radiation pattern of the first motion and its tectonics[END_REF]Badawy and Horvath, 1999;Abdel Fattah, 1999;Abou Elenean, 1997;Hussein and Korrat, 2001;Salamon et al., 2003;Hofstetter et al., 2003;Abou Elenean et al. 2004;Egyptian National Seismological Network (ENSN), 19982004) and solutions based on the waveform inversion (Hussein, 1999;Abou Elenean et al. 2004;[START_REF] Fattah | Another look at the 1993 and 1995 Gulf of Aqaba earthquake from the analysis of teleseismic waveforms[END_REF].

In addition to the available first motion solutions, the solutions of the global catalogues of CMT Harvard and the National Earthquake Information Center NEIC, as well as the regional CMT catalogues (RCMT) in the Mediterranean Sea region, are also In front of the Nile Delta, the continental slope shows a fairly well-developed stratification with many closely spaced normal faults. In principle, the continental margin can be considered a zone of weakness which experienced thinning of the crust during the Triassic period (Sofratome, 1984). This zone of transition between the faulted continental crusts and oceanic domain might be predestined by its orientation to be reactivated with dextral strike-slip and reverse components (Sofratome, 1984). reference Tables 1 and2 of focal mechanism solutions in Appendix A).

3.5.b. Dahshour zone

This zone is located in the northern part of the Western Desert and in the west of the Cairo Suez zone.

The epicenter of 19 collected focal solutions with M L previous work (Fig. 19; see Appendix A, Tables 3 and4) which are situated at the unstable shelf [START_REF] Said | Tectonic framework of Egypt[END_REF] underlain by high basement relief due to block fault and effect of minor compressional folding. The largest event in the Dahshour zone with M L 5.9 is the famous October 10, 2017event: black beach ball in Fig. 19. This event shows normal faulting mechanisms and its nodal planes trending NW-SE with some strike-slip component [START_REF] Maamoun | Detailed Studies of 12 October, 1992 Earthquake[END_REF]Hussein, 1999).

Most studied events indicate normal faulting with two nodal planes E-W to WNW-WSE in agreement with normal faults observed in the tectonic and geological map as shown in Fig. 11. 2 and4 in Appendix A).

3.5.c. Cairo Suez zone

Twelve focal solutions of earthquakes with M L work (Fig. 20, see Appendix A Tables 5 and6). This zone extends between the northern end of Suez rift to the Nile Valley in the northern Eastern Desert. The structural framework is dominated by two main sets of faults oriented E-W and NW that have the same age (see tectonic and geological map Fig. 12).

The mechanisms of large two events of September 29,1984 andApril 29, 1974 5 and6 in Appendix A).

3.5.d. Northern Gulf of Suez zone

The Gulf of Suez is a Neogene continental rift which has evolved as one arm of the Sinai triple junction together with the Gulf of Aqaba and the Red Sea. Although there are no significant earthquakes in the northern Gulf of Suez, it can be considered as one of the active seismic zones (Dagett et al., 1986). The 15 collected focal solutions of earthquakes with M L uez are shown in Fig. 21 (see Appendix A, Tables 9 and10). 11 and12).

The majority of solutions indicates predominate NW-SE trending normal faulting with strike-slip. They reflect normal faulting mechanisms with some strike-slip component and their nodal planes trending parallel to the main trend of the Gulf of Suez. 11 and12 in Appendix A for focal mechanism solution).

3.5.f. Gulf of Aqaba

The Gulf of Aqaba is a source region of intense activity which forms the main tectonic plate boundary between Africa (Sinai) and Arabia. The movement along this transform boundary caused some significant historical and instrumental earthquakes (Ambraseys, 2009). The largest recorded and strongest earthquake (Mw = 7. 7 and8). These mechanisms are consistent with the extensional regime of rhomb-shape grabens within the Gulf, and with the NNE-SSW trend of the aftershocks of the August 1993 earthquake (Abdel- [START_REF] Abdel-Fattah | Normal faulting mechanisms in the Western Desert of Egypt[END_REF].

The epicenters of 3 (see reference Table 8 in

Stress inversions

Many researchers have attempted to estimate regional stresses using a wide variety of direct inversion, iterative and grid search methods adapted for the reconstruction of past and present stresses from fault kinematics and/or earthquake focal mechanisms data e.g. [START_REF] Angelier | Tectonic analysis of fault slip data sets[END_REF][START_REF] Reches | Faulting of rocks in three-dimensional strain fields[END_REF]Vasseur et al., 1983;Gephart and Forsyth 1984;[START_REF] Carey-Gailhardis | A numerical method for determining the state of stress using focal mechanisms of earthquake populations: application to Tibetan teleseisms and micro seismicity of southern Peru[END_REF].

In this study, the inversion method of [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF] and Delvaux and Barth, (2010) is used for evaluating the stress field parameters in northern Egypt, using focal mechanisms of earthquakes collected from different sources as mentioned above. The inversion of fault-slip data gives the four parameters of the reduced stress tensor: the --ditional parameters of the full stress tensor are the ratio of extreme principal stress magnitudes however, these two parameters cannot be determined from fault data only.

We refer to [START_REF] Angelier | From orientation to magnitudes in paleostress determinations using fault slip data[END_REF][START_REF] Angelier | Inversion directe de recherche 4-D: comparaison physique et mathématique de deux méthodes de détermination des tenseurs des paléocontraintes en tectonique de failles[END_REF]Angelier ( , 1994) ) Thus, the corresponding misfit function to be minimized for each earthquake i is the Within the WinTensor software, we process the data using the Right Dihedron are independent of the choice of the nodal plane [START_REF] Angelier | Tectonic analysis of fault slip data sets[END_REF]. The initial result is used as a starting point for i misfit function F5 in the Tensor program.

In the following paragraphs, we will apply the stress inversions in the Egyptian continental margin and northern Egypt seismic zones (summarized in The stress tensor inversion is applied to 10 focal mechanisms events from Trend A (Table 3, 3). 3).

3.6.b. The Dahshour Zone (Zone B)

This zone acts as the source of the October 12, 1992 (Mw = 5.8) event, the most recent damaging earthquake in Egypt. This event provides key earthquake parameters for the study of active tectonics in the Dahshour area (Hussein, 1999). Two main fault trends WNW-ESE to E-W and NW-SE dominate in this area [START_REF] Sehim | Proposed structural model, Khalada West Concession, Western Desert, Egypt[END_REF]Mesherf 1990;Maaamoun et al., 1993). The stress tensor inversions were applied to 17 focal mechanisms of the Dahshour zone (Table 3,

c. The Cairo Suez zone (Zone C)

The dominant structural trend in this zone consists of two main sets of faults oriented E-W and NW with the same age [START_REF] Said | Tectonic framework of Egypt[END_REF]. The stress tensor inversions are applied to 18 focal mechanisms events for Cairo-Suez zone (Table 3, 3). 3).

3.6.d.Northern Gulf of Suez zone (Zone D)

The stress tensor inversions were applied to 14 focal mechanisms events for the northern Gulf of Suez (Table 3, 3).

3.6.e.South Gulf of Suez zone ( Zone E)

The stress tensor inversions were applied to 28 focal mechanisms of the south of the Gulf of Suez zone (Table 3, 3).

3.5.5.e. Gulf of Aqaba subzone (subzone F)

The dominated structural trend in Gulf of Aqaba transform fault is a left-lateral strike slip movement with major normal component [START_REF] Garfunkel | Internal structure of the Dead Sea leaky trans-form (rift) in relation to plate kinematics[END_REF]. The main structural trends of Gulf of Aqaba are N-S to NNE-SSW and NW-SE fault zone [START_REF] Ben-Avraham | Structural framework of the gulf of Elat (Aqaba), northern Red Sea[END_REF]Abdel Fattah et al., 1997).

The stress tensor inversions were applied to seven focal mechanisms events for the Gulf of Aqaba subzone F (Table 3, Fig. 30). This zone is located north of 29° latitude. The inversion of focal mechanisms in this zone yields an extensional regime, with the stress 0.89, N72.3ºE Sh-min and the rotational optimization of actual fault shows Tensor quality index A.

f. Gulf of Aqaba subzone (subzone G)

This subzone is located to the south of 29° latitude, where the stress tensor inversions are applied to 27 focal mechanisms of Gulf of Aqaba subzone G (Table 3, Fig. Gulf of Aqaba, subzone F (see Table 3). Gulf of Aqaba, subzone G (see Table 3).

Stresses field pattern and GPS results

The present-day tectonics is related to the collision of the African and Eurasian plates, in some regions with the Arabian-Eurasian convergence and displacement of the Anatolian-Aegean sub-plate. The boundary between the African and the Anatolian-Aegean sub-plate is delineated by the Hellenic arc, the Pliny Strabo trench, the Florence and Cyprus trench in the west [START_REF] Aksu | Miocene to Recent tectonic evolution of the Eastern Mediterranean: new pieces of the old Mediterranean puzzle[END_REF]. The subduction zone between Nubia and Eurasia and activities along the Red Sea, Gulf of Suez and Gulf of Aqaba may control the surface deformation in the north-eastern corner of the African continent.

Furthermore, the boundary between the Arabian plate and the Anatolian plate is characterized by predominantly left-lateral strike-slip motion with contraction and convergence and possibly in some regions a small amount of extension [START_REF] Mahmoud | Kinematic study at the junction of the East Anatolian fault and the Dead Sea fault from GPS measurements[END_REF]. These kinematic results explain the tectonic mechanisms linked with the present-day westward motion and counter-clockwise rotation of the Anatolian plate [START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF]. The increasing rate of motion toward the Hellenic and Cyprus trenches, suggests to us that the primary forces responsible for the westward motion of Anatolia, and perhaps a counter-clockwise rotation of Arabia, are associated with slab rollback along the Hellenic and Cyprus trenches [START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF]. Counter-clockwise rotation of the Arabian plate, with respect to the Anatolian block, may also be enhanced by slab pull from the NEdirected subduction beneath the Makran and possibly the south Zagros [START_REF] Bellahsen | Why did Arabia separate from Africa? Insights from 3-D labora-tory experiments[END_REF]. A direct corollary of this proposed dynamic hypothesis is that rifting in the Red Sea and the Gulf of Aden is a response to plate motions induced by the active subduction. This interpretation implies that continuing subduction of the African and Arabian oceanic lithosphere (i.e., Neotethys), is driving the plate motions and interplate deformation throughout the zone of interaction between the African, Arabian, and Eurasian plates. Along the transition zone between the northern Egypt continental and oceanic crust, the stress field changed from a dominate tension to a prevailing compression linked to the N-S compression of the Mediterranean convergence zone as manifested in several studies (Abou Elenean and Hussein, 2007;Bathworth, 2008). The Egyptian continental margin is the zone of transition between the faulted continental crust that might be predetermined by its orientation to be reactivated with dextral strike-slip and reverse components (Sofratome, 1984). The Cyprian and Hellenic arcs are dominated by compression, whereas to the east of Cyprus, a left-lateral motion exists [START_REF] Mahmoud | Kinematic study at the junction of the East Anatolian fault and the Dead Sea fault from GPS measurements[END_REF]. (http://www.world-stress-map.org/) and the GPS velocity vectors after [START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF]. The largest magnitude reported in earthquake catalogues for the Hellenic Arc is Mw 8.3 8.5 and refers to the July 21, 365 earthquake (Stiros and Drakos, 2006;Shaw et al., 2008). The hypocenter of this earthquake was probably located offshore of western Crete, along with a major thrust fault parallel to the Western Hellenic trench. The earthquake generated a large coseismic uplift and tsunami that was very likely destructive along the western Crete coast and is known to have destroyed most of the harbours and the Nile Delta area along the Egyptian coastline [START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF]Stiros and Papageorgiou, 2001;Dominey Howes, 2000;[START_REF] Papadopoulos | Tsunami hazards in the Eastern Mediterranean: strong earthquakes and tsunamis in the East Hellenic Arc and Trench system[END_REF]. The second large paleotsunami event generated by an earthquake source in the Eastern segment of the Hellenic Arc area is that of August 8, 1303, event. The estimated magnitude of this earthquake is 8.0 [START_REF] Papazachos | Large seismic faults in the Hellenic arc[END_REF]. The Cyprian Arc is the third tsunamigenic source, which is the closest subduction zone to the Egyptian-Mediterranean coast but is smaller and less active than the Hellenic Arc. The largest magnitude reported in the earthquake catalogues for Cyprus is 7.5, from the May 11, 1222 earthquake.

The continental margin of Egypt is considered to have no potential for tsunamigenic earthquakes. Large earthquakes (with M>6) or landslides that produce local tsunamis also originate from time to time from the Egyptian coast, but no significant basin-wide tsunami is known to have originated from this region. Although M 6.5 earthquakes such as the offshore Ms 6.7 Alexandria earthquake on September 12, 1955, have already occurred in the continental margin (Korrat et al., 2005). It was close to the sedimentary cone of the Nile that poses the potential for tsunamis [START_REF] Garziglia | Mass transport deposits on the Rosetta province (northwest Nile deep-sea turbidite system, Egyptian mar-gin): characteristics, distribution and potential causal processes[END_REF].

In this Chapter, I will present the significant historical tsunamis that affected northern Egypt and the East Mediterranean region, the paleotsunami research study conducted along the Egyptian coastline by means of trenching and coring at EL Alamein and Kefr Saber sites. The study includes the description of cores and trenching at both sites, the analysis and interpretation of geochemical and magnetic susceptibility measurements with the chronology of events using C 14 dating of the coastal sedimentary layers.

Historical paleotsunamis of northern Egypt:

Large earthquakes caused most of the historical tsunamis in the Mediterranean region. Although, there is a low possibility of landslide tsunamis occurring offshore of the Nile Delta due to the high slope of the continental margin. Yalciner, (2014) estimated a landslide volume of 500 km 3 , which may trigger a tsunami with wave height ranging from 0.4 to 4 m, that would affect major cities of the northern coast of Egypt (Alexandria, Damietta, Port Said). The recent example of landslide tsunamis in the Mediterranean was associated with the eruption of Stromboli volcanic, December 30, 2002[START_REF] Tinti | The 30 December 2002 landslide-induced tsunamis in Stromboli: sequence of the events reconstructed from the eyewitness accounts[END_REF].

The preserved historical documents and archives are the principal sources of macro seismic data for historical earthquakes and tsunamis. Since the beginning of the 20th century, much effort has been undertaken towards the establishment of a reliable catalogue of historical seismicity based on the retrieval and assessment of original sources of information e.g. (Poirier & Taher, 1980 ;Maamoun, 1984 ;Soloviev et al. 2000 ;Ambraseys, 2009 ;Guidoboni, 2009). [START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF] and Ambraseys (2009) report several large earthquakes with tsunamis that caused damage in the eastern Mediterranean region and in particular in the coastal metropolises of Egypt (Table 4). Among these events, the tsunamis of 21 July 365, 8

August 1303 and 24 June 1870, local and contemporaneous reports describe wave heights with inundations and severe damage to the city of Alexandria as well as the Mediterranean coast of Greece, Sicily, Libya, Cyprus, Syria, Lebanon and Palestine. The three events were most likely triggered by major earthquakes in the Hellenic subduction zone (Papadopoulos et al., 2014).

Table 4: Historical earthquakes and tsunamis effect on the north Egyptian coast

The following is a short description of the three most significant tsunamis triggered by large earthquakes that affected northern Egypt :

a-The 365 tsunamigenic event Historian Ammianus Marcellinus in [START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF] a Roman historian who lived in the fourth century (325 391 AD), reported the tsunami event 13 years after in 378 AD. He documented the devastating effects of the tsunami hitting Alexandria with comments such as " away The waters returning when least expected killed many thousands by drowning perched settlements around the Mediterranean were hit at roughly the same time.

Reports indicate that ships in the harbour of Alexandria were overturned as the water near the coast receded suddenly and that many people rushed out to loot the hapless ships.

The tsunami wave then rushed in and carried the ships over the sea walls, landing many on top of buildings. In Alexandria, approximately 5,000 people lost their lives and 50,000 homes were destroyed. The surrounding villages and towns suffered even greater destruction and many were virtually wiped off the map. Outside the city, 45,000 people were killed. In addition, the inundation of salt water rendered farmland useless for years to come. Slowly, but steadily, the buildings of Alexandria's Royal Quarter were overtaken by the sea following the tsunami. It was not until 1995 that archaeologists discovered the ruins of the old city off the coast of present-day Alexandria.

A review of historical accounts [START_REF] Hamouda | Tsunami data base of the Eastern Mediterranean[END_REF]Ambraseys, 2009) of a notable earthquake, such as that of 21 July AD 365 indicates that this event destroyed nearly all towns in Crete and was followed by a tsunami, which had devastating effects on coastal areas of the eastern Mediterranean.

The study of paleo-shorelines that fringes the coast of western Crete and to 10m above present sea level in southwest Crete. Because these marks run through the remains of a Roman harbour at Phalasarna at 6m above sea level, he deduced that the land must have been raised during or after the Roman era. [START_REF] Pirazzoli | Historical envi-ronmental changes at Phalasarna harbour,West Crete[END_REF] showed that this shoreline that extends in all western Crete had a C 14 age of around 2,000 yr BP and attributed its uplift to an earthquake; this earthquake was subsequently linked to the AD 365 event. [START_REF] Pirazzoli | Historical envi-ronmental changes at Phalasarna harbour,West Crete[END_REF] also indicate the existence of small subsidence events in between large uplifts. Shaw et al., (2008), using radiocarbon dates, refer to the uplift of western Crete in AD 365 but with an age uncertainty. The field observations also show slow uplift during short intervals in a series of rapid small events. The authors inferred that either uplift of western Crete and its surrounding sea floor took place slowly within a few decades of AD 365 and some other event caused the tsunami that destroyed Alexandria in AD 365, or the two events are connected. Shaw et al., (2008) also model the tsunami wave propagation across the eastern Mediterranean and infer the occurrence of 0.6 m wave heights reaching the Egyptian coast.

b-The 1303 tsunamigenic event

On 8 August 1303, a major earthquake with magnitude ~Mw 8 occurred in between Crete and Rhodos islands and generated a tsunami that greatly damaged the coastal cities of eastern Mediterranean, in particular, the cities of Candia and Heraklion (Crete), and Alexandria with the Nile delta was flooded (Ambraseys, 2009 ;Papadopoulos et al., 2014).

In Greece, it resulted in destruction in the islands of Rhodos, Crete and the Peloponnesus.

According to detailed contemporaneous reports, many houses were damaged in Cairo and northern Egypt, ships were torn apart and many of them were carried inland due to tsunami waves (the detailed description of this earthquake and its effect in Egypt is in the contemporaneous Arabic source of Abu-El Fida born 1273 died 1331 ( 1329)).In Alexandria, the sea spilt over into the harbour, inundating the shore, carrying sailing ships and boats onto the land and with the fall of Alexandria lighthouse. Houses were ruined and 70 m of the city wall together with 27 towers were destroyed. However, Abu-El Fida report that the worst damage was caused by the combination of the earthquake, the sea and high winds, which drove ships onto the coast and demolished part of the ramparts, killing 46 people.

c-The 24 June 1870 tsunamigenic event:

A large earthquake was felt throughout the eastern Mediterranean followed by tsunami waves on Alexandria. It is reported that the location of this earthquake is probably either the Eastern Hellenic arc (i.e., the same location as of 8 August 1303 earthquake) or the May 11, 1222 earthquake in the Cyprian Arc. In Alexandria, three successive shocks were felt with no earthquake damage. Everyone along the coast of Nile Delta felt the earthquake and it was reported from Port Said to Suez Canal. In the new Port area, the sea flooded the quay and the shock was felt on board ships in both the old and new ports.

The strong shocks were felt in the sea and in the port where ships also underwent severe shocks. The three shocks lasted for about 5s each were also felt in Ismailia at 18 h 25m, but they were very strong. The three shocks also occurred in Cairo at approximately 18 h 30 m. The water in the new port of Alexandria splashed out onto the quays.

Paleotsunami investigations

The paleotsunami investigations are classified into fieldwork and laboratory analysis.

Three successive field campaigns were carried out in June 2014, August 2015, and October 2015. The aim of these field investigations was to choose the best locations that triggered tsunami deposits from geological and geomorphological evidence.

The work was carried out by trenching and coring in the two selected sites of Kefr Saber (Marsah Matrouh) and El Alamein (Fig. 33) and the sampling collection includes charcoal, gastropods, shells, roots samples in trenches and cores. In the laboratory, different core analyses were undertaken including collecting samples for dating after opening the cores, photography, detail stratigraphic descriptions, X-ray scanning, geochemical analysis, Magnetic susceptibility (methods are described in detail in Chapter II). Several criteria were applied to select the sites, taking into account geomorphological and topographic setting, accessibility in order to avoid urbanization and artificial soil reworking. The criteria are 1) the presence of large boulders; 2) sand dunes;

and 3) Lagoons environment and salt marshes. Two sites, 160 km apart, met the selection criteria for site investigation: 1) Kefr Saber, and 2) El Alamein site (Fig. 33). Saber and Ras El Hekma (Table 1 in Appendix E). Ras El Hekma. This surface is mostly covered with carbonate dunes (Fig. 38).

Fig. 38: Show lagoons behind the sand dunes.

4.3.b. Cores and trenching

Coring and trenching act as effective tools which allow us to recognise paleotsunami deposits and landforms, e.g. (De Martini et al., 2012 andMalik et al., 2015). In this study, trenching and cores were undertaken within the two selected studied areas along the northern coast of Egypt in Kefr Saber and EL Alamein sites. This was done in order to study the sedimentary succession and to identify the possible tsunami deposits and correlate them with historical tsunamis records.

Trenches, ~2 x 1 m and ~1.5 m deep, were dug in both selected sites. The underground water infiltration was treated using a water pump (Fig. 39).The cores (Fig. 40 and Fig. 41) were collected in both sites using a Cobra digging instrument. The tube's has a diameter of 2 inches and 1m long. The cores were taken up to depths of 2.6 m.

4.3.c. Laboratory analysis

The cores were then opened (Fig. 42) with a Fisher wire in the Laboratory of the National Institute of Geophysics and Astronomy (NRIAG), then labelled. The first half of the cores have been named and archived, while the other part was used for measurements and sampling.

X-ray radiographs were carried out on cores using medical X-ray scan laboratory before they were opened to identify the details of sediments and microfossils. Very intensive X-ray was used in order to penetrate the sediments to show the details in sediments. Three 40 cm-long x-ray pictures were taken for each 1 m long core with an overlap of least 5 cm.

The cores and trenches were described according to their length, colour, texture (grain-size, sorting), sedimentary structures (natural or due to coring disturbances), type of sedimentary contacts (sharp or gradient). The cores and trenches were then photographed using DSLR (Digital Single-Lens Reflex camera) in 25 cm long sections, with an overlap of at least 2 cm. These pictures were assembled together to reconstruct a single image for each core section.

A number of different measurements were taken from the cores (Fig. 43); the magnetic susceptibility was measured with 3 cm intervals along the cores using a Bartington MS-2 system. Samples with a dimension of 2 cm long were collected every 15 cm for bulk mineralogy, grain size, total organic and inorganic analysis which was carried out at the laboratory of a central metallurgical research institute (CMRDI) in Helwan. The radiocarbon dating of samples was carried out in three laboratories (Poznan laboratory -Poland, CIRAM in Bordeaux, France and Beta Analytical Laboratory, USA) to ensure consistent and high quality results (Table 1 and2 in Appendix E). The collected samples were made of charcoal, bones, gastropods, shells and organic matter. The radiocarbon dating results of charcoal and organic matter were calibrated using a recent calibration curve [START_REF] Reimer | Selection and treatment of data for radiocarbon calibration: an update to the International Calibration (IntCal) criteria[END_REF] and Oxcal software for the probability density function of each sample age with (Bronk- Ramsay, 2009); furthermore, the gastropods and shells were corrected against reservoir effects.

4.3.d. Trenching and coring description in the investigated sites

In the following, a description for trenching and coring in the two selected areas of Kefr Saber and El Alamein is presented, with the analysis procedures and interpretation performed along the northern coast of Egypt. The five trenches dug in Kefr Saber (Fig. 44c) were numbered according to the time they were dug. The following is the description of tsunami layers found in trenches located in Fig. 44 c:

Trench no.1
Located 152 m from the shoreline, this trench shows a succession of soft sedimentary layers made of sandy-silt, sandy-clay and fine gravel layers. A layer of mixed sand and gravel, and broken shells (Fig. 45) is found at 35 cm depth, but with a variable thickness from 2 to 10 cm in trench walls. This layer is characterized by rich broken shell fragments and is interpreted as of tsunami origin. Two samples of charcoal are chosen in Trench 1 at Kefr Saber for dating (Table 1 in Appendix E). The first is of modern age at 35 cm depth. The other charcoal sample is at 53 cm depth and aged between 39000-38250 BC.

This sample is found below the stratigraphic tsunami layer. This sample is transported from deepest sediments due to the high wave current tsunami. is below the tsunami layer 1 (Table 1 in Appendix E). The other charcoal sample is at 100 cm depth and has a date of 5300-5070 BC. This sample is transported from deepest sediments due to the high wave current tsunami. This layer is found at 55 cm depth in Trench 4 (Fig. 48) with lateral variation from 1 to 5 cm in thickness and is characterized by reworked shells and gastropods.

Five charcoal samples are chosen for dating in Trench 4. The first sample is at 15 cm depth and is from the modern age. The second sample is at 20 cm depth and has a date of 1700-1920 AD. The charcoal at 40 and 61 cm depth have a modern age and may be transported from shallow to deep depth due to a contamination of farming in this area. The last charcoal sample is at 60 cm depth and has a calibrated age of 17200-15900 BC (Table 1 in Appendix E). These samples are located within the tsunami deposits in Trench 4 and are transported from deepest sediments of high energy current waves during the tsunami of 21

July 365.

Trench no.5

This trench is located at 72 m from the shoreline is the closest to the sea (Fig. 44 c).

The mixed white sand with reworked fossils reached the maximum thickness near the shoreline and is found at a depth of 22 cm (Fig. 49). Two phases of boulder accumulation were found at depths of 25 and 40 cm. The first phase of the boulders has an angular surface, while the second phase of boulders and pebbles is more elliptical and smoothed.

Four charcoal samples are chosen for dating in Trench 5 (Table 1 in Appendix E). The first charcoal is found at 12 cm depth and has an age of 360-50 BC for the transported sediments.

The second sample is found at 17 cm depth with and age 30-180 AD. The third and fourth charcoal samples are found at depths of 33 and 37 cm and have calibrated dates of 350-1050 BC and 2400-4000BC, respectively. These last two samples, found in the thicker tsunami layer in Trench 5, resulted from transport due to high energy currents during tsunami waves. The first layer is at 12.5 cm depth with 34.5 cm thick, brown clay sediments with extremely poor sorting, fine grain sediments, with an observable peak in magnetic susceptibility, rich in organic matter, and the X-ray image reflects clear lamination.

The second layer at 70 cm depth is 5 cm thick. It is characterized by highly broken shell fragments with the extremely bad sorting of sediments. The third layer at 75 m depth is 22 cm thick as is a pale yellow sand with the extremely bad sorting of sediments, with an observable peak in magnetic susceptibility. The chemical analysis shows the presence of gypsum and minor goethite.

A possible fourth tsunami layer at 160 cm depth is a 20 cm thick, brown silty clay with extremely poor sorting, with a peak in magnetic susceptibility, rich in broken shell fragments and high organic matter.

Two samples are chosen for dating in core 1. The first charcoal sample is at a depth of 40 cm and has a calibrated date of 13985-14415 BC (

Core 2

As shown in Fig. 50 b, core 2 is 90 cm deep located south of core 1 at 264 m from the shoreline. Two tsunami layers are recognized as shown in (Fig. 53). The first tsunami layer, of brown clay sediments, is at 12.5 cm depth and is 12.5 cm thick with extremely bad sorting, corresponding to a small peak at magnetic susceptibility. The layer is rich in organic matter (> 1 weight %) compared with other layers of this core; the geochemical analysis shows minor component of goethite.

The second layer is at 50 cm depth and is 15 cm thick and is made of yellow sand with silty-clay pockets, rich with broken shell fragments, extremely poor sorting with peak magnetic susceptibility. It is rich in organic matter compared to other layers, and the geochemical analysis shows minor component of halite.

Two samples are chosen for dating in core 2. The two gastropod samples are at depths of 75 and 77 cm and have calibrated dates of 32971-34681 and 34362-36931 BC, respectively (Table 2 in Appendix E). These two samples are located at the bottom of tsunami stratigraphic layer 2. These samples are transported from the deepest sediments due to high current waves of the tsunami.

Core 3

This core is located 270 m from the shoreline and the outlet of sea water as shown in Fig. 50 b.

The first tsunami layer is at 25 cm depth and corresponds to a 26 cm thick pale brown clay with poorly sorted sediments. It is characterized by highly broken shell fragments and is rich in organic matter. The second layer, at 70 cm depth, is 17.5 cm thick and is characterized by white sand with laminations at the top and fine sediments at the bottom, with a peak of magnetic susceptibility near zero value, and with high organic matter > 2. The third tsunami layer at 106 cm depth is 32 cm thick, characterized by yellow sand with minor illite and broken shells fragments as shown in (Fig. 54).

Two samples are chosen for dating in core 3. The two shell samples are at depths of 37 and 45 cm and have calibrated dates of 43618 BC and 34218-37224 BC, respectively (Table 2 in Appendix E). These two samples are located in stratigraphic tsunami layer 2. These samples are transported from the deepest sediments due to high energy current waves of the tsunami.

Core 4

It is located 435 m from the shoreline. It characterized by two tsunami layers (Fig. 55). The first tsunami layer is white sand at 12.5 cm depth and is 7 cm thick with highly sorted sediments. It also shows highly broken shell fragments with organic matter > 2. The third tsunami layer is a 35 cm thick pale yellow sand at 102 cm depth. It is also characterized by yellow sand with a minor amount of illite and gypsum and broken shell fragments.

One sample is chosen for dating in core 4. The shell sample is at a depth of 37 cm and has a calibrated date of 32887-34447 BC (Table 2 AppendixE). This sample is located in stratigraphic tsunami layer 1. This sample is transported from the deepest sediments due to high energy current waves because of the tsunami.

Core 5

This is the southernmost core in the El Alamein site and is 490 m from the shoreline (Fig. 53 b). It does not contain any tsunami layers (Fig. 56). It may mean that core 5 fixes the limit of inundation in the area with respect to the first and second tsunami layers.

One sample is chosen for dating in core 5. The gastropod sample is at a depth of 50 cm and has a calibrated date of 442182-448237 BC (Table 2 in Appendix E). This sample is transported due to high current waves from the deepest sediments. and 3) and with laminations at 2 and high organic matter are interpreted as deposits of tsunami origin.

Core 6

This core is located south of the sand dunes, 320 m from the shoreline. It is characterized by three tsunami layers (Fig. 57). The first tsunami layer is a pale yellow sand with broken shell fragments at 5 m depth and is 24 cm thick with highly sorted sediments rich in an organic matter > 2.5. The second tsunami layer is at 58 cm depth and is 18.5 cm thick and is characterized by yellow sand with a minor amount of gypsum and Illite. The third tsunami layer at 130 cm depth is 20 cm thick and is characterized by white sand with a minor amount of goethite and broken shell fragments. It is very rich in the total weight of organic matter >3 weight %.

Three samples are chosen for dating in core 6. The first gastropod sample is at a depth of 45 cm and has a calibrated date of 35002-37441 BC. The second coral sample is at a depth of 60 cm and has a calibrated age of 42776-69225 BC. The third coral sample is at a depth of 80 cm and has a calibrated age of 1620AD (Table 2 in Appendix E). The first sample was above the stratigraphic tsunami layer 2 while the second sample was within the stratigraphic tsunami layer 2. These samples are transported due to high current waves of the tsunami.

The last sample may be transported due to old farming which occurs up to depths of 80 cm.

Core 7

This core was located 273 m from the shoreline. It characterized by three tsunami layers(Fig. 58). The first tsunami layer is a 6 cm thick brown sand with broken shell fragments at 14 cm depth with highly sorted sediments. It is characterized as being rich with organic matter > 2 and a noticeable peak of magnetic susceptibility and the presence of gypsum from the lagoonal environment and a minor amount of Illite and goethite. The second tsunami layer, at 50 cm depth, is a 20 cm thick layer characterized by pale brown clay with pebbles at the bottom. The third tsunami layer, at 115 cm depth, is a 15 cm thick layer characterized by white sand, bad sorting of sediments with a minor amount of pyrite.

One sample is chosen for dating in core 7. The sample is at a depth 17 cm and has a calibrated date of 293-1113 BC.

Core 8

This core is located 214 m from the shoreline. Three tsunami layers are recognized as shown in (Fig. 59) in this core. The first tsunami layer is a pale silty clay at 14 cm depth and 16 cm thick with high organic matter and a minor amount of Goethite. It is characterized by highly broken shell fragments and is rich in organic matter. The second layer, at 52 cm depth, is 22 cm thick and is characterized by pale yellow silty-clay, with a low peak of magnetic susceptibility and high organic matter >2.5. The third tsunami layer at 128 cm depth is 9 cm thick and characterized by pale yellow sand with highly angular gravel sediments, badly sorted and broken shell fragments.

Core 9

It is located 130 m from the shoreline. Three tsunami layers are recognized within the core (Fig. 60). The first tsunami layer is a white sand at 16 cm depth. It is 13 cm thick, with high organic matter and rips up clasts that appear in X-ray scanning and characterized by highly broken shell fragments and is rich in organic matter. The second layer, at 67 cm depth, is 22 cm thick and is characterized by white sand, with a peak of the magnetic susceptibility high content of organic matter > 5. The third tsunami layer at 139 cm depth is 14 cm thick and is characterized by broken shell fragments and white sand with highly angular sediments that reflect the bad granulometric sorting.

Two samples are chosen for dating in core 9 (Table 1 in Appendix E). The first gastropod sample is at a depth of 24 cm and has a calibrated date of 1052-1888 BC. The second bivalve sample is at a depth of 55 cm and has a calibrated age of 40521-43169 BC. The first sample was found in the stratigraphic tsunami layer1 while the second sample was below the stratigraphic tsunami layer 1 and above stratigraphic tsunami layer 2. These samples are transported due to high current waves of the tsunami.

Core 10

It is located 245 m from the shoreline. Three tsunami layers are recognized (Fig. 61).

The first tsunami layer is a brown silty clay at 19 cm depth. It is 9 cm thick, with high organic matter and with rip up clasts and lamination that appear in X-ray scanning. It is characterized by highly broken shells fragments and is rich in an organic matter > 4. The second layer at 48 cm depth is 38 cm thick and is characterized by brown sand with broken fragments of shells, with a peak of magnetic susceptibility and high organic matter > 1.5 at the bottom of the layer. The third tsunami layer, at 101 cm depth, is 28 cm thick and characterized by pale yellow sand rich in organic matter and sediments that reflect the bad sorting.

Two samples are chosen for dating in core 10. The first shell sample is at a depth of 24 cm and has a calibrated date of 2623-3521 BC. The second bone sample is at a depth of 70 cm and has a calibrated age of 41256-46581 BC (Table 2 in Appendix E). The first sample was found in the stratigraphic tsunami layer 1 while the second sample was within stratigraphic tsunami layer 2. These samples are transported due to high current waves of a tsunami from the deepest sediments. The layers with high values of magnetic susceptibility (especially for 1, 2 and 3) and organic matter are interpreted as deposits of tsunami origin

Core 11

It is located 151 m from the shoreline. Three tsunami layers are recognized (Fig. 62).

The first tsunami layer is a white sand at 19 cm depth. It is 10 cm thick and characterized by highly broken shells fragments and rich in an organic matter > 4 with a high weight% of gypsum. The second layer at 76 cm depth is 9 cm thick and characterized by white sand, with broken fragments of shells, with a peak of magnetic susceptibility and high organic matter > 1.5. The third tsunami layer at 107 cm depth is 21 cm thick and is characterized by grey silt and sediments which reflect the bad sorting and high organic-rich matter with a minor amount of Illite and gypsum.

Eight samples are chosen for dating in core 11. The first gastropod sample is at a depth of 20 cm and has a calibrated date of 3638-4328 BC. The second shell sample is at a depth of 62 cm and has a calibrated date of 3710-3943 BC (Table 2 in Appendix E). These two samples are found in the stratigraphic tsunami layer 1 and 2, respectively. They are transported from the deepest sediments by high wave current of the tsunami.

The third gastropod sample is found at a depth of 116 cm and has a calibrated date of 2619-3386 BC. The fourth gastropod sample is found at a depth of 121 cm and has a calibrated date of 2457-3366 BC. The fifth gastropod sample is found at a depth of 126 cm and has a calibrated date of 2477-3368 BC. The sixth shell sample is found at a depth of 152 cm and has a calibrated date of 33294-36120 BC. The seventh root sample is found at a depth of 139 cm and has a calibrated age of 2666-2817 BC. The eighth charcoal sample is found at a depth of 180 cm and has a calibrated date of 3710-3943 BC (Table 2 in Appendix E). From the third to eighth samples, except the sixth sample, are arranged chronologically within the second meter in the core from 2457 to 3943 BC. The sixth sample seemed to be transported by high wave current of the tsunami.

Core 12

It is located 127 m from the shoreline. Four tsunami layers are recognized (Figs. 63 and64). The first layer is variable in thickness,but~7.5cmthick at ~19cmdepth. It is made of poorly sorted white sandy deposits, and highly broken gastropods and lamellibranch fossils.

This layer is characterized by a high value of organic matter and the high peak of magnetic susceptibility reflect rich carbonates. The second layer is ~13cm thick at ~32.5cmdepth and is characterized by white sandy deposits intercalated with coarse brown sand horizontal lamination, poorly sorted sediments, rich in total organic matter and the high peak of magnetic susceptibility. The third layer is ~25cmthick at 89cmdepth and is made of grey sandy clay, with laminations at the bottom of deposits, vertically aligned gastropods, broken shell fragments, rich in total organic matter and pyrite showing a high peak of magnetic susceptibility. The fourth tsunami layer is at 151 cm depth and is 17.5 cm thick. It is characterized by pale yellow medium to fine-grained sand with broken shell fragments and extremely poor sorting, with the high peak of magnetic susceptibility, the high peak of organic matter > 5.5 and high amount of gypsum.

Five samples are chosen for dating in core 12. The first gastropod sample is found at a depth of 44 cm and has a calibrated date of 3367-3366 BC. The second shell sample is found at a depth of 108 cm and has a calibrated age of 3097-3950 BC (Table 2 in Appendix E). The third gastropod sample is found at a depth of 114 cm and has a calibrated date of 3331-4050. The fourth shell sample is found at a depth of 117 cm and has a calibrated age of 39560-40811 BC. The fifth gastropod sample is found at a depth of 135 cm and has a calibrated age of 3365-4071 BC (Table 2 in Appendix E). The first and fourth samples seem to be transported from deep sediments due to high energy wave current. The other samples were found within the second meter of the core sediments and this coincides with the calibrated ages in core 11; as it indicates the second meter of the sediments belonged to 2457 to 4071 BC ages.

Fig. 62: Description of core no.11 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 151 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2) and organic matter are interpreted as deposits of tsunami origin Fig. 63 : Description of core no.12 section 1 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 151 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1, 2 and 3) and organic matter are interpreted as deposits of tsunami origin Fig. 64: Description of core no.12 section 2 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The fourth layer (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility and organic matter are interpreted as deposits of tsunami origin

The composite section and chronology sequence of the tsunami layers

The correlation between trenches and cores in both sites helps to construct two composite sections from both sites using the chorology from the dated samples. The stratigraphic position of the tsunami layers was identified in the sediments of cores and trenches based on the grain size, sedimentary structures and the nature of the contact (sharp or gradual), fossils content, and geochemical and magnetic susceptibility. The composite stratigraphic section of 1 m of sediments from trenches in Kefr Saber with chronology dating are summarized in Fig. 65 and the composite section for the cores in El Alamein are summarized in Fig. 66.

The sedimentary units in Kefr Saber trenches were identified as nine stratigraphic units (Fig. 65) in the composite section. The tsunami layers are characterized by stratigraphic signatures probably related to one tsunami. The tsunami layer is at a depth of ~35 cm with thickness varying along the trenches from 2 to 20 cm. The tsunami layer appears as a homogeneous white sandy layer that exists in trenches P1, P3 and P4 located in a middle of the lagoon. The tsunami deposits are composed of white sand with oolitic carbonate similar to the nearby sand dunes. The white sandy layer is rich in reworked fossils and broken shell fragments with a high percentage of carbonate.

The sedimentary units of the cores at El Alamein site were identified by 11 stratigraphic units in the composite section (Fig. 66). The first tsunami layer has an average thickness of7.5 cm and is found at a depth of 13.5 cm. It is made of poorly sorted white sandy deposits with highly broken gastropods and lamellibranch fossils. The observable peak in magnetic susceptibility is a low value close to zero which reflects a rich carbonate content in the tsunami layer. The X-rays correlation between cores shows laminations and rip up clast in this layer. The second tsunami layer is ~15cmthick and is 50 cm deep. It is characterized by white sandy deposits intercalated with coarse brown sand horizontal lamination, poor sorting sediments, rich in total organic matter and the high peak of magnetic susceptibility. The bottom of this layer is characterized by pebbles.This layer also shows inclined stratifications. The third tsunami layer is ~25 cm thick and the depth is 89 cm. It is made of grey sandy clay to pale yellow sand, with laminations at the bottom of deposits. We also observe vertical and horizontal gastropods direction, broken shell fragments, rich in total organic matter and pyrite and goethite, showing a high peak of magnetic susceptibility. The fourth tsunami layer has an average thickness of 20 cm and a depth which varies from 151 to 160 cm with highly poorly sorted sediments. It is also characterized by brown silty clay with broken shell fragments.

By dating the samples (see Table 1 and2

Conclusion and Summary of results:

The geomorphological landforms along the northern Egyptian coast are characterized by sand dunes, accumulation of large boulders, lagoons. The large accumulation of boulders extends along the Egyptian coast particularly in Ras EL Hekma and Kefr Saber which have boulders rich in Dendropoma species. Although the detailed study of boulders is not included in this study, two Dendropoma species were sampled (see The cores and trenches in both the Kefr Saber and Alamein sites were dug during three fieldworks to identify the tsunami deposits according to their interpreted sedimentary tsunami signatures (see details of trenches and cores above). The stratigraphic log of the trenches in Kefr Saber mainly show one tsunami layer of mixed sand and gravel, and broken shells at a depth of ~ 35 cm (see the composite section in Fig. 65). The cores in El Alamein show four main layers, characterized by fine and coarse sand mixed with broken shell fragments that indicate the occurrence of high energy sedimentary deposits in the coastal lagoon environment(see the composite section in Fig. 66). A remarkable observation is the similarity of the white layers of sand with broken shells observed in trenches and cores at both sites ~200 km apart. We interpret these as tsunami deposits due to their sedimentary signatures (see details of core descriptions above).

From the composite sections and dating chronology in Kefr Saber and El Alamein of Egypt correlate with historical earthquake records o that the tsunami deposits of the 365 AD tsunamigenic earthquake have a larger thickness at Kefr Saber site than at the El Alamein site. However, the opposite trend is seen for the 1303 AD and 1870 AD sedimentary layers which are thicker at the El Alamein site. These observations can be justified by the proximity of the tsunamigenic source in western Crete and 365 AD earthquake with respect to the Kefr Saber site, and the proximity of the 1303 AD and 1870 AD seismic sources in the east Hellenic Arc with regards to the El Alamein site.

Chapter V

Tsunami modelling and scenarios in the northern Egypt

Introduction

The analysis of tsunami scenarios is a very useful approach for the evaluation of tsunami hazard and risk for any given region. It is the first step in the frame of tsunami mitigation and preparedness for a sustainable coastal zone development. Few countries around the world took serious notice of tsunamis until the occurrence of the Indian Ocean tsunami following the Mw 9.1 earthquake of December 26, 2004, in Sumatra (Indonesia).

The massive tsunami generated by the Great Tohoku earthquake Mw 9 in East Japan on 11

March 2011 had a maximum wave height that reached to 19.5 m at Sendai Plain [START_REF] Mori | Survey of 2011 Tohoku earthquake tsunami inundation and run-up[END_REF] and impacted a 2000km stretch of the Pacific coast of eastern Japan. The tsunami propagated more than 5km inland.

These significant events around the world brought the problem of tsunami hazard and risk assessment to the attention of the scientific community and showed the urgent need for tsunami hazard assessment for other seismogenic regions. The assessment is important for the Eastern-Mediterranean countries that are known to have been affected by earthquakes, volcanic eruption or landslides and related tsunamis events throughout history. The aim of this chapter is to develop two simple scenarios for the main far field tsunami-genic in the eastern and western Hellenic arcs which have geological records in this study. we test five scenarios of eastern Hellenic arc and five scenarios of western Hellenic arcs using different focal mechanisms of large recent earthquakes of the same historical location information of the 21 July 365 and 8 August 1303 [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF]Guidoboni and Comastri, 2005) and we used the calculated fault ruptures of eastern Hellenic arc [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF] and for eastern Hellenic arc (Pagnoni et al., 2015). The magnitude of the earthquakes were enlarged to be equal or larger than the largest magnitude recorded in historical times.

Major historical tsunamis in the eastern

Then we simulate the ensuing tsunamis using the Mirone version 2.70 (updated by 22

October 2016; Luis ( 2007)), highlighting the basic features of the wave propagation and roughly identifying the coastal sectors that are expected to suffer the largest tsunami impacts. The following describes the two scenarios used in the eastern and western Hellenic arcs :

The eastern Hellenic arc scenario

In the first scenario, we consider a Mw 8.9 earthquake generated on the eastern segment of thrust fault running parallel to Eastern Crete on the 1303 AD west Rhodos segment (Figs. 67 and72). The fault rupture geometry at the eastern segment of Crete Island used in this scenario is shown in Table 5 and consists in a thrust fault that belongs to the Hellenic subduction zone. The initial tsunami conditions for this first case are plotted in Fig.

67

. The maximum positive and negative initial water elevations are > 15 m and -16 m at the tsunami source, respectively.

In the following analysis of computed wave propagation, snapshot images show the tsunami fields every 0, 33, 50, 66, 80 minutes after the tsunami initiation (Figs. 68,69,70,71 and 72). The scenario describing the tsunami propagation after 50 minutes indicates that the wave arrives at the Kefr Saber and El Alamein investigated sites on the Egyptian coast with a wave height between 7-10 m (Fig. 70). The modelling results show that the entire Egyptian coast is affected by the tsunami triggered in the eastern Hellenic arc with a variation of the wave heights and arrival time. 4 and location in Fig. 67).

The western Hellenic arc scenario

In the second scenario, we consider a Mw 8.8 earthquake generated in the western segments of thrust fault running parallel to western Crete (Table 6 and Fig. 73). The initial tsunami condition for this second scenario is plotted in Fig. 74 and show the maximum positive and negative initial water elevations at the tsunami source are 11 m and -5.0 m, respectively.

The following snapshot images in Figs.74 to 78 show the tsunami wave propagation computed at different arrival times i.e. 0, 33, 66, 100, 150 minutes, after the tsunami initiation. Our observation is that the entire Egyptian coast is affected by the tsunami of the western Hellenic arc, but with a relatively long time of wave propagation with regards to the eastern Hellenic scenario.

The image snapshot of the tsunami propagation after 33 minutes shows that the wave arrives on the Libyan coast with a 4-10 m wave height (Fig. 75). The wave arrives at the Egyptian coast after 66 minutes (Fig. 76) with slightly lower wave height compared with the wave on the Libyan coast. The image describing the tsunami propagation after 100 minutes indicates that the waves arrive at the Egyptian coast with a 0.86-1.76 m wave height at Kefr Saber and a 0.44-0.87 m wave height the at El Alamein (Fig. 77). The tsunami waves from the western Hellenic arc source and scenario cover the entire Egyptian coast after 150 minutes (Fig. 78).

Table 6: Fault configuration (see Fig. 73) in the west Hellenic arc used for our modelling and scenario modified after Stiros, 2010.

Comparing my two scenarios with previous studies

Various numerical studies of tsunami modelling and estimation of the wave height run-up and wave propagation have been conducted for the eastern Hellenic arc (Hamouda, 2006 ;[START_REF] Mohammed | Impacts on Egyptian Coastal zones Eastern Mediterranean Tsunamigenic Earthquakes and their Geology[END_REF]Pagnoni et al. 2015), and for the western Hellenic arc (Hamouda 2009, Shaw et al., 2008, Pagnoni et al. 2015). Those studies have obtained different results with respect to the wave heights and the time of wave arrival on a given coastline. The differences arise because of a) the bathymetry data used the modelling has different resolutions, and b) various different fault rupture and surface deformation parameters have been used. The wave height run-up and wave propagation of these studies are summarized in Table 6.

Comparing my results with others studies helps to imagine all possible scenarios and how to deal with each in the case of a tsunami in the future (Table 7). My simulation results of the estimated wave heights at Salloum, Alexandria, Damietta well agree with Hassan, (2013) however, my results show higher estimated wave heights at Matrouh and El Arish for the Eastern Hellenic arc scenario (Table 7). Hamouda (2006Hamouda ( , 2009) ) Eastern Mediterranean from historical earthquake data.

CONCLUSION AND DISCUSSION

The two main seismic sources of the tsunami were the eastern and western Hellenic arcs in the Eastern Mediterranean. These sources are responsible for two large historical earthquakes and subsequent tsunamis, which affected Egypt on 21 July 365 and 8 August 1303 (Ambrayses, 2009). While the third seismic source is Cyprus zone and it was considered as a low potentiality of the tsunami.

I tested two programs of tsunami wave propagation in Eastern and western

Hellenic arc with scenarios using NAMIDANCE beta V.9.0, [START_REF] Velioglu | Performance Assessment of NAMI DANCE in Tsunami Evolution and Currents Using a Benchmark Problem[END_REF] and Mirone v. 2.7 (Luis, 2007). I succeeded to create an initial wave from Mirone v.2.7, 22

October 2016 updated. Two-tsunami scenario were developed with sources in the eastern and western Hellenic arcs. These tsunami events were based on the geological tsunami records in Kefr Saber and EL Alamein (see chapter IV for details about the historical events and tsunami deposits). The uncertainties of these two models depending on the chosen fault rupture data, the quality of the bathymetry data and the accuracy of the model used. The fault ruptures used in this study for the western Hellenic scenario are those calculated by [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF] and used in Pagnoni et al. (2015) study with changes in these fault parameters.

The uncertainties are calculated for the fault geometry (i.e length, width, and slip) used in east and west Hellenic arcs as it compared with the previous studies (see tables 5 and 6).

Also, the uncertainties are calculated in wave height (m) depend on the tested 5 scenarios resulted in ±5 m in wave height in case of east Hellenic arc scenario and ± 1.5 m in wave height in case of west Hellenic arc scenario.

We chose highest resolution bathymetry data available ( 30

CONCLUSIONS

The study of historical and instrumental seismicity, the focal mechanisms, stress inversions, GPS velocity vectors and the tectonic geology help me to characterize the seismotectonic of the Eastern Mediterranean and study the impact of past tsunami in the northern Egypt.

Firstly, the Eastern Mediterranean region is considered as a complex tectonics domain that can be studied in the frame of the collision between the Eurasian and African plates. In Eastern Mediterranean, the African plate subducts underneath Eurasia along the Hellenic Arc at a rate of about 0.5-1 cm/year, while the Aegean Sea represents an extensional basin with opening rates in the order of 3.5-4 cm/year [START_REF] Mcclusky | Global Positioning System constraints on plate kinematics and dynamics in the eastern[END_REF].

In the eastern Mediterranean region, the Cyprian Arc is the expression of the convergence between the Africa plate and the Anatolia microplate and characterized by the formation of Eratosthenes Seamount. It has been deformed in late Cenozoic [START_REF] Ben-Avraham | Plate convergence in the Cyprian Arc[END_REF][START_REF] Kempler | Structures and kinematics in the northeastern Mediterranean: a study of an irregular plate boundary[END_REF] the northwest-southeast Temsah zone; the northeast-southwest Rosetta zone, and the eastwest to ENE-WSW continental fault trends (Abdel [START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF].

The largest historical seismic events of the Egyptian continental margin are the 320 and 956 AD earthquakes, while the largest instrumental earthquake occurred on September 12, 1955 with Ms 6.7 (Costantinescu et al., 1966) in the continental shelf of the Nile Delta.

The historical AD 320 and 956 seismic events occurred north of the epicenter of September 12, 1955 (Ms =6.8) earthquake (Korrat et al., 2005). These earthquakes were followed by other large events that occurred within 57 years on the October 19, 2012 event at 03:35:11. max orientation and a secondary E-W to NW-SE orientation. Our stress results do not agree with break hole data of [START_REF] Tingay | Present-day stress-field rotations associated with evaporites in the offshore Nile Delta[END_REF] in case of Rosetta trend this due to that the borehole data have a shallow depth rather than the depth of the earthquakes.

The second active zone in northern Egypt is Dahshour zone (B). This zone is located in the northern part of the Western Desert and in the west of the Cairo Suez zone. The largest event in the Dahshour zone with M L 5.9 is the 12 October 1992 event which has great damage mainly in Cairo (see chapter III for detail information). 15 collected focal mechanisms in this zone show normal faulting with nodal planes trending NW-SE to E-W with strike-slip component [START_REF] Maamoun | Detailed Studies of 12 October, 1992 Earthquake[END_REF]Hussein, 1999). The stress inversion From the study of seismotectonic and paleotsunami events of seismic origin in the Eastern and northern Egypt, four active zones are identified to be the source of possible tsunamis. The eastern Hellenic arc, Western Hellenic arc, Cyprian arc, Egyptian continental margin. The Eastern and Western Hellenic arcs are considered as the highest active far-field tectonic zones and a major source of tsunamis that may strike the Egyptian coasts and adjacent Mediterranean regions. The historical seismicity catalogue reports three significant earthquake events of the Hellenic subduction zone with major tsunamis that have affected the Mediterranean coast of Egypt:

1) The earthquake and tsunamigenic event of 21 July 365 (Mw 8. 3 8.5;Stiros and Drakos, 2006;Shaw et al., 2008),

2) The earthquake and tsunamigenic event of 8 August 1303 (Mw 7.8 8.0) (Abu El Fida, 1329) 3) The earthquake and tsunamigenic event of 24 June 1870 (M L 7 -7.5) [START_REF] Ben Menahem | Earthquake catalogue for the Middle East (92 B.C. to[END_REF].The three events have generated great damage in the coast of Egypt and affected especially the Alexandria city with coastal flooding and inundations (The reported as the water in the new port of Alexandria splashed out onto the quay (Ambraseys 1961).

The others two zones of the less active tsunamis sources are the Cyprus arc and the Egyptian continental margin. The highest magnitude reported in earthquake catalogues for Cyprus is7.5 and refers to the 11 May 1222, AD earthquake. This Earthquake was followed by low tsunami impacts along the Egyptian-Mediterranean coastal zone Ambraseys (1995).

The largest earthquakes have occurred in the Egyptian continental margin as example offshore Alexandria earthquake Ms 6.7 on September 12, 1955 (Hussein et al., 2005). It is located in the sedimentary cone of the Nile that poses the potential for landslides tsunamis [START_REF] Garziglia | Mass transport deposits on the Rosetta province (northwest Nile deep-sea turbidite system, Egyptian mar-gin): characteristics, distribution and potential causal processes[END_REF]. Five trenches were carried out in Kefr Saber ~32-km west of Marsa-Matruh city. 12 cores were carried out in the second selected site of El Alamein. The cores were carried out using cobra drilling instrument. The size of the trenches were~2 x 1 meter with ~1.5-mdepth and the maximum depth of cores is ~2.6 m.

Trenches are logged and photographed with detailed description and sampling during the field works in Kefr Saber. While the cores carried out in ElAlamein site were split in two half in the NRIAG Laboratory with Fisher Wire. One for archive and the other for the analysis of sedimentation and content. The studied core includes the collection of samples for dating, photography, detail stratigraphic descriptions, X-ray scanning, geochemical analysis and magnetic susceptibility. The main target is to identify the Paleotsunami deposits in the stratigraphic logs according to tsunami signatures. The stratigraphic logs in cores show four main tsunami layers; A) The first layer is ~7.5-cm-thick at ~19cm-depth and is made of poorly sorted white sandy deposits with high broken gastropods and lamellibranch fossils. The high value of organic matter and the high peak of magnetic susceptibility reflect a rich content in carbonates and quartz. B) The second layer is ~13-cm-thick at ~50-cm-depth characterized by white sandy deposits intercalated with coarse brown sand with horizontal lamination, poor sorting sediments, rich in total organic matter and a high peak of magnetic susceptibility. C) The third layer ~ 18 cm-thick at 89-cm-depth is made of yellow sand mixed with white sand intercalations, with laminations at the bottom of deposits, vertically and horizontal gastropods directions reflect high wave current, broken shells fragments, rich in total organic matter and pyrite showing a high peak of magnetic susceptibility. D) The fourth tsunami layer is at 151 cm depth with thickness 19 cm. It is characterized by pale yellow sand, medium to fine, with broken shells fragments and extremely poor sorting, with a high peak of magnetic susceptibility, and a high peak of organic matter > 5.5 weight percentage and high amount of gypsum.

Two worst simple scenarios with high possibility active tsunami sources were built up by creating the initial wave of calculated fault ruptures for the Western Hellenic and Eastern Hellenic arcs. This modelling depends on the presence of geological record of 21

July 365 and 8 August 1303 in the northern Egyptian coast in Kefr Saber and El Alamein.

The location of Eastern and Western Hellenic arc scenarios depends on historical tsunami information for 21 July 365 [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF]) and 8 August 1303 (Abu Fida, 1329;Guidoboni and Comastri, 2005). The chosen fault parameters depended on the calculated western Hellenic arc [START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF] and of eastern Hellenic arc (Pagnoni et al., 2015) with scenario tests to the focal mechanisms of large earthquakes in the recent time. The magnitudes of earthquakes were estimated to be equal or larger than the highest magnitude recorded in historical times (Table 4). Then we simulate numerically the ensuing tsunamis using the Mirone software (Luis, 2007). The used bathymetry data is the 30 arc seconds grid from the available GEBCO data online, and this in the absence of the more detail resolution

(1 or fewer arc seconds) of coastal bathymetry data in my study area.

In the Eastern Hellenic scenario, the computed wave propagation is performed every 0, 33, 50, 66, 80 minutes. After 30 minutes, the initial wave arrives and after 50 minutes where the maximum wave heightreaches7-10 meters in Kefr Saber and El Alamein sites. In the Western Hellenic scenario, the tsunami wave propagation is computed at 0, 33, 66, 100, My results are compared with previous studies of (Hamouda, 2006) for the Egyptian coast; [START_REF] Mohammed | Impacts on Egyptian Coastal zones Eastern Mediterranean Tsunamigenic Earthquakes and their Geology[END_REF]Pagnoni et al., 2015) in case of Eastern Hellenic arc scenario, and for the western Hellenic arc (Hamouda, 2009;Shaw et al., 2008, andPagnoni et al., 2015). My results are in agreement with modelling of (Hassan, 2013) for the wave height at Salloum, Alexandria, Damietta in case of Eastern scenario and appear to be different from the result of (Hamouda, 2005;andPagnoni et al., 2015). My results agree well with the size of tsunami wave inferred from the model of Shaw et al., (2008) wave height to Alexandria in case of the Western Hellenic scenario.

Some perspectives are suggested in this thesis for the seismotectonic and paleotsunami studies as follows: and are classified according to local, regional, basin-wide. For instance, according to [START_REF] Salamon | Potential tsunamigenic sources in the eastern Mediterranean and a decision matrix for a tsunami early warning system in Israel[END_REF] the messages may be related to local ( -400 km) or basin-distances. In case of the Egyptian coastal zones, we consider the east Hellenic arc (EHA) and Western Hellenic arc (WHA) are the regional message of 100-400 km.

2) The whole subduction Hellenic zone represents a serious tsunami hazard for the eastern Mediterranean and as evidence from tsunami deposits analyzed in this study. The probable activation of the Hellenic arc or even the Cyprian arc with a major earthquakes Mw >8 will generate a strong tsunami on the Egyptian coast. Therefore, the first step for civil protection is in the preparation of the early warning system and evacuation plan for a probable near future tsunami effects on the Egyptian coasts. ----------------- (1997) 86.2 76.13 -148.33 347.78 59.35 -16.18 311 32 214 11 AbouElenean (1997) 73.99 80.04 -150.11 338.32 60.60 -11.45 300 28 203 13 AbouElenean (1997) 75.45 47.25 -150.94 324.79 69.10 -46.6 280 47 25 13 AbouElenean (1997) 92.63 73.21 -143.41 350.53 55.20 -20.59 84 77.43 -148.5 196.24 59.34 -14.66 303.34 80.49 -119.89 197.32 31.23 -18.57 The Focal mechanisms are represented as a beach ball [START_REF] Sykes | Mechanism of earthquakes and nature of faulting on the mid ocean ridges[END_REF]) in which the lower hemisphere stereographic projections show two black quadrants and two white quadrants separated by great circles arcs oriented 90 from each other. The great circle arcs are the nodal planes, one of which coincides with the fault rupture that generates the earthquake. The strike of the fault is indicated by a line connecting the two points at which the great circle corresponding to the fault intersects the outer edge of the beach ball diagram (fig. 2). The dip direction is 90 from strike, in the direction indicated by the bold arrow from the center of the plot to the middle of the great circle arc.

Appendix A : Focal mechanism and historical earthquakes

The rake of the hanging wall slip vector [START_REF] Cronin | Preliminary assessment of the seismicity of the Malibu Coast Fault Zone, southern California, and related of philosophy and practice[END_REF] is measured in the fault plane, relative to reference strike of the fault plane. An angle measured through an anticlockwise rotation from the reference strike is considered a positive angle; an angle measured clockwise from reference strike is a negative angle.

A slip vector that is directed up relative to strike has a positive rake and a slip vector that is directed down the plane is negative. The range of permissible rake is +180 to -180 . According to [START_REF] Seismotectonic Methodology Aki | Analysis of seismological data[END_REF], a rake of 90 indicates slip that is entirely reverse with no strike slip component. Similarity, hanging wall slip vectors with negative rake have at least some component of normal slip with rake of -90 indicating slip that is entirely normal with no strike slip component.

Stress tensor rizontal

directions. [START_REF] Anderson | The dynamics of faulting and dyke formation with applications to Britain[END_REF] developed a simple scheme connecting the basic stress -existing fault in the crust (Fig. 3). [START_REF] Anderson | The dynamics of faulting and dyke formation with applications to Britain[END_REF] crust [START_REF] Wallace | Geometry of shearing stress and relation to faulting[END_REF]Bott,1959;[START_REF] Mckenzie | The relation between fault plane solutions for earthquakes and the directions of principal stresses[END_REF]. This seismological data is considered as an excellent source ofinformation on stress directions and relative stress magnitudes in the crust which alsogives an clear picture of the present-day stress field.

on the left and corresponding faulting regimes in the right.

Stress tensor is describe as the concentration of the internal forces considering not only their magnitude but also the size of the area on which they act (i.e., a force divided by an area that is a stress (F/A)) [START_REF] Ramsay | The techniques of modern structural geology[END_REF][START_REF] Parry | Mohr circles, stress paths and geotectonics[END_REF].

It is related to the familiar concept of a force in a reasonably straight forward way.

Hence the forces acting on elements of an elastic solid can be treated with the concept of stress vector and stress tensor. The stress tensor ( ij), the full specification of the state of stress at a point, is made up of six independent components corresponding to three traction vectors each acts on a surface perpendicular to x, y, and z coordinate axes. These terms represent the complete internal force distribution at a point.

The diagonal terms of stress tensor are called normal stresses (three components) and the off-diagonal terms are called shear stresses (six components).

Components of stresses on a Fault plane

It is considerable interest to know the direction of the shear stress acts as generally assumed that the shear stress derives the potential slip on the fault plane. To this, one consider a fault plane L which can defined by a unit vector n = (n1, n2,n3 normal to it, and a, the stress vector acting on that plane and represent the state of stress on the rock volume. Performing all calculations in the principal stress system, we can easily obtain the total traction acting on the fault surface as: To obtain the normal stress acting on the considered plane, we project the stresses of equations ( 3) onto the normal n to get:

The shear traction ) is found by subtracting the normal traction from the total traction:

lane with unit normal n result of tectonic forces as it causes earthquake faulting and seismic wave propagation effects like anisotropy. To find best the deviatoric stress tensor, only orientation of the slip with respect to the orientation of the fault is consider [START_REF] Michael | Determination of stress from slip data: Faults and folds[END_REF].

The Right Dihedron and rotational optimization method

The Right Dihedron method was introduced by Angelier & Mechler (1977) as a 3 stress axes in fault analysis. These methods developments include (1) the estimation of the stress ratio R, ( 2) the complementary use of tension and compression fractures and (3) the application of the a compatibility test for data selection and subset determination using a counting deviation. The Right Dihedron method is typically designed for building initial data subsets from the raw data set, and for making a first estimation of the four parameters of the reduced stress tensor. The Improved Right Dihedron method forms a separate module in the TENSOR program [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF].

The Right Dihedron method is based on a reference grid of orientations predetermined in as a rectangular grid on the stereonet in lower hemisphere Schmidt projection. For all fault-slip data, compressional and extensional quadrants are The stress ratio R, defined as equivalent -four parameters determined in the stress inversion, with the three principal stress axes

The stress ratio, R controls for any given plane, the direction of shear stress and determines the geometry of the slip on fault planes [START_REF] Wallace | Geometry of shearing stress and relation to faulting[END_REF]Bott, 1959).

Also, the stress ratio R can be obtained with this relation:

R= (100-sval)/100

where S2val is the counting value of the point on the reference grid nearest to the orientation of This formula is only good valid for large fault populations with a wide variety of fault plane orientations.

The Improved Right Dihedron method allows us a first estimation of the orientations of the principal stress axes and of the stress ratio R, and a first filtering of compatible fault-slip data. The selected fault-slip population and the preliminary tensor can be used as a starting point in the iterative inversion procedures like the Rotational Optimization method in the following lines:-

The used Right Dihedron method in combination with the four dimensional iterative Rotational Optimization method for determining the four parameters of the reduced stress tensor using the TENSOR program of [START_REF] Delvaux | Neotectonics of the Mbeya area, SW Tanzania[END_REF]. The improved version of Right Dihedron method by Delvaux and Spemer (2003) allows not only obtaining the first estimation of the principal stress axes orientation but also estimating the stress ratio R and produces the first filtered focal mechanism data set by application of a compatibility test for data selection and subset determination on the basis of the counting deviation. These results are used as a starting point in the Rotational Optimization inversion procedure. This new iterative inversion method is based on a controlled grid search with rotational optimization of a range of misfit functions with the purpose of minimizing the misfit function. It allows restrictions of the research area during the inversion so that there is no need for the whole grid to be searched. The misfit is defined as the minimum rotation that is necessary to reconcile the stress tensor with the Observed slip vector direction to all fault plane solutions for a population of earthquakes.

The stress tensor orientation that provides the average minimum misfit is assumed to be the best one for a given populations of focal mechanisms. The TENSOR program [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF] deviation (e.g., Vasseur et al., 1983;Gephart and Forsyth, 1984;[START_REF] Bergerat | Stress fields in the European platform at the time of Africa-Eurasian collision[END_REF] re than the threshold value of 30°), the value of composite function (the fault plane will be the one with the smallest value of the composite function the two planes have slip deviation less than 30° ) and internal friction criteria (the instability) for each fault plane [START_REF] Delvaux | Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program[END_REF].

3. Skewness is a measures the degree to which a cumulative curve approaches symmetry. Two samples may have the same average grain size and sorting but may be quite different to their degrees of symmetry. if the sample curve is better sorted in the tails than in the central portion, the curve is flat peaked or platykurtic. For normal curves = 1.00, leptokurtic curves have >1.00, and platykurtic curves have <1.00.

X-ray diffraction theory

Single wavelength incidents to the specimen surface and detector measure the intensity of the diffracted beam. The beam incident angle changes continuously thus a spectrum of diffraction intensity versus the angle between incident and diffraction beam is produced. This spectrum is compared with database containing over 60,000 diffraction spectra of known crystalline substances. Diffractometer functions are the x-ray diffraction detecting from material and the measuring of diffraction intensity.

Fig. 4 illustrated the geometrical arrangement of X-ray source, specimen and detector.

The X-ray radiation generated by an X-ray tube passes through special slits, which collimate the X-ray beam. These slits are commonly used in the diffractometer.

They are made from a set of closely spaced thin metal plates parallel to plane to prevent beam divergence in the director perpendicular to the figure plane.

Fig. 4 The geometrical arrangement of an X-ray source, specimen, and detector.

A divergent X-ray beam passing through the slits strikes the specimen. X-rays are diffracted by the specimen and form a convergent beam at receiving slits before they enter a detector. The diffracted X-ray beam needs to pass through a monochromatic filter (or a monochromator) before being received by a detector.

Relative movements among the X-ray tube, specimen and the detector ensure the recording of diffraction intensity in a range of 2 . The angle is not the angle between the incident beam and specimen surface; rather it is the angle between the incident beam and the crystallographic plane that generates diffraction.

Diffractometers can have various types of geometric arrangements to enable collection of X-ray data.

The technique of thin film X-ray diffractometry uses a special optical arrangement for detecting the crystal structure of thin films and coatings on a substrate. The incident beam is directed to the specimen at a small glancing angle rotates to obtain the diffraction signals as illustrated in figure 16. Thin film X-ray diffractometry requires a parallel incident beam, not a divergent beam as in regular diffractometry. Also, a monochromator is placed in the optical path between the X-ray tube and the specimen, not between the specimen and the detector. The small glancing angle of the incident beam ensures that sufficient diffraction signals come from a thin film or a coating layer instead of the substrate. The tsunami wave amplitude increases by its arrival to the coast and this depend on the relief of the sea-floor. A decrease in the water depth leads to a decrease in the wave propagation velocity and, consequently, to compression of the wave packet in space and an increase of its amplitude. In the case of catastrophic tsunamis, the run-up height reaches 10 30 m, while the wave is capable of inland inundation (runin) of 3 5

km from the coastline. A scheme of the tsunami onshore run-up, explaining the main parameters of this process, is shown in Fig. 6. The maximum wave height can be achieved at the shoreline, at the inundation boundary or at any point in between them.

.The process of the simulation process of the tsunami waves applied in this study are shown in Fig. 7. an integration model that can be found by performing integration from the bottom of the water to the water surface in a vertical direction.

Introduction:

Egypt has a well-documented catalogue of earthquakes and tsunamis preserved in a variety of sources due to its long history of civilization. Original documents and archives are considered as the principle sources of macroseismic data for major historical earthquakes and tsunamis (Poirier and Taher, 1980;Maamoun et al., 1984); Ambraseys et al., 1994Ambraseys et al., , 2009;;[START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF]Guidoboni et al., , 2005;;Soloviev et al. 2000). The catalogue reports that coastal cities of northern Egypt have experienced tsunamis inducing runup waves and inundations with severe damage (Ambraseys, 2009). While past tsunamis are well documented historically, it appears that there is a lack of holistic investigations for tsunami deposits along the Mediterranean coastlines. The coastal geomorphology with low-level topography, dunes and lagoons along the Mediterranean coastline of northern Egypt constitutes an ideal natural environment for the geological record of past tsunamis.

The Eastern Mediterranean area experienced large earthquakes that can be generally described in the frame of the convergence between the Eurasian and African plates [START_REF] Taymaz | Active faulting and crustal deformation in the Eastern Mediterranean region[END_REF]. Major historical tsunamis in the eastern Mediterranean region that affected northern Egypt are triggered by large earthquakes (Papadopoulos et al., 2014) [START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF], [START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF] and Ambraseys (2009).

Focal mechanisms are CMT-Harvard.

Tsunami research of the past 20 years has led to the discovery of tsunami deposits dating back to thousands of years. For instance, more than 6 soil levels were identified buried below catastrophic sand sheet deposits at Puget Sound coastline (west Washington, USA) due to tsunamis in the past 7000 years [START_REF] Atwater | Evidence for great holocene earthquakes along the outer coast of Washington state[END_REF]. Nanayama et al. (2003) In this paper, we investigate the paleotsunami deposits in northern coast of Egypt and their correlation with the historical tsunami catalogue of the Eastern Mediterranean. Using coastal geomorphology with trenching and coring, we examine the geological evidence of tsunami deposits using geochemical analysis, magnetic susceptibility and radiocarbon dating to identify the tsunamis records. The obtained results and inferred size of past tsunamis are compared to model wave heights propagation associated with major earthquakes. Finally, we discuss the impact of past tsunamis their dating and correlation with major tsunamigenic earthquakes of the Hellenic and Cyprus subduction zone.

Major historical tsunamis of the Mediterranean coast of Egypt

Although the tsunamis catalogue of Egypt is not completed yet, [START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF]Guidoboni et al. ( , 2005) ) and Ambraseys ( 2009) report several large historical earthquakes with tsunamis that caused damage in coastal Egypt and the eastern Mediterranean region (Table 1). Among these events, the tsunamis of 21 July 365, 8 August 1303 and 24 June 1870 caused severe damage to Alexandria city as well as the Mediterranean coast of Greece, Sicily, Libya, Cyprus, Syria, Lebanon and Palestine. These three tsunami events are correlated with the major earthquakes in the Hellenic and Cyprus subduction zones (Papadopoulos et al., 2014). Early in the morning of 21 July 365, an earthquake with estimated magnitude ~Mw 8-8.5 located offshore West of Crete generated a major tsunami that affected the eastern Mediterranean coastal regions (Ambraseys et al., 1994;[START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF][START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF]Shaw et al., 2008). A contemporaneous account from the Roman historian Ammianus Marcellinus (born 325 400; [START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF] reports the sudden retreat of the sea and t with inundation and damage to the Alexandria harbour and city with ships lifted inland on house roofs; the estimated wave height of this tsunami was calculated by Hamouda (2009) to be larger than 8 m in Alexandria.

Date

On 8 August 1303 a major earthquake with magnitude ~Mw 8 located in between Crete and Rhodos islands generated a tsunami that greatly damaged the coastal cities of the eastern Mediterranean (Guidoboni and Comastri, 2005;Ambraseys, 2009). The contemporaneous Arabic source of Abu-El Fida (1329) report that the Alexandria city and Nile delta were flooded and many houses were damaged in Cairo and northern Egypt. In Alexandria, part of the city walls collapsed, the famous light houses was destroyed and some ships were torn apart carried up inland due to the tsunami waves (Abu-El Fida, 1329). .

On 24 June 1870 a large earthquake affected many places of the eastern Mediterranean region and was felt in Alexandria at around 18 h with no damage in the city but with slight damage in Cairo (Coumbary, 1870;Ambraseys, 2009). In Alexandria coastline and Nile Delta, the sea wave flooded the quays of ports and inland fields.

Among these three reported earthquakes, it appears that the AD 365 and AD 1303 can basin-wide impacts, while the 1870 earthquake may be of a lower magnitude (Mw ~7 7.5;Soloviev, 2000). However, all studies of the three historical earthquakes refer to tsunami waves with inundation in Alexandria and coastlines of northern Egypt and therefore with the potential of tsunamis record in sedimentary deposits.

Coastal geomorphology and site selection of paleotsunami records

The northwest Mediterranean coast of Egypt forms the northern extremity of the Miocene Marmarica homoclinal limestone plateau, which extends west of Alexandria for about 500 km acting as a major catchment area feeding the drainage system (Figure 1). The Coastal dune-ridges constitute an outstanding land feature at several locations parallel to the shoreline and protect inner lagoons from the sea. These dunes are completely weathered where the headlands exist [START_REF] Abbas | Ecological studies in coastal sand dune rangelands in the North-West of Egypt, Meeting of the Sub-network on Mediterranean Forage Resources of the FAO-CIHEAM Inter-regional Cooperative Research and Development Network on Pastures and Fodder Crops[END_REF]. The 2 to 30-m-high coastal beach-dune ridge mainly composed of oolitic and biogenic calcareous sand separates coastal lagoons and sabkhas (salt lake) from the sea, the beach dunes; the beach-dune ridge is developed along the receding Quaternary shorelines and embayment of the Mediterranean Sea [START_REF] Hassouba | Quaternary Sediments From the Coastal Plain of Northwestern Egypt (from Alexandria to Elomayid)[END_REF].

The lagoons with flat depressions separated from the sea by the coastal dunes (with different heights and sometimes with seawater oultlets) are designated sites that may record past tsunami deposits.

The selected sites were chosen taking into account geomorphological and topographic setting, the accumulation of boulders as witness of past tsunami events along the coast (Shah-

Selected sites and used methods for paleotsunami investigations

The trench sizes are ~2 x 1 meter with ~1.5-m-depth and all trench walls exposed finegrained sedimentary layers and were logged in details. The maximum core depth is ~2.6 m and their distribution in the lagoons was planned to occupy an area from the depression (depo-center) to the edge close to the outlet of seawater in order to observe any thickness variation of tsunami layers.

The core tubes were split in half lengthwise, photographed using both normal and ultra-violet lightning accompanied by detail description of textures and sedimentary structures. The X-ray scanning was performed immediately after core opening and cores were sent to the laboratory of the National Institute of Geophysics and Astronomy (NRIAG, Cairo)

for sampling and further analysis. The magnetic susceptibility measurements were operated along cores and samples were collected for radiocarbon dating, physical, chemical and organic matter analyses. The arrows show the high values of each measurement that may correlate with tsunami deposits.(Similar illustrations of cores 2 to 12 are in supplemental materials).

Description of trenches and cores sedimentary layers

The selected sites revealed a succession of sedimentary units typical of lagoon deposits with fine strata made of a mix of fine gravel, sand, silt and clay. At both Kefr Saber and El Alamein sites, trenches and cores present comparable soft sediment content and stratigraphy, but with some differences due to their distance from the shore, situation in lagoons and with regards to the dune heights.

Trenches at Kefr Saber: Trenches P1, P2, P3 and P4 have quite similar sedimentary succession with fine-grained mostly alluvial deposits made of sandy-silty layers with mixed coarse and white fine sand with broken shells of marine origin (Fig. 3 and trench logs in supplemental material S1). A layer with white mixed sand, gravel and broken shells with variable 2 to 15 cm thickness is found at 30 50 cm depth in P1, P2, P3 and P4. The white sandy layer is deeper (larger than 30 cm) in trench P3 and P4 located in the lagoon depocenter. Trench P5 which is close to the dunes and shoreline show a succession of coarse and fine sand and about 30 to 40 cm thick mixed with pebbles. The layer characterized by highenergy sedimentary deposits is interpreted as of tsunami origin.

Two charcoal samples collected in Trench P1 at 35 cm and 53 cm depth display modern age (younger than 1650 AD) and 39000-38250 BC, respectively. In Trench P2, two other charcoal samples collected at 73 cm and 100 cm depth and both below the tsunami layer 1 (Fig. S1-b) indicate 50 -70 AD and 5300-5070 BC, respectively (see also Table 2a). In Trench P4, four collected charcoal samples at 15 cm, 25 cm, 40 cm and 61 cm depth reveal modern ages (younger than 1650 AD). A fifth charcoal sample located at 60 cm depth provides 17200-15900 BC. In Trench P5, four charcoal samples are collected with the uppermost located at 12 cm depth is dated at 360 -50 BC, the second sample at 17 cm depth show 30-180 AD, the third, and fourth charcoal samples found at 33 cm and 37 cm depth are dated at 350 -1050 BC and 2400 -4000 BC, respectively.

Although the sedimentary deposits in trenches at Kefr Saber and related modern, young and old dates may indicate reworking, the well identified mixed coarse and fine white sand with broken shells of marine origin at ~ 30 -73 cm depth may well be correlated with

I

  would like to thank Profs.Ana Maria Viana Baptista, Christophe Morhange, Ahmet Yalciner, Hesham Hussein and Assoc.Prof. Mohamed El Gabry for their acceptance to be among the jury members. I would like to express my appreciation to Profs. Hatem Odah, Hesham Hussein for their scientific and logistic support during the field works and my work progress.I am grateful to Drs. Said Maouche, Assia Harbi, Saud Abdelhady, my NRIAG colleagues Sayed Mekhaimr, Hany Hassen, Adel Sami, Mohamed Maklad, Mohamed Sayedandmy friend Grant Wilson from New Zealand for their keen efforts and help during the development of this work. I wish also to thank the Institut Français du Caire and the French-Egyptian IMHOTEP program for their interest and support. I would like to express my appreciation to central metallurgical research centre laboratory, for the geochemical analysis. Also, Thanks to the International Hydrographic Organization (IHO) and the Intergovernmental Oceanographic Commission (IOC) of UNESCO for providing me Bathymetry data 2014 of the Eastern Mediterranean which was helpful in the tsunami modelling. The scientific results of stress inversion in chapter III were obtained using Win-Tensor, a software developed by Dr Damien Delvaux, Royal Museum for Central Africa, Tervuren, Belgium. I am also grateful to the French Centre d'études Alexandrines for providing their drilling equipment. Special thanks to Egyptian Armed Forces for issuing permissions and their support during field work. I am also thankful to my PhD students colleagues Souhila Bagdi-Issaad and Jugurtha Kariche for their support during my stay at the IPG Strasbourg. This PhD thesis is conducted in the frame of the scientific cooperation between the National Institute of Geophysics and Astronomy (NRIAG, Cairo), and Ecole et Observatoire des Sciences de la Terre (EOST -IPGS) Université de Strasbourg, France, and the IMHOTEP bilateral French-Egyptian cooperation program (Campus-France) and European project ASTARTE. The NRIAG scientific foundation and the ASTARTE EC-funded project iii support my research work in the field and at the laboratory. In addition, the IMHOTEP project (CMEP, Campus France) funded my stay at EOST during my study.

Fig. 8 :

 8 Fig. 8: Morphotectonic map of the Mediterranean with major, simplified geological structures offshore constructed based on bathymetry data of ETOPO1 (1 min arc-minute global relief model of Earth's surface; https://www.ngdc.noaa.gov/mgg/global/, Reilinger et al. 2006).

Fig. 9 :

 9 Fig. 9: Map of the Egyptian continental margin with major simplified geological structures onshore and offshore based on tectonic tectonics structures elements from (Abdel Aal et al. 1994); Egyptian geological map EMRA, 2008; bathymetry data of ETOPO1 (1 min arc-minute global relief model of Earth's surface; https://www.ngdc.noaa.gov/mgg/global/).

Fig. 10 :

 10 Fig. 10: Tectonic geological map of Sinai constructed based on Egyptian geology map EMRA, 2008 using ArcGIS map version 10.2 Software.

Fig. 11 :

 11 Fig. 11 : Tectonic geology map of the north western Desert constructed based on Egyptian geological survey EMRA, 2008 using ArcGIS map version 10.2 Software.

Fig. 15 :

 15 Fig. 15: Historical earthquakes in Eastern Mediterranean and North Egypt (see historical earthquakes references Table13of the historical earthquakes in Appendix A

Fig. 19 :

 19 Fig. 19: Focal mechanisms of 19 earthquakes M L the Dahshour area (see reference Tables2 and 4in Appendix A).

Fig. 20 :

 20 Fig. 20: Focal mechanisms of 12 earthquakes with M L -Suez area (see reference Tables5 and 6in Appendix A).

Fig. 21 :

 21 Fig. 21: Focal mechanisms of 15 earthquakes with M L magnitude in the northern of Gulf of Suez (see reference Tables 9 and 10 in Appendix A for the focal mechanism solutions).

Fig. 22 :

 22 Fig. 22: Focal mechanisms of 29 earthquakes M L magnitude in south Gulf of Suez (see reference Tables 11 and 12 in Appendix A for focal mechanism solution).

Fig. 24 :

 24 Fig. 24: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at continental margin Zone A, Trend A.

Fig. 25 :

 25 Fig. 25: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at continental margin Zone A, Trend B.

Fig. 26 :

 26 Fig. 26: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at Dahshour Zone Zone B.

Fig. 27 :

 27 Fig. 27: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at Cairo-Suez zone, Zone C.

Fig. 28 :

 28 Fig. 28: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at Northern Gulf of Suez, Zone D.

Fig. 29 :

 29 Fig. 29: Parameters of the present day stress tensor deduced from focal mechanisms data at Southern Gulf of Suez, Zone E .

Fig. 30 :

 30 Fig. 30: Parameters of the present day stress tensor deduced from focal mechanisms data at Gulf of Aqaba, subzone F.

Fig. 31 :

 31 Fig. 31: Parameters of the present day stress tensor deduced from focal mechanisms data at Gulf of Aqaba, subzone G.

Fig. 33 :

 33 Fig. 33: The location map of the studied areas in northern Egypt.

Fig. 35 :

 35 Fig. 35: Sand dunes along Mediterranean coast west Mersa Matrouh.

Fig. 37 :

 37 Fig. 37: Large boulders in Ras EL Hekma

Fig. 39 :

 39 Fig. 39: Pumping machine to discharge the underground water

Fig. 41 :

 41 Fig. 41: The end of core tube.

Fig. 42 :

 42 Fig. 42: The preparation of core.

Fig. 43 :

 43 Fig. 43 : Sampling sketch of the split cores : a) the archive core part ; b) the working core part ; and c) the measurement analysis each 2 cm slices divided into 3 small part.

Fig. 44 :

 44 Fig. 44 : a) Coastal zone at Kefr Saber rich in boulders, b) Dendropoma fossils rich in the boulders, and c) the location of the five trenches P1 to P5 at Kefr Saber.

Fig. 45 :

 45 Fig. 45: Description of trench no.1. The arrow reflects tsunami layer 1 which is rich in broken shell fragments.

Fig. 46 :

 46 Fig. 46: Description of trench no.2. The arrow reflects tsunami layer 1 which is rich in broken shell fragments.

Fig. 47 :

 47 Fig. 47: Description of trench no.3. The arrow reflects tsunami layer 1 which is rich in broken shells fragments.

Fig. 49 :

 49 Fig. 49 : Description of trench no.5.

Fig. 66 :

 66 Fig. 66: Composite section for the cores in El Alamein.

Fig. 67 :

 67 Fig. 67: Bathymetry data from Gebco (2014) (30 arc seconds) with the location of the fault rupture zone (box) along the Hellenic subduction between Crete and Rhodos as the seismic source for the first scenario.

Fig. 68 :

 68 Fig. 68: Initial wave of the eastern Hellenic arc scenario

Fig. 71 :

 71 Fig. 71 : The wave height after 66 minutes of wave propagation in the eastern Hellenic arc scenario. Wave heights of 7 m reach northern Egypt.

Fig. 72 :

 72 Fig. 72: The wave height after 80 minutes of wave propagation in the eastern Hellenic arc scenario. Wave heights of 4 m reach northern Egypt.

Fig. 73 :

 73 Fig. 73: Bathymetry data from Gebco (2014) (30 arc seconds) with the location of the fault rupture zone (box) along the Hellenic subduction west of Crete as the seismic source for the second scenario.

Fig. 74 :

 74 Fig. 74: Initial wave of the Western Hellenic arc scenario.

Fig. 75 :

 75 Fig. 75: The wave height after 33 minutes of wave propagation in the Western Hellenic arc scenario.

Fig. 78 :

 78 Fig. 78: The wave height after 150 of wave propagation in the Western Hellenic arc scenario.

Fig. 79

 79 Fig.79 a. wave height (m) with the time at Kefr Saber in West Hellenic scenario

  The chapter III presents seismotectonic of the northern part of Egypt and show the tectonic and geologic framework of the active zones in northern Egypt and the Eastern Mediterranean. The historical and instrumental seismicity was collected from 2200BC to 2016 in the Eastern Mediterranean and northern Egypt. Six seismic tectonic sources are recognized in northern of Egypt: the Egyptian continental margin (Trend A and Trend B), Dahashour zone, Cairo-Suez zone, Northern Gulf of Suez, Southern Gulf of Suez, Gulf of Aqaba (subzones f and g). We also collected all focal mechanisms of earthquakes that occurred in active tectonics zones in and around the northern Egypt from 1951 to 2016.

  Libye. Une recherche sur la sismicité historique et instrumentale associée à des travaux sur les failles actives et mécanismes au foyer des principaux séismes avec une étude sur le tenseur de contrainte est utilisée afin de déterminer les caractéristiques de la receler des traces de tsunamis par le biais de tranchées et sondages carottées, notamment sur corrélation des dépôts catastrophiques datés avec le catalogue de sismicité historique de ux tsunamis ayant affecté les régions côtières. 3) Une modélisation des tsunamis liés aux séismes majeurs de la ique.

  Méditerranée, parmi les études sur les paléo-tsunamis, De Martini et al. (2012) ont identifié deux dépôts de tsunamis au cours du premier millénaire avant J.-C. et un autre en 650-770 après J.-C. et ont estimé un intervalle de récurrence moyen pour les tsunamis forts d'env. 385 ans (en utilisant la chronologie comprennent C14, Pb 210 et Cs 13, OSL et téphrochronologie) le long de la côte orientale de la Sicile, en Italie. Le long de la côte algérienne, Maouche et al. (2009) ont identifié la présence de gros blocs de Tipaza à Dellys comme étant liée à des événements de tsunamis en 419 et 1700 en utilisant la datation au radiocarbone des bioindicateurs. Les principales idées et fondements méthodologiques de mon travail y sont inclus e de tsunami sur le nord de tsunami et de hauteurs de vague sont également présentés. Ce chapitre continue de décrire les bases de la modélisation des tsunamis pour estimer la hauteur des vagues et le temps de trajet jusqu'à la côte nord de l'Égypte et les effets de champ lointain provenant des sources sismiques des arcs helléniques de l'Est et de l'Ouest. À la fin du chapitre I; il résume brièvement les idées principales des chapitres de thèse. Le chapitre II montre les méthodes utilisées lors des travaux de cette thèse que je active basée notamment sur les failles actives et les mécanismes au foyer des séismes majeurs associés. Ces travaux la méthode « Right Dihedron 1993). Cette méthode consiste à séparer les données brutes du mécanisme focal collecté de 1951 à 2016 en sous-ensembles tout en optimisant le tenseur des contraintes à l'aide de la méthode « Right Dihedron » et de l'Optimisation rotationnelle pour chaque zone active. La méthode d'optimisation rotationnelle a été utilisée pour la détermination des quatre paramètres de contrainte, 1, 2, 3 et le rapport de contrainte R = ( 2 -3) / ( l -3);

  l'Egypte et montre le cadre tectonique et géologique des zones actives du nord de l'Egypte et de la Méditerranée orientale. La sismicité historique et instrumentale a été collectée entre 2200 avant le siècle a' 2016 en Méditerranée orientale et au nord de l'Egypte. Six sources tectoniques sismiques sont reconnues dans le nord de l'Égypte: la marge continentale égyptienne (Tendance A et Tendance B), la zone Dahashour, la zone Le Caire-Suez, le nord du golfe de Suez, le sud du golfe de Suez et le golfe d'Aqaba. . Nous avons également collecté tous les mécanismes focaux des séismes survenus dans ces zones de tectonique active de 1951 à 2016. Les solutions du mécanisme foca journaux égyptiens. territoire. J'ai compilé les solutions du mécanisme focal et calculé les inversions de contraintes du catalogue sismique de l'Egypte, recherché et cartographié les failles actives, et utilisé les données de forage pour développer une analyse sismotectonique de la distribution des contraintes dans ma région d'étude. Les données sismologiques et les mécanismes focaux associés sont considérés comme une excellente source d'informations sur la direction du stress dans la croûte, qui fournit des informations précises sur le champ de stress actuel dans la région de la Méditerranée orientale et le nord de l'Egypte. Plusieurs études portent sur les inversions sismotectoniques et de stress en Afrique du Nord et en Méditerranée orientale

  tsunami pour la Méditerranée orientale et comme preuve des dépôts de tsunami analysés dans cette étude. L'activation probable de l'arc hellénique ou même de l'arc cyprien avec un séisme majeur Mw> 8 va générer un fort tsunami sur la côte égyptienne. Par conséquent, la première étape pour la protection civile est la préparation du système d'alerte précoce et le plan d'évacuation pour un probable probable tsunami sur les côtes égyptiennes. Mes perspectives sont suggérées pour les études sismotectoniques et paléontunami comme suit: Premièrement, il n'a pas été possible d'effectuer des études de terrain détaillées sur les zones sismiques actives et les failles actives du Quaternaire. Cependant, des failles dans la zone du Caire-Suez et des failles d'EL Alamein ont été réalisées lors des premières investigations en octobre 2015 et des reconnaissances ont été effectuées. Il n'y a jamais de problème pour effectuer des mesures de champs détaillées pour la faille quaternaire active d'El Alamein pour la perspective future. Deuxièmement pour l'étude paléontunami, a) Des investigations sur le terrain sont prévues sur le site de la ville de Thonis Heracleion, ancienne cité historique égyptienne située dans l'embouchure canopique du Nil, à 32 km au nord-est de la côte d'Alexandrie. Cette ville aurait été inondée apparemment à la suite d'un tsunami majeur xxxvi b) Compléter le carottage et les investigations précédentes dans d'autres sites situés de Kefr Sabr à Salloum pour déterminer une éventuelle inondation du tsunami historique à l'intérieur des terres le long de la côte nord de l'Egypte. c) Créer un scénario potentiellement pire pour l'heure d'arrivée et la hauteur des vagues du tsunami pour les projets stratégiques construits sur la côte égyptienne tels que la ville de New El Alamein et la centrale nucléaire égyptienne.

Fig. 1 :

 1 Fig. 1 : Seismic activity and tectonic map based on (a geological map of Libya, 1985; geological map of Egypt EMRA, 2008;Bathworth, 2008) and seismicity data for north Egypt of NRIAG bulletin from 1997-2016 and the seismicity data of the Eastern Mediterranean from IRIS bulletin ( http://ds.iris.edu/ds/nodes/dmc/data/types/events/ ).

  in the Mirone manual software, TINTOL (NSWING) code to perform tsunami modelling of propagation and inundation. The code models the tsunami propagation by using the bathymetry grid (as used in this study of gebco data 2014 of 30 arc seconds) and identify the initial deformation by the Okada (1985) model. The code used the linear theory in deep sea and with the shallow sea theory and on land with constant grid length in the whole region. The computation of tsunami wave velocity was done according to the shallow water equation v = where g is the gravity acceleration and h is the water event was examined to study the effect of location, direction, travel time and height towards the Egyptian Coast. Computed tsunami features such as travel times and wave height distribution are calculated, which are useful in the evaluation of the tsunami hazard. This is done using the estimated flood zones and comparison with the tsunami wave height and deposition to help determine the intensity of tsunamigenic earthquakes and their impact on the northern Egypt coast. Paleo-tsunami studies in northern Egypt are important because of the following reasons:-1) the region includes archaeological monuments found along the Egyptian coast like the Citadel of Qaitbay, Ruins of the Temple of the King, the Pharaoh Ramesses II (1200 BC) temple, the Rommel's hideout and the Library of Alexandria; 2) the development of new Cities along the Egyptian coast like New EL Alamein city and 3) the construction of a nuclear power plant in the area of El-Dabaa on the Egyptian coast. As the Egyptian coastline was badly damaged in the past, a hazard assessment and mitigation plan need to be developed for the protection of these sites from future tsunamis.

  missing and 532,898 persons displaced (USAID 2005). Ishimura et al.(2015), studied historical and paleotsunami deposits during the last 4000 years including deposits of the 2011 Tohoku tsunami. In their study, they used canal trenches which were 2 m deep and 300 m from the shoreline. The 2011 Tohoku tsunami had a maximum runup height of 26-29.4 m at Koyadori and minimum run-up height of 5.8-8.9

  [START_REF] Polonia | Mediterranean megaturbidite triggered by the AD 365 Crete earthquake and tsunami[END_REF] examined the paleotsunami tributaries in cores in Malta and western Crete Island. Their results depend on the changes of sedimentology and geochemical pattern in the stratigraphy of cores. The radioactive dating shows the presence of the 21 July 365 in the Malta and western Crete cores.

Fig. 5 :

 5 Fig. 5: Philips PW 1730 X-ray diffractometer used in the study.

1 ) 3 )

 13 Along the central Mediterranean rise, a general NE-SW to NNW-SSE compression trend exists in the outer part of the Hellenic Arc. It starting south of Zante and up to the coast of Turkey, is deforming through high angle reverse mechanisms. These faults mechanisms are responsible for the rapid uplift in the western coast of Crete 2) At the inner part of the Hellenic Arc, a narrow zone is developed along the whole extent of the Arc which is characterized by the presence of N S trending normal faults. This zone consists of an accretion prism up to the volcanic arc and is deforming by normal faulting with the T-axes having an almost E W direction. The normal faulting does not occur deeper than 35 km and is underlain by active shortening result from gravitational collapse. Along-arc extension continuous up to the coast of southern Turkey following the Taurides Mountain range. The back-arc area, starting north of the volcanic arc deforms by normal faulting where the T-axes have the N S direction at the Aegean Sea. The western coast of Peloponnese is deforming by strike-slip faulting where, if the NE SW trending planes are selected as the fault planes, then this faulting is parallel to the Cephalonia strikeslip fault and the sense of strike-slip motion is dextral (Fig. 7, Scordilis et al., 1985). The island of Crete represents an emergent high at the fore-arc of the subduction zone, indicating the transition between the African and Eurasian plates. The Hellenic arc is associated with moderate arc-parallel extension and strong compression perpendicular or oblique to it. Three successive fault groups occupy the Crete Island. The first represents E-W trending faults of kilometric scale, mainly cutting the basement rocks or bound basement rocks and Miocene sediments. The second group consists of large and moderate scale N-S striking faults, cutting the previously mentioned group. The third group comprises kilometric scale faults striking NE-SE, which appear to be youngest faults occurring on

Fig. 7 :

 7 Fig. 7: Summary of the distribution of focal mechanisms for earthquakes along the Hellenic trench constructed based on[START_REF] Cavazza | The TRANSMED Atlas. The Mediterranean region from crust to mantle geological and geophysical framework[END_REF][START_REF] Billi | Recent tectonic reorganization of the Nubia-Eurasia convergent boundary heading for the closure of the western Mediterranean[END_REF][START_REF] Benetatos | Focal mechanisms of shallow and intermediate depth earthquakes along the[END_REF]

Fig. 8 :

 8 Fig.8: Morphotectonic map of the Mediterranean with major, simplified geological structures offshore constructed based on bathymetry data of ETOPO1 (1 min arc-minute global relief model of Earth's surface; https://www.ngdc.noaa.gov/mgg/global); Reilinger et al., 2006).

Fig. 9 :

 9 Fig. 9: Map of the Egyptian continental margin with major simplified geological structures onshore and offshore based on tectonic tectonics structures elements from (Abdel Aal et al. 1994; Egyptian geological map EMRA, 2008; bathymetry data of ETOPO1 (1 min arcminute global relief model of Earth's surface; https://www.ngdc.noaa.gov/mgg/global/)).

  using 2D seismic profiles; the tectonic history of northern Egypt is divided into three main phases based on 2D seismic profiles wells data: The first phase, a thick wedge of Early and Middle Mesozoic sediments was deposited. The southern edge of this sequence is north of a late Paleozoic and Early Mesozoic E-W trending faulting zone which bisects the Sinai (Abdel Aal et al., 1992)and bounded the intracratonic Abu Gharadig basin in the central northwestern desert. The deep structures in the Nile Delta show that the hinge line bisected the delta parallel to preexisting E-W fault trends (Fig.13). During the Triassic and Jurassic, the opening of Tethys

  fault trends during Late Eocene-Miocene. The first trend is the Gulf of Suez NNW trending normal faults observed in the central Nile Delta. The second is the NNE faults trend related to the development of the Gulf of Aqaba rift which is formed from the Miocene up to recent by left lateral oblique slip movement. The third is the NS Baltim fault (Fig.9,13) trend which is thought to be formed by rejuvenation and reactivation of the older pre-Tertiary structure during the early Miocene[START_REF] Aal | Tectonic evaluation of the Nile Delta, its impact on sedimentation and hydrocarbon potential[END_REF]

  Fig. 10: Tectonic geological map of Sinai constructed based on Egyptian geology map EMRA (2008) using ArcGIS map version 10.2 Software.

Fig. 11 :

 11 Fig. 11: Tectonic geology map of the northwestern Desert constructed based on Egyptian (geological survey EMRA, 2008) using ArcGIS map version 10.2 Software.

4 ) 5 )

 45 Fig. 13: Tectonic geological map of Nile Delta based on compiled structures from (Abdel

  Fig. 31 a, and b; Hartman et al., 2014 shows that the Gulf of Aqaba has dominant left lateral strike-slip motion along the main faults parallel to the main axis of the Gulf, and normal slip along the traversing faults. From north to south,

Fig. 14 :

 14 Fig. 14 : (a) Generalized tectonic settings of the Aqaba by Hertman (2014). The Evrona and Timna basins are mapped from bathymetric, gravimetric and magnetic data[START_REF] Frieslander | The structure of the Dead Sea transform emphasizing the Arava, using new geophysical data[END_REF][START_REF] Brink | Magnetic character of a large continental transform: An aeromagnetic survey of the Dead Sea Fault[END_REF]). (b) Schematic models of the deep section of the basins[START_REF] Ben-Avraham | Structural framework of the gulf of Elat (Aqaba), northern Red Sea[END_REF][START_REF] Brink | Anatomy of the Dead Sea Transform; does it reflect continuous changes in plate motion?[END_REF]).

  are also based on the Al-Suyuti (1445 1511) work titled "Kashf El-Salsala and wasf El-Zalzala the sequential discovery from the description of earthquakes between 712 AD and 1499 AD (translated into English by Springer in 1843 from the Arabic manuscript of the National Library of Paris).

Fig. 15 :

 15 Fig. 15: Historical earthquakes in Eastern Mediterranean and North Egypt (see historical earthquakes references Table13of the historical earthquakes in Appendix A).

  history of instrumental recording of earthquakes started in Egypt as early as 1899 at Helwan (Hlw) by an E-W component Milne Shaw seismograph. While another N-S component of Milne Shaw and vertical component of Galitzin-Willip seismographs were initiated in 1922 and 1923, respectively. In 1955, another set of short period Sprengnether seismographs were also added. In May 1962, the system was replaced by the Benioff short period and Sprengnether long period seismographs with the photographic recording system and Helwan became one of the World Wide Standardized Seismograph Network (WWSSN) stations. In December 1972, a Japanese three-component short period component seismograph system with analogue recording system was installed. In 1975, another three permanent seismological stations with photographic recording system were installed at Aswan, Abu Simbel and Mersa Matrouh. These stations have three component short period seismometers. In 1990, a broadband station (KEG) was installed at Kottamyia as a part of the Mednet project. In cooperation with the International Institute of Seismology and Earthquake Engineering (IISEE) of Japan, the National Research Institute of Astronomy and Geophysics (NRIAG) has installed a network of 10 telemetered seismic stations, which was operational in August 1994 around the southern part of Gulf of Suez. All these stations have the same seismograph system which consists of L4C (Mark product) vertical component seismometer. Only one station of this network was equipped with a horizontal component. In 2008, NRIAG started the construction of strong motion network (Fig.16) along the highly populated Nile Delta in the northern Egypt. These strong motion network reached 10 stations with the end of 2016.

Fig. 16 :

 16 Fig. 16: The Egyptian National Seismological Network (ENSN) and the Nile Delta strong motion stations in Egypt

  The NW-SE to E-W structures are in agreement with the coseismic surface features and related liquefaction features observed near the earthquake epicenter and mainly in the late Quaternary alluvial Nile deposits. d-The November 22, 1995, Gulf of Aqaba earthquake (Ms = 7.2)

  Fig. 17: The seismicity

  collected. These catalogues include the European Mediterranean Net (Med Net) of the National Institute of Geophysics and Volcanology of Rome, ZUR-RMT of the Institute of Technology of Zurich (ETHZ), German Research Centre for Geosciences (GFZ).In the following paragraphs, I will present and discuss the focal mechanisms solutions and fault trending in the active tectonic zones of Egypt which include the Egyptian continental margin, Dahshour zone, and Cairo-Suez area, Northern Gulf of Suez, South Gulf of Suez, and Gulf of Aqaba.3.5. a. Egyptian continental margin19 focal mechanisms solution of magnitude M L works were collected (Fig.18, see references to the focal mechanism data Tables1 and 2in Appendix A). The results from focal mechanisms show two types of tectonic regimes: the first group of mechanisms is represented by NW Oblique (normal dextral) faults (blue beach ball); and the second is compressive, represented by E-W to ENE (reverse sinistral) faults (red beach ball).The largest event occurred in the Egyptian continental margin on September 12, 1955, with Ms 6.7(Costantinescu et al., 1966) in the continental shelf of the Nile Delta. This event indicates a strike-slip faulting mechanism with a considerable reverse component along an NE-SW or ESE-WNW striking plane(Korrat et al., 2005). The ESE-WNW striking plane yields a right-lateral motion whereas the NE-SW fault plane indicates left-lateral offset. The October 19, 2012 event occurred at 03:35:11.2, (GMT) with Mb 5.1 according to the Euro-Mediterranean Seismological Centre (EMSC) and represents the second largest offshore significant seismic event that occurred within 57 years in the continental margin of the Nile delta.

Fig. 18 :

 18 Fig. 18: Focal mechanisms of 19 events with M L

Fig. 19 :

 19 Fig. 19: Focal mechanisms of 19 earthquakes M L Tables 2 and 4 in Appendix A).

  Fig. 20: Focal mechanisms of 12 earthquakes with M L -Suez area (see reference Tables5 and 6in Appendix A).

  These solutions are characterized by normal faulting mechanisms. The nodal planes have directions close to NW-SE to NNW-SSE. The rest of solutions exhibit either oblique or pure strike-slip motion. The sense of strike-slip component along the NW-SE trends were a subject of debate among previous studies.[START_REF] Garfunkel | The tectonics of the Suez Rift[END_REF] and[START_REF] Chenet | Décollement and extensional tectonics on the eastern margin of the Suez rift[END_REF] supposed a left lateral movement while[START_REF] Maamoun | Neotectonic and seismic regionalization of Egypt[END_REF][START_REF] Moustafa | Transfer zones with en echelon faulting at the northern end of the Suez rift[END_REF][START_REF] Moustafa | Assessment of ground motion variation for seismic hazard mitigation in the vicinity of Cairo metropolitan area[END_REF] assumed a right lateral movement.The interaction of the northern tip of the Red Sea -Suez rift with the Mediterranean margin, suggests a high strength of oceanic lithosphere and the start of seafloor spreading south of the Arabian plate in the Gulf of Aden,[START_REF] Moustafa | Transfer zones with en echelon faulting at the northern end of the Suez rift[END_REF][START_REF] Moustafa | Rejuvenation of the eastern Mediterranean passive continental margin in northern and central Sinai; new data from the Themed Fault[END_REF][START_REF] Moustafa | Assessment of ground motion variation for seismic hazard mitigation in the vicinity of Cairo metropolitan area[END_REF] attribute the northern termination of the Suez rift to the transfer of slip into the E-W faults pre-rift (Suez-Cairo faults) in the northeastern Desert. They also indicate an ending of the NNW-SSE faults along the western Sinai against the E-W themed fault. 3.5.e. South Gulf of Suez zone The largest two significant earthquakes of Shadwan Island occurred on March 31, 1969 (M L = 6.7) and June 28, 1972 (M L = 5.0) along the southern part of the Suez Gulf. These solutions indicate normal faulting mechanisms with NW-SE with strike-slip mechanism. Moustafa 2001 have identified some structural trends with a left lateral strikeslip motion in the southern Gulf of Suez zone. The 29 collected focal solutions in the southern Gulf of Suez of M L Appendix A Tables

Fig. 21 :

 21 Fig. 21: Focal mechanisms of 15 earthquakes with M L magnitude in the northern of Gulf of Suez (see reference Tables 9 and 10 in Appendix A for the focal mechanism solutions).

Fig. 22 :

 22 Fig. 22: Focal mechanisms of 29 earthquakes M L magnitude in south Gulf of Suez (see reference Tables11 and 12in Appendix A for focal mechanism solution).

  2; Hussein and Abu Elenean 2008) in this region is that of November 22, 1995. The CMT-Harvard fault plane solutions of the November 22, 1995 large event give normal fault mechanism with a slight strike-slip component along the nodal planes trending NNE to N-S and NW. The NNE to N-S nodal planes show slight left lateral component appears to be consistent with the mechanisms of the two foreshocks of August 3, 1993: M L = 6 at 12:43 and M L = 5.7 at 16:33 respectively. These three large events are shown as black beach balls in Fig. 23 (see Appendix A Tables

  Fig. 23: Focal mechanisms of 36 earthquakes with M L magnitudes in Gulf of Aqaba (see referenceTable 8 in Appendix A for the focal mechanisms solutions)

  for a detailed description of the principles and procedures of fault-slip analysis and paleo-stress reconstruction using focal mechanism data. In this work, we used the Stress Tensor inversion software, version 5.8.5 (Windows version; last updated on July 27, 2016. It allows us not only to obtain the first estimation of the principal stress axes orientations and also estimate the stress ratio R and stress regime kinematics and to filter out the focal mechanisms that may not be compatible with slip vector d

Fig. 24 )

 24 . The inversion in Trend A show normal faulting N39.2E with strike fault component including the Rosetta trend and extend to Qattara-EL Alamein trend and the value of stress regime index is 0.67. The data set of eight focal mechanisms events for Trend B (Table 3, Fig. 25). Trend B show compressive with shmax. = 79º by trending NE-SW reverse faulting and with stress regime index value = 2.12. N=is the number of data explained by stress tensor Nt the total population of fault solutions : mean slip deviation for all focal mechanisms used shmin. minimum shear Shmax. maximum shear Shmin. minmum shear These data and results of Trend A and Trend B covered the stresses in the Rosetta trend and reveal the stress distribution from Alexandria to El Alamein margin. The Tamash and Baltim trend in the continental margin is characterized by low-level seismicity data. There are two main Sh max orientations observed in oil wells above the Messinian evaporates in both trends. The stress orientation of the continental margin in the front of the Nile Delta observed from 11 wells (Tingay et al., 2011) indicates a dominate N-S to NE-SW Sh max orientation and a secondary E-W to NW-SE orientation observed in six wells in the central region. These trends are also observed in Fig. 32.

Fig. 24 :

 24 Fig. 24: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at continental margin Zone A, Trend A (see Table3).

Fig. 25 :

 25 Fig. 25: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at continental margin Zone A, Trend B (see Table3).

  Fig. 26). The inversion of focal mechanisms in this zone yields an extensive stress regime characterized by E-W and WNW-SES trending faults with N25ºE Shmechanism with a strike -slip component. The rotational optimization of actual faults shows quality index A. These results agree with Hussein et al.(2013).

  Fig. 26: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at Dahshour Zone Zone B (see Table3).

Fig. 27 :

 27 Fig.27: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at Cairo-Suez zone, Zone C (see Table3).

  Fig. 28: Rotational optimization method of the present day stress tensor deduced from focal mechanisms data at Northern Gulf of Suez, Zone D (see Table3).

  Fig. 29: Parameters of the present day stress tensor deduced from focal mechanisms data at Southern Gulf of Suez, Zone E (see Table3).

Fig. 30 :

 30 Fig. 30 : Parameters of the present day stress tensor deduced from focal mechanisms data at

Fig. 31 :

 31 Fig. 31: Parameters of the present day stress tensor deduced from focal mechanisms data at

  counterclockwise rotation with respect to Africa plate fixed with tangential velocities of 2 mm/yr. This proposed model predicts a small extension (from 0 to 2 mm/yr moving from north to south) in the Gulf of Suez with left-lateral strike-slip motion along the Gulf margin of 1 mm/yr. They estimated the strain rate field by velocity interpolation on a regular grid equal to rate of 40-50×10 -9 /yr in the Sea, the Nile Delta region with the largest deformation along the Dead Sea Transform fault, where the shear prevails with strain rate values up to 90×10 -9 /yr[START_REF] Pietrantonio | Kinematics of the Suez-Sinai area from combined GPS velocity field[END_REF]. The direction of the main strain rate axes is consistent with the direction of the Red Sea opening and with the left-lateral shear zone along the Dead Sea fault.The stress results from this study in northern Egypt indicate that this tectonic domain is under an extensional stress regime. This stress regime is presently dominating in most of Egypt as normal with minor strike faults of extension trending N to NNE. The northern parts of Egypt have been extensively explored for hydrocarbons, particularly in the Gulf of Suez, Nile Delta (offshore and onshore), and the basins of western Desert. A small number of exploratory wells have also been drilled in the Red Sea and southern Nile Valley. Therefore, abundant material exists for the development of breakout and well-bore stress field studies.[START_REF] Bosworth | Late Quaternary reorientation of stress field and extension direction in the southern Gulf of Suez, Egypt: Evidence from uplifted coral terraces, mesoscopic fault arrays, and borehole breakouts[END_REF] analyzed sub-Miocene salt breakouts in wells from the southern Gulf of Suez and found a consistent N75°W orientation for SH (one small sed additional wells and came to a similar conclusion with SH N70°W, although his analysis of earthquakes gave ENE-WSW SH with a fairly broad range of uncertainty. The breakout results are somewhat surprising, as they indicate a propensity for nearly N-S shallow crustal extension highly oblique to the axis of this rift. This is supported by the occurrence of several large recent earthquakes in the southern Gulf of Suez that showed normal movement and NNE-SSW striking T-axes. The breakout data from the southern Gulf of Suez suggest that the stress field of Central Africa Intra Plate (the CAIP) extends from Congo to Sudan to north most Egypt and Libya where the maximum horizontal stress is E-W and it is related to far effects of ridge in the Atlantic and Indian Ocean (Bathworth 2008). The stress regime of CAIP is a mixture of strike-slip and thrust faulting in the south and strike-slip and normal faulting in the north.

  Fig. 32 summarizes the stress distribution in northern Egypt and the Eastern Mediterranean region obtained from the stress inversions of this study. In addition to the stresses determined from the oilfield boreholes and the data of the World Stress Map

Fig. 32 :

 32 Fig. 32: Stress map of the North Egypt and Eastern Mediterranean region (this map is constructed based on data from the calculated stress inversion in this study, tensor and world stress data (http://www.world-stress-map.org/), Egyptian geological map (EMRA, 2008),Reilinger et al. 2006, Saleh and[START_REF] Saleh | New constraints on the Nubia-Sinai-Dead Sea fault crustal motion[END_REF].

Fig. 33 :

 33 Fig. 33: The location map of the studied areas in northern Egypt.

Fig. 34 :

 34 Fig. 34: The location and geomorphology landforms map in the studied area after Raslan (1995).The geomorphology of the area characterized by geomorphologic features include the following :

Fig. 35 :

 35 Fig. 35: Sand dunes along Mediterranean coast west Mersa Matrouh.

Fig. 36 :

 36 Fig. 36: Large boulders in Kefr Saber.

Fig. 37 :

 37 Fig. 37: Large boulders in Ras EL Hekma.

Fig. 41 :

 41 Fig. 41: The end of core tube.

Fig. 39 :

 39 Fig. 39: Pumping machine to discharge the underground water.

Fig. 40 :

 40 Fig. 40: Photo core dug using Cobra instrument.

Fig. 42 :

 42 Fig. 42: The preparation of core.

  i. Kefr Saber siteThis site is located ~32km west of Marsa-Matruh city in an area characterized by a lagoon depression protected from the sea by 2 to 20 m high sand dunes (Figs.44 a, b and c).The area also shows big rocky boulders rich in Dendropoma along the nearby shoreline that testify for past tsunami deposits. Five trenches dug in June 2014 (Fig.44 c). The trenches were dug perpendicular to the E-W trending coast in a dry lagoon.The sizes of trenches are ~2 x 1 m and ~1.5m deep. The trenches dug to figure out the deposits and find the geological evidence for the tsunami deposits. The detailed description and photography were done in the field (seeFigs. 45, 46, 47, 48 and 49).

Fig. 44 :

 44 Fig. 44: a) Coastal zone at Kefr Saber rich in boulders, b)Dendropoma fossils rich in the boulders, and c)the location of the five trenches P1 to P5 at Kefr Saber.

Fig. 45 :

 45 Fig. 45: Description of trench no.1.The arrow reflects tsunami layer 1 which is rich in broken shell fragments.

Fig. 46 :

 46 Fig. 46: Description of trench no.2.The arrow reflects tsunami layer 1 which is rich in broken shell fragments.

Fig. 48 : 1

 481 Fig. 48: Description of trench no.4.The arrow reflects tsunami layer 1.

Fig. 51 :Fig. 54 :

 5154 Fig.51: Description of core no.1 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 166 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 3) and organic matter are interpreted as deposits of tsunami origin

Fig. 55 :

 55 Fig. 55: Description of core no.4 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 435 m from the shoreline 166 m from the shoreline. It reveals 2 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 3) and organic matter are interpreted as deposits of tsunami origin.

Fig. 56 :

 56 Fig. 56: Description of core no.5 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 490 m distance from the shoreline and the sedimentary succession does not show any possible sedimentary high-energy sedimentary layer of tsunami origin.

Fig. 58 :

 58 Fig.58: Description of core no.7 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 273 m from the shoreline and reveals

Fig. 61 :

 61 Fig.61: Description of core no.10 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 245 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter.

  in Appendix E) it reflects multiple effects that a tsunami wave can have on deep sea and coastal sedimentation in a Mediterranean type basin. Moreover, the transportation of samples in depths, not its real depths due to high energy wave current resulted from tsunami or old age storm. The C 14 isotopic dating of tsunami deposits has allowed the correlation with known historical earthquakes of the Eastern Mediterranean region. Compared with other Mediterranean coastal regions, our results show the identification of one tsunami stratigraphy markers in Kefr Saber and four tsunami stratigraphic deposits at the El Alamein site.The chronology of sediments in cores in El Alamein was constructed with the Bayesian simulation provides the dating of the four tsunami deposits using the Oxcal software Bronk-Ramsay (2001). The tsunami layers are comparable with the four historical events :simulated tsunami event (W, 1600 BC(Santorini tsunami ?) ;simulated tsunami event (X, 21July365) ; (simulated tsunami event Y, 8 August 1303) ; (simulated tsunami event Z, 24 June 1870), as shown from the probability density function (PDF) of the Oxcal program as shown in Fig. 66. One recognized stratigraphic tsunami layer at Kefr Saber compared with the 21 July 365 tsunami (simulated tsunami event X) as shown in Fig.65

Fig. 65 :

 65 Fig. 65: Composite section for the trenches in Kefr Saber.

Fig. 66 :

 66 Fig. 66: Composite section for the cores in El Alamein.

  Mediterranean region that affected northern Egypt are triggered by large earthquakes(Papadopoulos et al., 2014) but the possibility of landslide tsunami associated with local earthquakes[START_REF] El-Sayed | Seismicity and seismic hazard in Alexandria (Egypt) and its surroundings[END_REF] Yalciner et al., 2014). However, the effects of landslide tsunami are limited to the nearby coastline as shown by the recent examples of landslide tsunamis in the Mediterranean associated with the eruption of Stromboli volcanic eruption of 30 December 2002[START_REF] Tinti | The 30 December 2002 landslide-induced tsunamis in Stromboli: sequence of the events reconstructed from the eyewitness accounts[END_REF].Egypt is one of these countries that have experienced strong tsunami impacts in the past (e.g., 21 July 365 and 8 August 1303 AD tsunamis) and has geological records along coastlines. The Eastern Mediterranean area is characterized by very complex tectonics that can be generally described in the frame of the convergence of the African plate towards Eurasia. The problem is particularly urgent for the Mediterranean countries that are known to have been affected by tsunamis in the past, several of which had catastrophic size and impacts. A detailed description of the seismotectonic processes responsible for tsunamis taking place in the Eastern Mediterranean region and possible tsunami sources are described in Chapter III & Chapter IV. The record of paleotsunami events presented in the previous chapter indicates the location of two large historical tsunami events of 21 July 365 and 8August 1303.

Fig. 67 :

 67 Fig. 67: Bathymetry data from Gebco (2014) (30 arc seconds) with the location of the fault rupture zone (box) along the Hellenic subduction between Crete and Rhodos as the seismic source for the first scenario.

Fig. 68 :

 68 Fig. 68: Initial wave of the eastern Hellenic arc scenario (see seismic source parameters in Table4and location in Fig.67).

Fig. 69 :

 69 Fig. 69: Wave propagation at min 33 after the tsunami was triggered by an EH source.

Fig. 70 :

 70 Fig. 70: The wave height after 50 minutes of wave propagation in the eastern Hellenic arc scenario. Wave heights of 10 m reach northern Egypt.

Fig. 71 :

 71 Fig. 71: The wave height after 66 minutes of wave propagation in the eastern Hellenic arc scenario. Wave heights of 7 m reach northern Egypt.

Fig. 72 :

 72 Fig. 72: The wave height after 80 minutes of wave propagation in the eastern Hellenic arc scenario. Wave heights of4 m reach northern Egypt.

Fig. 73 :

 73 Fig. 73: Bathymetry data from Gebco (2014) (30 arc seconds) with the location of the fault rupture zone (box) along the Hellenic subduction west of Crete as the seismic source for the second scenario.

Fig. 75 :

 75 Fig.75: The wave height after 33 minutes of wave propagation in the Western Hellenic arc scenario.

Fig. 77 :

 77 Fig.77: The wave height after 100 minutes of wave propagation in the Western Hellenic arc scenario.

  have the highest wave height of 9.4 m at Alexandria in the western Hellenic arc scenarios. Simulated results of Shaw et al., (2008) offshore of Alexandria shows wave heights of ±0.6 m which is in agreement with my results at Alexandria in case of Western Hellenic arc scenario. The first arrival time of my simulations is similar with Pagnoni et al. (2015), especially for Alexandria and Matrouh in the eastern Hellenic scenario.

  Fig.79 a. Synthetic tide gauge at Kefr Saber in case of west Hellenic scenario

  . The Cyprian arc connected to the Hellenic arc in the West, and Dead Sea Transform Fault and East Anatolian Fault in the East. A northward subduction of oceanic material related to the African Plate beneath the Anatolian Plate indicates the convergent mode along the western segment of the Cyprian arc (Ben Avraham et al.,1988). Secondly, six seismic active zones are identified from the study of seismicity and tectonic geology in the north of Egypt. The six zones are the Egyptian continental margin, Dahashour zone, Cairo-Suez zone, Northern Gulf of Suez, Southern Gulf of Suez, Gulf of Aqaba. My works include the collecting of fault plane solutions of earthquakes in the six active seismic zones of northern Egypt and calculating the stress inversions of the fault parameters in these active zones using the Tensor software version 5.8.5 (Windows version; last updated on 27/07/2016, http://www.damiendelvaux.be/Tensor/WinTensor/wintensor.html). The first active zone in the north Egypt; is the Egyptian continental zone (A) which was located to the south of the Mediterranean Sea ridge behind the Herodotus abyssal plain where the sea floor is occupied by the Nile Deep-Sea fan, Eratosthenes Seamount, and Herodotus basin. It represents a transition zone between the continental oceanic crusts where the stress field changes from dominant tension inland of Egypt to dominant compression along the Hellenic Arc. The tectonic framework and structural pattern of the Egyptian continental margin are the results of the interplay between three main fault trends:

2 ,with

 2 Mb 5.1 according to the Euro-Mediterranean Seismological Centre (EMSC). The EL Alamein recent earthquake occurred on September 03, 2015 (M L = 4.5) and the fault of El Alamein was considered as a continuation of AL Qattara EL Alamein fault zone which extends from the Rosetta area in the continental margin. The results of 19 collected focal mechanisms in the Egyptian continental margin (Zone A, trend A, B (Fig.18) and adjacent area show two types of tectonic regimes: The first group of mechanisms is represented by NW Oblique (normal dextral) faults and the second is compressive represented by E-W to ENE (reverse left-lateral) faults. The stress inversion of in our study of the Egyptian continental margin zone is classified in two main trends A, B. The stress inversion of trend A of 10 collected focal mechanism with normal faulting with strike-slip components stress regime index R ' = 0.67 of the Tensor quality is B. The trend A represents the stresses in the Rosetta trend and continued with the stress distribution from Alexandria to El Alamein margin (Qattara EL Alamein Ridge). The stress inversion of trend B included 8 focal mechanism solutions. This trend represents the stresses parallel to the Rosetta trend until Mars Matrouh area. The stress regime index R' of trend B is 2.12 and shows pure compressive (TF) with Tensor Quality B. The Tamash and Baltim trends in the east of continental margin are characterized by low-level of seismicity data. The stress orientation from breakout study of Tingay et al. (2011) using 11 wells in the front of the Nile Delta indicates a dominant N-S to NE-SW Sh.

  calculated in the Dahshour zone results from 19 focal mechanisms in this zone yielding extensive stress regime characterized by NE-SW trending faults with N25°E Shmin. The stress index R' is 0.69 with consistent with normal faulting and strike-slip component; the Tensor quality is B. These results agree with stress inversion calculated byHussein et al. (2013).The third active zone in the northern Egypt is the Cairo Suez Zone(C) located West the Gulf of Suez following the Cairo Suez road and north of the Eastern Desert. The two large earthquakes events occurred on September 29, 1984, M L= 4.5 and 29 April 29, 1974 of M L =4.6. Most of the mechanisms recorded mainly show pure normal faults and oblique source of the normal component with E-W and NWN-SES and NW-SE trends in accordance with the general strike direction of exposed faults. The stress tensor inversions are applied to 12 focal mechanisms events for the Cairo-Suez zone. The inversion of focal mechanisms of earthquakes in this zone yields extensive stress regime characterized by NE-SW trending faults with N18.7°E Sh-min. The stress index is R'=0.69 representing a normal fault with strike faults (transtensive) component with Tensor quality A. The rotational optimization of actual faults shows quality A stress tensor. The fourth active zone located in the northern Egypt is north of the Gulf of Suez zone (D) and it is considered as a Neogene continental rift which has evolved as one arm of the Sinai triple junction together with the Gulf of Aqaba and the Red Sea. Dagett et al. (1986) considered it as an active zone in spite of no large earthquakes occurred in this zone. The 15 collected focal solutions are characterized by normal faulting mechanisms. The nodal planes have directions close to NW-SE to NNW-SSE. The rest of solutions exhibit either oblique or pure strike-slip motions. 14 focal mechanisms events for the northern Gulf of Suez are applied to stress tensor inversions. The inversion of focal mechanisms of earthquakes in this zone yields pure extensive stress regime characterized by NE-SW trending faults with N44E Sh-min. The stress regime index is R'=0.64. This value is consistent with a normal faulting and extensional regime, where the rotational optimization of the actual faults show Tensor quality A. The fifth active zone in the northern Egypt is the southern Gulf of Suez (E). Two largest earthquakes are recorded in this zone which is the Shadwan Island earthquakes on 31 March 1969 (M L =6.1); and 28 June 1972 (M L =5.0). The 29 collected focal mechanism normal faulting mechanisms with NW-SE trends. The stress tensor inversions were applied to 28 focal mechanisms of the south of the Gulf of Suez. The inversion of focal mechanisms of earthquakes in this zone yields extensive stress regime characterized by NE-SW trending faults with N27.8°E Sh-min. The stress regime index is R'=0.51 and Tensor quality A. The sixth active zone in northern Egypt is the Gulf of Aqaba zone (F, G subzones) considered as a source region of intense activity which forms the main tectonic plate boundary between Africa (Sinai) and Arabia. The largest recorded and strongest earthquake (Mw=7.2) occurred on November 22, 1995. The 36 focal solutions show normal faulting with left-lateral strike-slip component or strike-slip fault with minor normal component, while some events reflect normal faulting mechanism. Most of the events show T-axes approximately in the NNE to N-S and NW direction. The stress tensor inversions were applied to 7 focal mechanisms events for Gulf of Aqaba zone subzone F. This zone is located north of 29° latitudes. The inversion of focal mechanisms in this zone shows normal faulting, where the stress regime index is R =0.89, N72.3ºE for Sh-min and Tensor quality are A. The subzone G is located south of 29° latitudes, where the stress tensor inversions are applied to 27 focal mechanisms. The stress regime index is R'=0.98, with N 59.3° E Shmin and Tensor Quality A. The inversion of focal mechanisms of earthquakes in this zone yields a normal faulting with strike-slip component. To complete the picture of the deformation and direction of stresses, I compiled: a) GPS velocity vectors to estimate the strain rate (Reilinger et al., 2006); b) stress inversion calculated in this study using Tensor program version 5.8.6 of 23/11/2016 (Delvaux et al., 2010); c) the stresses calculated by petroleum boreholes breakout studies (Tingay, 2011); d) the stresses of the world stress map (http://www.world-stress-map.org/) in the Eastern Mediterranean region and northern Egypt to have complete picture of the present-day stress distribution. The main conclusion of stress results shows that the whole northern Egypt is under extensional stress regime except for the Egyptian continental margin which shows compressive trends. This stress regime is presently operating in most of the northern Egyptian regions as normal faulting and strike-slip with Shmin trending N-NNE.

  Three successive field works were carried out in June 2014, August 2015, and October 2015 in the northern Egyptian coast. The aim of this field works was to 1) investigate the geology and geomorphology of the north coast of Egypt. 2) To study the successive sequence of the stratigraphy of the in the both EL Alamein and Kefr Saber selected sites and 3) characterize the age of the possible tsunami layers depend from the carbon dating chronology and tsunami signatures.For the paleotsunami site selection, geomorphological and topographic setting criteria were taken into accounts as well as accessibility in order to avoid urbanization and artificial soil reworking. The geomorphological criteria are:The first is the presence of large boulders noticed along the coastline in northern Egypt in localities such as Ras El Hekma Ras ELAlam Rum Mersa Matrouh -East Mersa Matrouh (Kefr Saber) with rich content of Dendropoma fossils. The calibrated dating of Dendropoma sample at Kefr Saber is 940-1446 AD which may be correlated with a strong and high (> 5m) wave to Kefr Saber coast possibly during that8 August 1303 tsunami. This result coincides with that ofShah-Hosseini et al.,(2016) along the same coastline.The second geomorphological criteria are the presence of coastal sand dunes along the Egyptian Coast.They are composed of loose white oolitic carbonate sands washed from the degradation of oolitic coastal dune ridges with height from 2 to 20 meters. Behind these sand dunes, the third geomorphology criteria are the lagoons or salt marshes found between dissected ridges with sometimes a lower elevation below sea level as West of Marsa Matrouh.

  Two composite sections were constructed to summarize the stratigraphic logs and recognized tsunami layers in Kefr Saber and EL Alamein site with chronology and date simulation of paleotsunami historical events 1600 BC, 21 July 365, 8 August 1303 and a more recent tsunami event on 24 June 1870.The stratigraphic logs of the trenches in Kefr Saber show mainly one tsunami layer of mixed sand and gravel, and broken shells at depth ~ 35 cm with thickness 20 cm comparable with the 21 July 365 tsunami deposits. The cores in El Alamein show four main layers characterized by fine and coarse sand mixed with broken shells fragments that indicate the occurrence of high-energy sedimentary deposits in the coastal lagoon environment.

  150 minutes. The wave height reached 4-10 m at the arrival time 33 minutes on the Libyan coast. The wave arrives at the Egyptian coast after 66 minutes with slightly low wave height compared with the wave on the Libyan coast. The wave's height arrives at the Egyptian coast with 0.8 1.7 m at Kefr Saber and with 0.4 -0.8 m wave height at El Alamein after 100 minutes. The tsunami waves cover the entire Egyptian coast after 150 minutes from the western Hellenic arc source scenario.

First, it was

  not possible the seismotectonics study to do detailed field investigations of the active seismic zones and active Quaternary faults. However, field to Cairo-Suez zone and EL Alamein faults were carried out as primary investigations in October 2015and reconnaissance were conducted. Neverless, there is no problem to carry out detail field measurements for the El Alamein active quaternary fault for the future perspective. Secondly for paleotsunami study, a) Field investigations are planned at the site of sinking Thonis Heracleion city, an old Egyptian historical city located in the Canopic mouth of the Nile, 32 Km northeast from the Alexandria coast. This city was supposedly flooded apparently following a major tsunami b) Complete the coring and previous investigations in other sites located from Kefr Sabr to Salloum to determine a possible inundation of the historical tsunami inland along the northern Egyptian coast. c) Creating a possible worst scenario for the arrival time and height of tsunami waves for the strategic projects constructed on the Egyptian coast such as the New El Alamein city and the Egyptian nuclear power plant. My recommendations are1) the minimum arrival time for the tsunami waves to arrive at the Egyptian coast being 30 minute in case of the Eastern Hellenic arc scenario, and 66 minutes in case of Western Hellenic arc this leaves enough time to take protective measures and send alarms to the civil defence and Egyptian coast and save people lives. The following Table 8, Fig. 80 summarizes the data for decision makers. The warning messages are requiring a close cooperation with the Turkish and Greek Centers of Tsunami studies

Fig . 80 :

 80 Fig .80: The message types in case of local, regional, basin-wide with earthquakes magnitude.

Fig. 2

 2 Fig. 2 Strike and dip direction of fault plane in the hemisphere stereographic projections.

  distinguishes three possible combinations of magnitudes of principal stresses: the vertical stress is maximum, intermediate or minimum with respect to the horizontal stresses. If the vertical stress is maximum, the hanging wall is moving downwards with respect to the foot wall and the normal faulting is observed along a deeply steeping fault. If the vertical stress is minimum, the crust is in horizontal compression and the hanging wall is moving upwards with respect to the foot wall and reverse faulting is observed along a shallow dipping fault. Finally, if the vertical stress is intermediate, the foot and hanging walls are moving horizontally and the strike slip faulting is observed along a nearly vertical fault. seismically active regions and helpful for rough assessment of stress regime (Simpson 1997; Hardebeck and Michael 2006). Stress is the key in understanding the behavior offaults and other tectonic structures such as deformation processes of the crust. Stress field studies in activezones have widely developed within the last 30 years, by means of in site measurements;faults slip data and focal mechanisms of earthquakes. Focal mechanisms of earthquakeshave long been used to probe the stress field in continental

  ti = ij n = 1 Additionally, the traction vector ti can be resolved into shear and normal components. The normal stress component scalar) acting in the direction of n, and causes either tensile (opening) or compressive (shortening) on the weakness plane as function of its sign. In engineering and material science, the convention is that positive stresses are tensional, and compressional stresses are negative. The other one is the shear stress component acting along the plane itself (parallel to the fault plane). The two components are perpendicular to each other and related by

  determined according to the orientation of the fault plane and the slip line and the sense of movement. These quadrants are plotted on the reference grid and all orientations of the grid falling in the extensional quadrants are given a counting value of 100% while those falling in the compressional quadrants are assigned 0%. This procedure is repeated for all fault-slip data. The counting values are summed up and divided by the number of faults analyzed. The grid of counting values for a single fault defines its characteristic counting net. The resulting grid of average counting values for a data subset forms the average counting net for this subset. The possible that have values of 0% and 100%, respectively.

  allows to optimize a wide variety of functions, independently or combined according to the nature of tectonic structure fault planes; maximization of shear stress magnitude on fault planes and shear joints; minimization of normal stress magnitude on extensional joints (tension veins) and maximization of normal stress magnitude on compressional joints (cleavage, styloliths). The TENSOR procedure optimizes the appropriate function by progressive rotation of the tested tensor around each of his axes, and by testing different values of R ratio. The amplitude of rotation angles and values of R ratio tested are progressively reduced until the tensor is stabilized. In fact most stress tensors were computed using an optimized composite function (F5 in TENSOR), with simultaneous minimization on fault planes and shear efficient in paleostress inversion of mixed data sets (Reference). In case of inversion of earthquake focal Mechanism data this function combines the minimization of the every fault plane. As a whole the rotational optimization progressively improves the tensor and selects one focal plane for each mechanism on the basis of the slip

Folk

  's (1968) "inclusive graphic skewness is determined by the equation:Where 5, 16, 50,[START_REF] Neev | The Pelusium megashear system across Africa and associated lineament swarms[END_REF]95 represent the size at 5, 16, 50, 84,95 percent of the sample by weight Symmetrical curves have a skewness equal to 0.00; those with a large proportion of fine material are positively skewed; those with a large proportion of coarse material are negatively skewed. A verbal classification for skewness suggested byFolk (1968) includes: +0.10 to -0.10 as nearly symmetrical; -0.10 to -0.30 as coarse-skewed; -0.30 to -1.00 as strongly coarse-skewed.4. Kurtosis is a measure of "peakedness" in a curve.Folk's (1968) formula for kurtosis is:where the phi values represent the same percentages as those for Skewness. A normal Gaussian distribution has a kurtosis of 1.00 which is a curve with the sorting in the tails equal to the sorting in the central portion. If a sample curve is better sorted in the central part than in the tails, the curve is said to be excessively peaked, or leptokurtic;

Fig. 5

 5 Fig.5 Optical arrangement for thin film diffractometry

Fig. 6

 6 Fig.6 Scheme of tsunami onshore run-up (UNESCO-IOC (2006))

  but the possibility of landslide tsunami associated with local earthquakes[START_REF] El-Sayed | Seismicity and seismic hazard in Alexandria (Egypt) and its surroundings[END_REF]) may also exist.Yalciner et al. (2014) estimated that up to 500 km3 landslide volume, with wave height ranging from 0.4 to 4 m, might have taken place offshore the Nile Delta. However, the effects of landslide tsunami are limited to the nearby coastline as shown by the recent examples of landslide tsunamis in the Mediterranean associated with the eruption of Stromboli volcanic eruption of 30 December 2002[START_REF] Tinti | The 30 December 2002 landslide-induced tsunamis in Stromboli: sequence of the events reconstructed from the eyewitness accounts[END_REF].

Figure 1 :

 1 Figure 1: Seismicity (instrumental with M> 5.5) and main tectonic framework of the east Mediterranean regions. Black boxes indicate the paleoseismic sites of Kefr Saber and El Alamein east of the Nile delta. The major historical earthquakes (blue box) of AD 365 (Mw 8 8.5), AD 1303 (Mw ~8) and AD 1870 (Mw > 7 7.5) are located along the Hellenic subduction zone according to[START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF],[START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF] andAmbraseys (2009).

  recognized major tsunamis along the eastern coast of Hokkaido (northern Japan) due to extensive coastal inundation and repeated sand sheet layers several kilometers inland; the repetition of this layer evidenced a 500-year tsunami cycle in the period between 2000 and 7000 years BP. Along the coast of South Andaman Island (India), Malik et al. (2011) studied coastal deposits in trenches and identified three historical tsunamis during the past 1000 years comparable to the 2004 Sumatra earthquake tsunami. In the Mediterranean, De Martini et al. (2012) identified two tsunamis deposits during the first millennium BC and another one in 650-770 AD and estimated 385 year average recurrence interval for strong tsunamis along the eastern coast of Sicily (Italy).

  plateau runs from the Qattara Depression southward to the piedmont plain northward with various elevations reaching ~100 m at Marsa Matrouh escarpment. The landform geomorphology of the study area is characterized by the 60-m-high northern plateau that includes ridges, sand dunes, lagoons, and rocky plains within a 20-km-wide strip along the coastline (Fig 1). The rocks correspond to a veneer of carbonate sand mostly composed of carbonate oolitic grains, entirely composed of Pleistocene limestone ridges (Frihy et al., 2010).

Figure 2 :

 2 Figure 2: Location of trenches and core sites at (a) Kefr Saber and (b) El Alamein (see also Figure 1).

  Hosseini et al., 2016) and the accessibility in order to avoid urbanization and artificial soil reworking. Suitable sites for trenching and coring are therefore located in dry lagoons (during summer season) protected from the sea by 2 to 30-m-high sand dunes. Two sites with ~200 km apart have met the selection criteria for site investigation (Figs.1 and 2): 1) Kefr Saber located at ~32-km west of Marsa-Matrouh city, and 2) El Alamein site at ~10 km northwest of El Alamein city. Five trenches were dug at Kefr Saber (Fig.2a), and 12 cores were performed at the Alamein site (Fig.2b).

Figure 3 :

 3 Figure 3: a) Kefr Saber trench size, (b) location in lagoon depression south of dune ridge, and (c) description of sedimentary layers of trench P 4 with carbon dating sampling (yellow flag); the graduated vertical ruler indicates 10 cm scale.

Figure 4 :

 4 Figure 4: a) Core 1 photography, X-ray scanning, lithology log, magnetic susceptibility, mean grain size, sediment sorting, total organic and inorganic matter and bulk mineralogy. The arrows show the high values of each measurement that may correlate with tsunami deposits.

Figure 4 :

 4 Figure 4: b) Core 9 photography, X-ray scanning, lithology log, magnetic susceptibility, mean grain size, sediment sorting, total organic and inorganic matter and bulk mineralogy.

Table 7 :

 7 Summary of different tsunami wave propagation and arrival time scenarios in the Eastern Mediterranean from historical earthquake data.

Table 8 :

 8 Summarized the possible warning tsunami message depend on historical data. xix parameters of the present day stress tensor deduced from focal mechanisms data are calculated using the Tensor program version 5.8.6 of 23 November 2016 for the six active

  sur le plateau continental du delta du Nil. Les événements sismiques historiques des années 320 et 956 se sont produits au nord de l'épicentre du tremblement de terre du 12 septembre 1955(Korrat et al., 2005). Ces tremblements de terre ont été suivis par d'autres grands événements survenus dans les 57 ans de l'événement du 19 octobre 2012 à 03: 35: 11.2, avec Cette zone est située dans la partie nord du désert occidental et à l'ouest de la zone Le Caire -Suez. Le plus grand événement dans la zone de Dahshour avec M L 5.9 est l'événement du 12 octobre 1992 qui a causé de gros dégâts principalement au Caire (voir le chapitre III pour des informations détaillées). 15 mécanismes focaux collectés dans cette zone montrent des failles normales avec des plans nodaux orientés NW-SE à E-W avec une composante décroissante

Mb 5.1 selon le Centre sismologique euro-méditerranéen (EMSC). Le séisme récent d'El Alamein s'est produit les 03 septembre 2015 (M L = 4.5) et la faille d'El Alamein a été considérée comme une continuation de la zone de faille AL Qattara-EL Alamein qui s'étend de la zone de Rosetta dans la marge continentale. Les résultats de 19 mécanismes focaux collectés dans la marge continentale égyptienne (Zone A, tendance A, B et zone adjacente montrent deux types de régimes tectoniques): Le premier groupe de mécanismes est représenté par NW Oblique (normaldextrale) failles et la seconde est représentée par des failles EW à ENE (reverse -latéral gauche) L 'inversion de contrainte de notre étude de la zone marginale égyptienne est classée en deux tendances principales A, B. L' inversion de contrainte de la tendance A représente les contraintes dans la tendance de Rosetta et s'est poursuivie avec la distribution des contraintes d'Alexandrie à la marge d'El Alamein (Qattara -EL Alamein Ridge).

L'inversion de contrainte de la tendance B comprenait 8 solutions de mécanismes focaux, ce qui représente les contraintes parallèles à la tendance de Rosetta jusqu'à la région de Mars Matrouh L'indice du régime de contrainte R 'de la tendance B est de 2.12 et montre une compression pure (TF) avec Tensor Quality B.

Les tendances de Tamash et Baltim à l'est de la marge continentale sont caractérisées par de faibles données de sismicité. L'orientation du stress de l'étude en petits groupes de

[START_REF] Tingay | Present-day stress-field rotations associated with evaporites in the offshore Nile Delta[END_REF]

utilisant 11 puits sur le front du delta du Nil indique un N-S dominant à NE-SW Sh. orientation maximale et une orientation secondaire E-W à NW-SE. Nos résultats de stress ne concordent pas avec les données de trou de fracture de

[START_REF] Tingay | Present-day stress-field rotations associated with evaporites in the offshore Nile Delta[END_REF]

dans le cas de la tendance de Rosetta, car les données de forage ont une faible profondeur plutôt que la profondeur des séismes.

xxvii La deuxième zone active dans le nord de l'Egypte est la zone de Dahshour (B).

  . L'inversion de contrainte calculée dans la zone de Dahshour résulte de 19 mécanismes focaux dans cette zone, produisant un régime de stress étendu caractérisé par des failles de tendance NE-SW avec N25° E Shmin. L'indice de contrainte R 'est de 0.69, ce qui est compatible avec le défaut normal et la composante de décrochement; la qualité du Tenseur est B. Ces résultats concordent avec l'inversion de contrainte calculée par Hussein et al. (2013). SW avec N44E Sh-min. L'indice du régime de contrainte est R '= 0.64. Cette valeur est cohérente avec un régime normal de défaut et d'extension, où l'optimisation rotationnelle des défauts réels montre la qualité du Tenseur A.La cinquième zone active dans le nord de l'Egypte est le sud du golfe de Suez (E). la Méditerranée orientale et le nord de l'Egypte pour avoir une image complète de la distribution actuelle des contraintes. La principale conclusion des résultats du stress montre que l'ensemble de l'Égypte septentrionale est soumise à un régime de stress d'extension, à l'exception de la marge continentale égyptienne qui montre des tendances à la compression. Ce régime de stress fonctionne actuellement dans la plupart des régions du nord de l'Egypte comme des failles normales et des glissements avec des tendances Shmin N-NNE. Egypte orientale et septentrionale, quatre zones actives sont identifiées comme étant à l'origine d'éventuels tsunamis. L'arc hellénique oriental, l'arc hellénique occidental, l'arc cyprien, la marge continentale égyptienne. Les arcs helléniques de l'Est et de l'Ouest sont considérés comme les zones tectoniques les plus actives à longue distance et une source

	Les deux plus grands tremblements de terre sont enregistrés dans cette zone, à savoir les majeure de tsunamis qui peuvent frapper les côtes égyptiennes et les régions
	tremblements de terre de l'île de Shadwan le 31 mars 1969 (ML = 6.1); et le 28 juin 1972 méditerranéennes adjacentes. Le catalogue historique de sismicité rapporte trois événements
	(ML = 5.0). Les 29 mécanismes de failles normales du mécanisme focal collecté avec les sismiques significatifs de la zone de subduction hellénique avec des tsunamis majeurs qui
	tendances NW-SE. Les inversions du tenseur des contraintes ont été appliquées à 28 Chapitre IV Paléontunami: Ce chapitre décrit les effets de grands tsunamis ont affecté la côte méditerranéenne de l'Egypte:
	mécanismes focaux du sud du golfe de Suez. L'inversion des mécanismes focaux des historiques comme le 21 juillet 365, le 8 août 1303, le 24 juin 1870 sur la côte égyptienne 1) Le tremblement de terre et l'événement tsunamigène du 21 juillet 365 (Mw 8,3 -
	tremblements de terre dans cette zone donne lieu à un régime de stress important caractérisé septentrionale et les côtes méditerranéennes adjacentes. Les informations sur le tsunami ont 8,5; Stiros et Drakos, 2006; Shaw et al., 2008),
	2) Le tremblement de terre et l'événement tsunamigène du 8 août 1303 (Mw 7,8 -
	8,0) (Abu El Fida, 1329)

La troisième zone active dans le nord de l'Egypte est la zone de Suez du Caire

(C)

située à l'ouest du golfe de Suez en suivant la route du Caire Suez et au nord du désert oriental. Les deux grands événements sismiques sont survenus les 29 septembre 1984, M L = 4.5 et le 29 avril 1974 de M L = 4.6. La plupart des mécanismes enregistrés montrent principalement des failles normales pures et une source oblique de la composante normale avec les tendances E-W et NWN-SES et NW-SE en accord avec la direction générale de la direction des failles exposées. Les inversions du tenseur des contraintes sont appliquées à 12 événements de mécanismes focaux pour la zone Cairo-Suez. L'inversion des mécanismes focaux des tremblements de terre dans cette zone produit un régime de contrainte étendu caractérisé par des failles de tendance NE-SW avec N18.7°E Sh-min. L'indice de contrainte est R'= 0.69 représentant un défaut normal avec une composante de défauts de frappe (transtensive) de qualité Tenseur A. L'optimisation rotationnelle des défauts réels montre un tenseur de contrainte de qualité A. La quatrième zone active située dans le nord de l'Egypte est au nord de la zone du golfe de Suez (D) et est considérée comme un rift continental néogène qui a évolué comme un bras de la triple jonction du Sinaï avec le golfe d'Aqaba et la mer Rouge. . Dagett et al. (1986) l'ont considérée comme une zone active malgré l'absence de grands séismes dans cette zone. Les 15 solutions focales collectées sont caractérisées par des mécanismes de failles normales. Les avions nodaux ont des directions proches de NW-SE à NNW-SSE. Le reste des solutions présente des mouvements obliques ou purs de glissement. 14 événements de mécanismes focaux pour le nord du golfe de Suez sont appliqués aux inversions du tenseur des contraintes. L'inversion des mécanismes focaux des tremblements de terre dans xxviii cette zone donne un régime de stress étendu pur caractérisé par des failles de tendance NEpar des failles de tendance NE-SW avec N27.8 ° E Sh-min. L'indice du régime de contrainte est R '= 0.51 et la qualité du Tenseur A. La sixième zone active dans le nord de l'Egypte est la zone du golfe d'Aqaba (souszones F, G) considérée comme une région source d'activité intense qui constitue la principale limite de la plaque tectonique entre l'Afrique (Sinaï) et l'Arabie. Le plus grand séisme enregistré (Mw = 7.2) est survenu le 22 novembre 1995. Les 36 solutions focales présentent des failles normales avec un décrochement latéral gauche ou un décrochement avec une composante normale mineure, tandis que certains événements reflètent un mécanisme de failles normal. . La plupart des événements montrent des axes T approximativement dans la direction NNE à N-S et NW. Les inversions du tenseur des contraintes ont été appliquées à 7 événements de mécanismes focaux pour la zone F de la zone du golfe d'Aqaba. Cette zone est située au nord de 29° de latitude. L'inversion des mécanismes focaux dans cette zone montre des failles normales, où l'indice du régime de contrainte est R '= 0.89, N72.3ºE pour Sh-min et Tensor qualité A. La sous-zone G est située au sud de 29 ° de latitude, où le stress les inversions tensorielles sont appliquées à 27 mécanismes focaux. L'indice du régime de contrainte est R'= 0.98, avec N 59.3° E Shmin et Tensor Qualité A. L'inversion des mécanismes focaux des tremblements de terre dans cette zone donne un défaut normal avec la composante décroissante.

Pour compléter l'image de la déformation et de la direction des contraintes, j'ai également compilé dans le chapitre III: a) les vecteurs de vitesse GPS pour estimer le taux de déformation

[START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF]

; b) l'inversion de contrainte calculée dans cette étude en utilisant la version 5.8.6 du programme Tensor du 23/11/2016

(Delvaux et al., 2010)

; c) les contraintes calculées par les études sur les forages de puits de pétrole

[START_REF] Tingay | Present-day stress-field rotations associated with evaporites in the offshore Nile Delta[END_REF]

; d) xxix les contraintes de la carte mondiale des contraintes (http://www.world-stress-map.org/) dans la région de été conservées dans les documents historiques et les catalogues récents comme Ambrasey (2009) et

Guidoboni (2009)

. À l'heure actuelle, les données du paléosunami n'existent que pour un nombre limité de régions sismiquement actives du monde. L'arc hellénique et la zone de subduction connexe sont considérés comme la source dangereuse des tsunamis qui ont pu affecter la côte nord égyptienne dans le passé et générer des tsunamis dans le futur.

On supposait que la ville de Thonis -Heracleion avait sombré à cause d'un tsunami survenu dans le passé (??). Cette ville a été fondée en 331 avant J.-C et était un port d'entrée en Egypte et le Nil pour tous les navires venant de la région grecque. Un fort tremblement de terre s'est produit le 21 juillet 365 dans le segment ouest de l'arc hellénique, avec des signes de soulèvement et de basculement jusqu'à 9 m dans l'île de Crète

[START_REF] Stiros | The 8.5+ magnitude, AD365 earthquake in Crete: Coastal uplift, topography changes, archaeological and historical signature[END_REF]

. Cet événement a provoqué un tsunami qui a dévasté la ville d'Alexandrie en Égypte et a envoyé un mur d'eau à travers la Méditerranée vers la côte nord-africaine et toute la Méditerranée orientale, y compris le sud de l'Italie

(Ambraseys, 2009)

. Les navires dans le port à Alexandrie ont été renversés pendant que l'eau près de la côte a reculé soudainement. Les rapports indiquent que beaucoup de gens se sont précipités pour piller les navires malheureux (cela a été mentionné par Ammianus Marcellinus qui a vécu pendant ce temps à Ambrayses (2009) .La vague de tsunami s'est ensuite précipitée dedans et a porté les navires au-dessus des murs de mer. A Alexandrie, environ 5000 personnes ont perdu la vie et 50 000 maisons ont été détruites Le tremblement de terre du 8 août 1303 a été considéré comme le deuxième plus grand séisme et tsunami de la côte égyptienne. les effets effrayants de ce raz de marée sismique exceptionnel (tsunami) qui a frappé de nombreuses localités du bassin méditerranéen (Ambrayses 2009)

Guidoboni et Comastri (2005)

ont suggéré que cette vague de mer étendue a été causée par un tremblement de terre et son épicentre entre les îles de Crète et Rhodes. xxx A partir de l'étude des événements sismotectoniques et paléotsunami d'origine sismique en 3) Tremblement de terre et tsunamigène du 24 juin 1870 (ML 7 -7.5) (Ben Menahem, 1979). Les trois événements ont causé de grands dégâts sur la côte égyptienne et ont particulièrement affecté la ville d'Alexandrie avec des inondations côtières et des inondations. l'eau dans le nouveau port d'Alexandrie a éclaboussé sur le quai (Ambraseys

  Le premier est la présence de gros rochers observés le long de la côte dans le nord de l'Egypte dans des localités telles que Ras El Hekma -Ras ELAlam Rum -Mersa Matrouh -les tranchées ont été décrites en fonction de leur longueur, de leur couleur, de leur texture (granulométrie, tri), des structures sédimentaires (naturelles ou dues à des carottages), du type de contact sédimentaire (acéré ou dégradé). Les carottes et les tranchées ont ensuite été photographiées à l'aide d'un reflex numérique à reflex numérique (Appareil photo reflex numérique à objectif unique) en sections de 25 cm de long, avec un chevauchement d'au moins 2 cm. Ces images ont été assemblées pour reconstruire une seule image pour chaque section de base. La deuxième couche est d'environ 13 cm d'épaisseur à 50 cm de profondeur, caractérisée par des dépôts sableux blancs intercalés de sable brun grossier avec stratification horizontale, de mauvais sédiments de triage, riches en matière organique totale et un fort pic de susceptibilité magnétique. C) La troisième couche ~ 18 cm d'épaisseur à 89 cm de profondeur est faite de sable jaune mélangé avec des intercalations de sable blanc, avec des laminations au fond des dépôts, directions gastropodes verticales et horizontales reflètent le courant de haute vague, fragments de coquilles brisées, riches dans la matière organique totale et la pyrite montrant un pic élevé de susceptibilité magnétique. D) La quatrième couche de tsunami est à 151 cm de profondeur avec une épaisseur de 19 cm. Il est caractérisé par du sable jaune pâle, moyen à fin, avec des fragments de coquilles brisés et un tri extrêmement pauvre, avec un haut pic de susceptibilité magnétique, et un haut pic de matière organique > 5.5% en poids et une quantité élevée de gypse.

	Est Mersa Matrouh (Kefr Saber) avec une riche teneur en fossiles de Dendropoma. La
	datation calibrée de l'échantillon de Dendropome à Kefr Saber est 940-1446 AD qui peut
	être corrélée avec une vague forte et élevée (> 5m) à la côte de Kefr Sabre probablement La susceptibilité magnétique a été mesurée avec des intervalles de 3 cm le long des
	durant ce tsunami du 8 août 1303. Ce résultat coïncide avec celui de Shah-Hosseini et al., carottes en utilisant un système Bartington MS-2. Des échantillons d'une dimension de 2 cm
	(2016) le long du même littoral. de long ont été collectés tous les 15 cm pour la minéralogie en vrac, la taille des grains,
	l'analyse organique et inorganique totale qui a été réalisée au laboratoire d'un institut central
	de recherche métallurgique (CMRDI) à Helwan.

Trois travaux de terrain ont été réalisés en utilisant des tranchées et des carottages sur les sites de Kefr Saber et El Alamein en juin 2014, août 2015 et octobre 2015 dans la côte nord de l'Egypte. Le but de ce travail de terrain était de 1) étudier la géologie et la géomorphologie de la côte nord de l'Egypte. 2) Etudier l'enchaînement successif de la stratigraphie dans les sites sélectionnés d'EL Alamein et de Kefr Sabre et 3) caractériser l'âge des couches possibles de tsunami en fonction de la chronologie des datations au carbone et des signatures des tsunamis.

xxxi Pour la sélection du site paléotsunami,, les critères géomorphologiques et topographiques ont été pris en compte ainsi que l'accessibilité afin d'éviter l'urbanisation et le remodelage artificiel des sols. Les critères géomorphologiques sont:

Les deuxièmes critères géomorphologiques sont la présence de dunes côtières le long de la côte égyptienne. Elles sont composées de sables carbonatés blancs et blancs, délavés, provenant de la dégradation des dorsales côtières oolithiques de 2 à 20 mètres de hauteur.

Derrière ces dunes de sable, les troisièmes critères de géomorphologie sont les lagunes ou marais salés que l'on trouve entre des crêtes disséquées avec parfois une élévation inférieure au niveau de la mer à l'ouest de Marsa Matrouh.

Cinq tranchées ont été réalisées à Kefr Saber ~ 32 km à l'ouest de Marsa-Matruh. 12 sondages carottés ont été réalisées dans le deuxième site sélectionné d'El Alamein. Les sondages carottés ont été réalisés en utilisant un instrument de forage cobra. La taille des tranchées était ~ 2 x 1 mètre avec ~ 1.5-m-profondeur et la profondeur maximale des noyaux est ~ 2.6 m. Les tranchées sont enregistrées et photographiées avec une description détaillée et un échantillonnage pendant les travaux sur le terrain à Kefr Saber. Alors que les carottes réalisées sur le site d'ElAlamein étaient divisées en deux dans le laboratoire NRIAG avec Fisher Wire. Un pour les archives et l'autre pour l'analyse de la sédimentation et du contenu. Le noyau étudié comprend la collecte d'échantillons pour la datation, la photographie, les descriptions stratigraphiques détaillées, le balayage des rayons X, l'analyse géochimique et la susceptibilité magnétique. L'objectif principal est d'identifier les dépôts de Paleotsunami dans les grumes stratigraphiques en fonction des signatures des tsunamis. Des radiographies radiographiques ont été effectuées sur des carottes en utilisant un laboratoire de radiographie médicale avant d'être ouvertes pour identifier les détails des sédiments et des microfossiles. Des rayons X très intensifs ont été utilisés pour pénétrer dans les sédiments afin de montrer les détails dans les sédiments. Trois radiographies de 40 cm de long ont été prises pour chaque noyau de 1 m de long avec un chevauchement d'au moins 5 cm. xxxii Les carottes et La datation au radiocarbone des échantillons a été réalisée dans trois laboratoires (laboratoire de Poznan -Pologne, CIRAM à Bordeaux, France et Beta Analytical Laboratory, USA) pour assurer des résultats cohérents et de haute qualité. Les échantillons prélevés étaient constitués de charbon de bois, d'os, de gastéropodes, de coquilles et de matières organiques. Les résultats de datation au radiocarbone du charbon et de la matière organique ont été étalonnés en utilisant une courbe d'étalonnage récente (Reimer et al., 2013) et le logiciel Oxcal pour la fonction de densité de probabilité de chaque âge d'échantillon avec incertitude 2 (Bronk-Ramsay, 2009); de plus, les gastéropodes et les coquilles ont été corrigés par rapport aux effets du réservoir. Deux sections composites ont été construites pour résumer les stratigraphes et les couches de tsunami reconnues sur le site de Kefr Sabre et EL Alamein avec la chronologie et la simulation des événements historiques paléotsunamis 1600 avant J.-C, 21 juillet 365, 8 août 1303 et un tsunami plus récent le 24 juin 1870 Les troncs stratigraphiques des tranchées de Kefr Saber montrent principalement une couche de sable et de gravier mélangés à des tsunamis, et des coquilles brisées à une profondeur d'environ 35 cm et une épaisseur de 20 cm comparable aux dépôts de tsunami du 21 juillet 365. Les carottes d' El Alamein montrent quatre couches principales caractérisées par un sable fin et grossier mélangé à des fragments de coquilles brisées qui indiquent la présence de dépôts sédimentaires à haute énergie dans l'environnement du lagon côtier. Les diagraphies stratigraphiques dans les carottes montrent quatre couches principales de tsunami; A) La première couche a ~ 7.5 cm d'épaisseur à ~ 19 cm de profondeur et est faite de dépôts de sable blanc mal triés avec des gastéropodes brisés et des fossiles de lamellibranches. La valeur élevée de la matière organique et le pic élevé de xxxiii susceptibilité magnétique reflètent une teneur riche en carbonates et en quartz. B) Le chapitre V, je prends comme exemple la récente modélisation significative des tsunamis telle que le tsunami massif généré par le tremblement de terre majeur de Tohoku de Mw 9.0 le 11 mars 2011, avec un hauteur maximale des vagues atteignant 19.5 m dans la plaine de Sendai (Mori et al., 2011). Dans mon travail, deux scénarios simples sont construits en utilisant la mise à jour du logiciel Mirone version 2.7.0 modifiée le 22 octobre 2016 (Luis, 2007) en utilisant les données des dépôts de tsunami du 21 juillet 365 et du 8 août 1303. Les deux pires scénarios simples avec des sources de tsunami actives à haute possibilité ont été construits en créant la vague initiale de ruptures de failles calculées pour les arcs helléniques occidentaux et helléniques orientaux. La hauteur des vagues et les temps de parcours ont été calculés dans ces deux scénarios en fonction de l'historique des localisations sources, par exemple le 21 juillet 365 (Stiros, 2010) et le 8 août 1303

  en une hauteur de vague de ± 5 m dans le cas du scénario de l'est et de ± 1.5 m dans le scénario de l'ouest de l'arc hellénique Dans le scénario hellénique oriental, la propagation d'onde calculée est effectuée toutes les 0, 33, 50, 66, 80 minutes. Après 30 minutes, la vague initiale arrive et après 50 minutes, la vague maximale atteint 7 à 10 mètres dans les sites de Kefr Saber et El Alamein.

	Dans le scénario Hellénique de l'Ouest, la propagation de l'onde de tsunami est calculée à 0,
	33, 66, 100, 150 minutes. La hauteur des vagues atteint 4-10 m à l'heure d'arrivée 33
	minutes sur la côte libyenne. La vague arrive à la côte égyptienne après 66 minutes avec une
	hauteur de vague légèrement inférieure à celle de la côte libyenne. La hauteur de la vague
	arrive à la côte égyptienne avec 0.8 1.7 m à Kefr Saber et avec une hauteur de vague de
	0,4 à 0,8 m à El Alamein après 100 minutes. Les vagues du tsunami couvrent toute la côte
	égyptienne après 150 minutes du scénario de l'ouest de l'arc hellénique.

). Les données de bathymétrie utilisées sont la grille de 30 secondes d'arc à partir des données GEBCO disponibles en ligne, et ceci en l'absence de la résolution plus détaillée (1 seconde d'arc ou moins) des données de bathymétrie côtière dans ma zone d'étude. Les incertitudes sont calculées pour la géométrie de la faille (longueur, largeur et glissement) utilisée dans les arcs helléniques est et ouest en comparaison avec les études précédentes. De plus, les incertitudes sont calculées en hauteur des vagues (m) selon les 5 xxxiv scénarios testés résultant

  Mes recommandations dans le chapitre VI sont 1) l'heure d'arrivée minimum pour que les vagues du tsunami arrivent à la côte égyptienne étant 30 minutes dans le cas de l'arc hellénique oriental et 66 minutes dans l'arc hellénique occidental cela laisse assez de temps pour prendre mesures de protection et d'envoyer des alarmes à la défense civile et la côte égyptienne et sauver des vies. J'ai construit un tableau pour suggérer des messages d'alerte possibles en fonction des données historiques, des données de simulation en fonction des grandeurs de séismes multisystémiques à fournir aux décideurs en cas de risque de tsunami.Les messages d'alerte nécessitent une coopération étroite avec les centres d'études sur les tsunamis turcs et grecs et sont classés en fonction de l'échelle locale, régionale et du bassin.

hauteur des vagues à Alexandrie dans le cas du scénario de l'ouest de l'Hellénisme. Chapitre (VI), ce chapitre est le dernier concluant qui montre les résultats finaux obtenus par la sismicité, les mécanismes focaux, l'inversion de contrainte calculée, les données géodésiques pour identifier la déformation actuelle et le régime tectonique de stress principal dans le nord de l'Egypte et sud-est méditerranéen. Le résultat principal est que toute l'Egypte du nord est considérée comme faisant partie du régime d'extension sauf la marge continentale égyptienne. Sur la base de l'étude du paléotsunami, les principales sources sismiques tsunamigènes avec des potentiels Mw> 8 dans la région de la Méditerranée orientale (arc hellénique oriental et occidental) sont prises en compte. Ces arcs ont été considérés comme la zone de subduction la plus dangereuse et les segments sources des futurs tsunamis possibles dans cette région pour le nord de l'Egypte. Les résultats obtenus lors du creusement à Kefr Saber sont corrélés au 21 juillet 365 à Kefr Saber, tandis que les quatre couches de tsunami dans les carottes du site d'El Alamein sont corrélées avec les événements historiques du tsunami de 1600 avant J.-C , 21 juillet 365, 8 août 1303, 24 Juin 1870. Ce chapitre se termine par la perspective de la sismotectonique de l'Égypte, y xxxv compris l'étude de la faille quaternaire active d'El Alamein et d'autres recherches sur les dépôts paléotsunamis.

Table 1 : Diffraction standard main peak identify minerals according to (ICDD) Minerals Principal diffraction peak (Å)

 1

	Gypsum (CaSo4.2H2O	7.56
	Quartz	3.34
	Calcite	2.92
	Dolomite (CaMg(Co3)2	2.89
	Feldspar (Albite)	3.1875
	Feldspar (Orthoclase )	3.3193
	Aragonite	3.3985
	Halite	2.81
	Goethite	4.19
	Pyrite (FeS)	2.7090
	Illite	10
	Montmorillonite	15

Table 2 :

 2 The earthquakes parameters and stress axes of the significant earthquakes in northern Egypt.

	No .	Date	Time	Location (º) Lat. Long.	Depth (Km)	Mag. (Mb)	P axis	T axis	References
	a	12/09/1955 06:09:24 32.20 29.60 33	6.7	346 06 251	32 Hussein (1989)
	b	31/03/1969 07:15:54 27.61 33.91 6.2	6.1	019 82 203	08 Hussein (1989)
	c	12/10/1992 13:09:55 29.76 31.14 22	5.8	175 61 293	49 CMT
	d	22/11/1995 04:15:11 28.76 34.66 9.0	7.3	159 31 062	12 CMT
	e	28/05/1998 18:33:28 31.45 27.64 10	5.5	67	43 243	47 Huessein (2008)

Table 3

 3 The Egyptian continental margin was classified into two types according to the mechanisms revealed from the earthquake data. The first group of mechanisms is represented by NW Oblique (normal dextral) faults considered as Trend A and the second group of mechanisms is compressive represented by E-W to ENE (reverse left-lateral) faults considered as Trend B.

) using Stress

Tensor inversion software (version 5.8.5).

3.6. a. The Egyptian continental margin (Zone A, trend A and B)

Table 3 :

 3 Parameters of the present day stress tensor deduced from focal mechanisms in this study.

										º
	Seismic zone							R	º		n/nt		Shmax.º	Shminº
		Az.	Pl.	Az.	Pl.	Az	Pl.			max
	Continental
	margin Zone A	74	168	13	313	09	45	0.79	18.4	33.4	14/18	0.67	136	39.2
	Trend A
	Continental
	margin Zone A	10	67	04	336	79	255	0.12	6.1	20.8	8/16	2.12	79	165
	Trend B
	Dahshour Zone B	67	125	23	292	05	24	0.83	18.3	22.4	24/34	0.69	114	N25E
	Cairo-Suez Zone C	63	286	27	108	01	18	0.79	10.7	20.8	15/36	0.69	108	N18.7E
	North Gulf of Suez Zone D	61	130	29	317	03	225	0.64	12	24.9	15/28	0.64	134	44
	South Gulf of Suez Zone E	77	97	11	311	07	219	0.68	11	23.8	24/56	0.51	128	27.8
	Gulf of Aqaba sub zone F	45	170	44	338	06	74	0.9	13.5	26.8	10/14	0.89	164	72.3
	Gulf of Aqaba sub zone G	09	212	09	336	14	68	0.89	11.4	38.6	24/54	0.98	161	59.3

  The main differences between[START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF] Saleh and[START_REF] Saleh | New constraints on the Nubia-Sinai-Dead Sea fault crustal motion[END_REF] the last estimated that the GPS results relative motion in Nubia was 6.5±1 mm/yr higher than estimated by[START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF] which is 5 mm/yr. Also, Saleh and Becker 2015 estimated the motion of Sinai plate with 8.2±0.8 mm/year as separate motion from Nubia

	plate.
	Recently, Pietrantonio et al., 2016 suggested that the Sinai moved in a
	4 ± 08 mm/yr
	northward and 0.4±0.8mm/yr eastward relative to the stable Nubia plate. Saleh and Becker,
	(2015) used 16 permanent GPS stations in combination with 47 non-permanent stations
	covering Egypt for the period 2006 2012. Their GPS results show relative motion between

Previous studies indicate the northward motion of northern Nubia with respect to Eurasia by about 5mm/yr

[START_REF] Mcclusky | Global Positioning System constraints on plate kinematics and dynamics in the eastern[END_REF][START_REF] Reilinger | GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions[END_REF]

.

[START_REF] Mahmoud | GPS evidence for northward motion of the Sinai block: Implications for E. Mediterranean tectonics[END_REF]

defined Sinai as a separate subsandwiched African plates. Mohamoud et al.,(2005) suggested that Sinai sub-plate bounded by the Gulf of Aqaba Dead Sea fault, Gulf of Suez and Cyprus Arc with a motion of 1.Nubia and Eurasia of about 6.5±1 mm/yr which may increase toward the Hellenic trench, 8.2±0.8 mm/yr in Sinai Peninsula, 14.2±1.4 mm/yr in the north on the of the Arabian plate, and 22.3±0.7mm/yr in eastern and central Anatolia.

Table 2 in

 2 Appendix E). The second is a bone sample from a depth of 50 cm and has a calibrated age of 403-603 AD. The first sample is transported from deep sediments as this sample is located in first stratigraphic tsunami layer. This sample is transported due to high current waves because of tsunami waves. The second sample is between two tsunamis in stratigraphic succession 1 and 2. This sample reflects the probable tsunami of 8 August 1303 above and 21 July 365 below.

Table 1

 1

in Appendix E) in the Ras ELHekma and Kefr Saber for dating. Our dating result of Dendropoma in Ras el Hekma has a calibrated date of 6812-7597 BC. This means that these boulders may have been transported as a result of a strong storm or tsunami during the old ages (6812-7597 BC). The calibrated date of Dendrompa at Kefr Saber was a 940-1446 AD. This Dendropoma sample date coincides with the 8 August 1303 tsunami and these results agree with

Shah-Hosseini et al., (2016)

.

Table 5 :

 5 Fault geometry and parameters (see Fig.67) in the east Hellenic arc used for our modelling and scenario modified afterPagnoni et al., 2015.

	Fault parameters	Values	Uncertainty Measured
				value
	Length	124 km	±65	116±65
	Width	47 km	±9	37±9
	Slip	8 m	±1.5	7±1.5
	Depth (at the bottom of fault) 57 km
	Rigidity	3×10 11 dyne/cm 2
	Seismic moment (Mo)	1.4 × 10 28 dyne.cm
	Mw	8.0 dyne.cm
	Strike	54°
	Dip	55°
	Rake	90°

Table 7 :

 7 Summary of different tsunami wave propagation and arrival time scenarios in the

Table 8 :

 8 Summary of the possible warning tsunami message, EHA and WHA are the most dangerous tsunami sources.

					Tsunami Message Type
	Depth Location	Mw	Tsunami				Possible	Compared	Comments in the Egyptian coast
				Potential				Tsunami	with
					Local	Regional	Basin Wide	sources	historical events
								Off shore of Nile
				Potential				Delta (possible
			7 7.5	Destructive	Watch	Advisory	Information	simulated	None	of 2.3 m wave height at Ras at Tin
				local				volume 41 km3		37	arrival time of intail wave of
				tsunami				simulated land		4.0 at Rasheed Yalciner et al. (2014)
								slide)
								Cyprus Arc	11 May 1222 0.6 m wave height of the initial arrival
				Potential						time 66 minutes Hassan (2013)
	< 100 Km	Under the Sea	7.5-8.0	Destructive for regional Tsunami	Watch	Watch	Advisory	margin EHA, WHA, Cyprus, Egyptian continental	24 June 1870 Only historical information of wave at the Alexandria harbour
				Potential for					8 August	7-10 m wave height of arrival time wave
				a very				EHA	1303	33 minutes intial arrive at Egyptian coast
			>8	Destructive	Watch	Watch	Watch			(This study)
				Regional					21 July 365	1.7 m wave height of arrival time wave of
				Tsunami				WHA		66 minutes at the Egyptian coast (This
										study )
		Inland	>7.0	No potential	Information Information Information	-
				tsunami

Table 1 :

 1 The earthquakes events in Egyptian continental margin area Magnitude M L

	Serial	Date	Origin Time	Longitude Latitude Depth	Magnitude
	no.		(GMT)
	1	19510130	23:07:24	32.4	33.4	0	5.1
	2	19550912	6:09:24	29.8	32.9	33	6.7
	3	19870429	04:37.6	30.5	31.7	33	4.6
	4	19870409	00:04.6	28.97	32.39	10	4.6
	5	19870102	10:14:46	30.48	32.22	24.1	3.9
	6	19880609	2:18:24	27.9	32.23	10	4.8
	7	19871214	21:50:59	30.72	31.69	10	3.9
	8	19920522	23:10:44	30.18	32.01	8	4.1
	9	19921105	18:41:49	29.69	30.97	16	4.6
	10	19950908	12:13:22	29.7	32.23	13	4
	11	19960221	4:59:57	29.03	31.37	15	5.3
	12	19980528	18:33:28	27.64	31.45	22	5.5
	13	19991011	20:39:34	28.65	31.54	12.1	4.9
	14	20001216	142708.04	33.56	33.169	37.3	3.3
	15	20000601	164438	29.99	32.58	6	2.8
	16	20010612	12:43:26	29.62	31.12	0	4.1
	17	20040325	24835	30.54	31.74	24.7	3.4
	18	20121019	3:35:12	30.98	32.58	18	5.1
	19	20130117	21:17:40	30.6	31.98	10	4.9

Table 2 :

 2 The focal mechanisms parameters Egyptian continental margin area

			Plane 1			Plane 2		P-axis	Taxis
	Serial no.	Strike Dip Rake	strike	Dip	Rake	Tr.	Pl.	Tr.	Pl.	References
	1	295	64	-116	162	34	-24	168	60	42	17	Costantinescu et al. (1966)
	2	118	69	161	215	68	22	342	2	78	28	Costantinescu et al. (1966)
	3	326	40	-7	62	84.00	-5	303.8	8	212	0.7	CMT Harvard solution
												personal
	4	112	70	157	210.26 68.46 21.57 120.3 21.54	22	22	communication
												with Hussein
	5	248	80	-170	156	80	-10.00	112	14	22	0	CMT Harvard solution

Table 3 :

 3 The earthquakes events in Dahshour area M L

	6		54	40	149	58	136	209	3	115	57	Korrat et al., 2005
	7		40	-4	291	87.00	-130	167	35	52	30	CMT Harvard solution
	8		40	-7	62	85.00	-130	297	36	182	29	CMT Harvard solution
	9		48	-40	96	61.00	-130	315	54	214	9	Badawy (2001)
	10		29	-88	310	61.00	-91	217	73	41	16	Abu Elenean et al. (2004)
	11		30	-104	328	61.00	-82	257	73	52	16	CMT Harvard solution
												Personal
	12		43	87	333	43.07	87	67.2	42.93	243	47	communication
												with Hesham
	13		32	-28	259	75.00	-119	136	51	11	25	CMT Harvard solution
	14	93	73	-6	184.00	85	-163	50	16	318	8	MED-RCMT
	15	3	54	-41	120.00	58	-137	333	52	241	2	ENSN
	16		50	-107	309	43.00	-71	311	77	155	4	ENSN
	17		48	-66	101.00	47	-114	297	72	28	0.4	ENSN
	18		58	164	142.4	58	164	52.4	15.01 148.00 20	EMSC
	19	56	56	164	155.1	76.79 35.06	65.1	13.21 326.00 34	EMSC
		Serial no.		Date	Origin Time	longitude	latitude	Depth Magnitude
				(Y/M/D)		(GMT)
				19921012	13:09:59	30.63		29.74	22		5.9
				19921022	17:38:58	31.108	29.621	10		4
				19921104	16:29:39	31.133	29.716	19.6		3.5
				19921105	18:41:51	31.133	29.682	16		4.2
				19921105	18:46:05	31.101	29.661	20.9		3.6
				19921105	19:16:47	31.133	29.671	20.74		3.9
				19921106		2:42:03	31.133	29.7	18		3.7
				19921107		1:35:03	31.133	29.666	21		3.5
				19921110	11:17:19	31.133	29.656	17.8		4
		10		19930310	19:26:52	31.124	29.726	18.16		3.8
		11		19930504	20:56:51	31.123	29.68	21		3.7
		12		19930513		8:38:26	31.086	29.687	21.7		3.7
		13		19930613		6:16:09	31.116	29.671	17.6		3.9
		14		20010612	12:43:26	31.12		29.62	31.12		4.1
		15		20050731	16:14:37	31.12		29.67	22.7		4.2
		16		20080621	17:59:47	30.6		29.8	6.2		4
		17		20080602	17:59:46	30.66		29.73	6.67		4
		18		20120216		2:15:00	30.68		29.73	4.11		3.6
		19		20140728		8:09:00	30.6		29.77	4.33		3.5

Table 4 :

 4 The focal mechanisms parameters of Dahshour area M L

			Plane 1			Plane 2		P-axis	T-axis
	Serial	strike	dip	rake	strike	Dip	Rake	Tr.	Pl	Tr.	Pl.	References
	no.
	1	284.2	65.96	-117.7	284.2	65.96	-117.7	155 59	34	16	NEIC
	2	278.65	66.74	-107.81	137.78	28.88	-107.81 159 64	22	20	AbouElenean
												(1997)
	3	312.26	54.48	-59.38	86.72	45.54	-125.52 281 65	21	5	AbouElenean
												(1997)
	4	269.55	54.33	-120.79	135.17	45.74	-54.5	120 22	25	12	AbouElenean
												(1997)
	5	256.66	81.36	-150.22	161.74	60.59	-9.93	123 27	26	14	AbouElenean
												(1997)
	6	259.38	81.55	-145.54	163.62	55.97	-10.22	127 30	27	17	AbouElenean
												(1997)
	7	296.15	61.23	-65.99	73.38	36.80	-126.54 249 65	9	13	AbouElenean
												(1997)
	8	243.19	74.03	-121.46	128.97	34.91	-28.74	117 51 357	23	AbouElenean
												(1997)
	9	263.2	78.73	-138.05	163.24	49.04	-15	132 37	27	19	AbouElenean
												(1997)
	10	113.3	58.74	-79.88	274.32	32.70	-106.14	50	74 196	13	AbouElenean
												(1997)
	11	266.52	78.46	-154.67	171.11	65.22	-12.73	131 26	37	9	AbouElenean
												(1997)
	12	132.43	65.65	-64.73	263.57	34.53	-133.32	81	61 204	17	AbouElenean
												(1997)
	13	135.09	62.58	-50.41	254.2	46.84	-140.85	95	54 198	9	AbouElenean
												(1997)
	14	60.65	53.14	-96.61	251.59	37.37	-81.27	311 77 155	4	ENSN
	15	117	21	-117	326	72	-80	250 62	48	26 Emad Mohamed
												2010
	16	303.12	80.47	-23.13	37.16	67.21	-169.11 258 23 352	9	Abdelazim et
												al., (2016)
	17	48	52	-133	285	55	-48	255 57 347	1	Emad Mohamed
												(2010)
	18	47	74	-160	311	71.00	-17	269 26 178	2	Badreldin,
												(2016)
	19	233	70	-165	233	70.00	-165	95	24 186	4	Badreldin,
												(2016)

Table 5 :

 5 The earthquakes events in Cairo-Suez area M L

	Serial	Date	Origin Time	Longitude Latitude Depth Magnitude
	no.	(Y/M/D)	(GMT)
	1	19740429	20:04:38	30.5	31.7	33	4.6
	2	19840329	21:36:06	30.18	32.1	10	4.6

Table 6 :

 6 The focal mechanisms parameters of in Cairo-Suez area

			Plane 1			Plane 2		P-axis	T-axis
	Serial no.	Strike Dip	Rake	strike Dip	Rake	Tr. Pl Tr. Pl.	References
	1	60.92 85.85 -130.02	326	40.20	-6.43	297 36 182 29	CMT Harvard solution
	2	54.59	86	152.47 146.67 62.55	4.51	104 16 7	22	CMT Harvard solution
	3	156.14 80.15	-10	247.86 80.15	-170	112 14 22	0	CMT Harvard solution
	4	290.52 87.04 -130.08	197	40.17	-4.6	167 35 52 30	CMT Harvard solution
	5	60.92 85.85 -130.02	326	40.20	-6.43	297 36 182 29	CMT Harvard solution
	6	90.24 54.25 -85.46	262.5 36.00 -96.28	19 80 177 9	AbouElenean et al. (2004)
	7	117.05 84.90 -141.77	23.04 51.95	-6.49	347 30 244 22	AbouElenean (1997)
	8	94.34 71.5	-89.57	272.98 18.51 -91.29	5 63 184 26	AbouElenean et al. (2004)

Table 7 :

 7 The earthquakes events in Gulf of Aqaba areaM L

Serial no. Date (Y/M/D) Origin Time (GMT) Longitude Latitude Depth Magnitude

	14	19951124	16:43:46	34.74	28.97	10	4.9
	15	19951211	1:32:08	34.75	28.92	19	5
	16	19960103	10:05:26	35.248	28.604	10	4.8
	17	19960108	13:18:00	34.82	29.38	6	3.8
	18	19960116	6:17:00	34.73	29.34	6	4.3
	19	19960204	7:23:00	34.94	29.45	6	3.6
	20	19970510	23:01:48	34.61	28.28	10	4.9
	21	20000308	14:22:25	34.695	28.77	7	4.9
	22	20000406	6:37:34	34.83	28.78	12	4.8
	23	20010207	3:39:00	35.01	29.26	21	4.2
	24	20021110	5:09:45	34.62	28.23	16	3.9
	25	20040922	12:00:23	34.6	28.45	10.3	3.2
	26	20080404	14:05:20	34.75	28.78	6.8	3.7
	27	20091229	6:28:44	34.78	28.71	10.9	3.6
	28	20111021	16:36:41	34.74	28.52	8.2	4.2
	29	20100715	11:25:00	34.846	34.846	22.27	4.4
	30	20111021	12:37:00	34.7344	28.5241	9	3.7
	31	20111021	16:36:00	34.7366	28.5224	8.23	4.2
	32	20111103	11:08:00	34.829	28.0302	4.7	3.78
	33	20111103	11:23:00	35.037	28.0575	15	4.34
	34	20131006	8:44:00	34.6313	28.0575	6.14	3.86
	35	20140130	6:39:00	34.6335	27.775	20.8	3.55
	36	20140315	11:57:00	34.6574	27.8517	11.64	3.5
	1	19851231	19:42:41	34.9	29.13	9	4.8
	2	19930703	23:34:10	34.821	28.864	18	4.7
	3	19930803	12:43:05	34.553	28.729	17	6
	4	19930803	16:33:24	34.08	28.36	15	5.7
	5	19930807	4:55:40	34.626	28.612	10	4.2
	6	19930820	23:09:59	34.612	28.72	2	4.6
	7	19931103	18:39:32	34.65	28.7	7	4.9
	8	19931108	1:06:02	34.65	28.69	8	4.7
	9	19931204	23:34:11	34.799	28.886	10	4.6
	10	19951122	4:15:26	34.73	29.07	18.4	7.2
	11	19951122	12:47:04	34.74	29.3	15	5
	12	19951122	22:16:57	34.21	28.32	15	5.2
	13	19951123	18:07:26	34.48	29.31	15	5.7

Table 8 :

 8 The focal mechanisms parameters of in Gulf of Aqaba zone

		Strike1		Strike 2		P-axis	T-axis
	serial	Strike Dip	Rake	strike Dip	Rake	Tr. Pl	Tr. Pl.	References
	no.
		169.04 64.17 -146.81 63.14 60.48 -30.04	28	41	295	2 AbouElenean
									(1997)
		83.53 71.88 -151.1 343.79 62.66 -20.5	306 33	212	6 CMT Harvard
									solution
		138.72 35.9	-123	357.43 60.54 -68.49 309 67	72	13 CMT Harvard
									solution
		356.13 79.41 -82.81 141.64 12.77 -123.82 275 55	80	34 AbouElenean

Table 9 :

 9 The earthquakes events in North Gulf of Suez M L

	Serial	Date	origin Time	Longitude latitude Depth Magnitude
	no.	(year/M/day)	(GMT)
	1	19830612	12:00:09	33.13	28.55	24	4.8
	2	19921020	1:57:58	33.16	28.51	10	3.8

Table 10 :

 10 The focal mechanisms parameters of in the northern Gulf of Suez

			Plane 1			Plane 2		P-axis	T-axis
	Serial	Strike Dip	Rake	Strike Dip	Rake	Tr. Pl. Tr. Pl. References
	no.
	1	129.14 85.8 -9.96	219.88 80.06 -175.73 84 10 175 4	Morsy et al.
											(2011)
	2	157.17 78.09 -50.7	261.32 40.78 -161.59 105 43 218 23 Morsy et al.
											(2011)
	3	319.71 53.06 -98.95	154.39 37.86 -78.32	195 79 56	7	Morsy et al.
											(2011)
	4	154.91 56.97 -66.03	295.71 40	-122	115 68 228 9	Morsy et al.
											(2011)
	5	166.22 61.81 -68.76	306.77 34.76 -124.06 115 66 241 14 Morsy et al.
											(2011)
	6	121.47 76.8 -109.41 358.52 23.33 -35.22	8	54 227 29 Morsy et al.
											(2011)
	7	257.43 52.24 -129.23 130.57 52.24 -50.77	104 60 14	0	AbouElenean
											(2007)
	8	119.77 46.19 -74.67	278.16 45.9	-105.41 108 79 199 0.1 AbouElenean
											(2007)
	9	322.63 51.85 -70.6	112.95 42.12 -112.92 291 74 39	5	Morsy et al.
											(2011)
	10	259.5 73.44 -148.17 159.46 59.63 -19.29	123 34 27	9	Abdelazim et al.
											2016
	11	189	59	-61	322	41	-129	148 63 101 10 Badreldin, (2016)
	12	284	67	-32	28	61	-154	244 38 -23	4	Badreldin, (2016)
	13	193	69	-30	28	61	-156	152 36 -115 4	Badreldin, (2016)
	14	171	55	-21	273	73	-143	137 38 39	11 Badreldin, (2016)
	15	275	79	-124	169	36	-19	150 45 31	26 Badreldin, (2016)

Table 12 :

 12 The focal mechanisms parameters of in the southern Gulf of Suez

			Plane 1			Plane 2		P-axis	T-axis
	Serial	Strike Dip1	Rake	strike	Dip	Rake	Tr. Pl. Tr. Pl.	References
	no.
	1	14.57 27.1	154.81 127.29 78.82	65.15	227 10 26 32	Salamon et al.
									(2003)
	2	153.95 62.9	52.2	33.52 45.30	140.14 270 10 15 55	Salamon et al.
									(2003)
	3	293.65 37.01 -89.08 112.51 52.99	-90.69	19 82 203 8	Huang and
									Solomon (1987)
	4	164.45 79.88 -24.05 258.94 66.34	-168.94 119 24 214 9	Salamon et al.
									(2003)
	5	286.02 44.96 -118.81 286.02 44.96	-118.81 133 70 313 20	Salamon et al.
									(2003)
	6	153.5	90	-17.16	243.5 72.84	-180	107 12 200 12	Salamon et al.
									(2003)
	7	333.32 79.98 -86.05 131.67 10.77	-111.3	248 54 60 34	Salamon et al.
									(2003)
	8	159.77 25.04 -79.69 328.42 65.39	-94.78	229 69 62 20	Salamon et al.
									(2003)
	9	92.55 59.27 -44.54 209.24 52.92	-140.17	58 52 152 4	Badawy and
									Horvath (1999)
	10	288.29 40.28 -99.46 120.61 50.38	-82.07	75 82 205 5	Huang and
									Solomon (1987)
	11	143.88 79.63 -159.24 49.98 79.63	-159.24	8 22 276 7	Hussein (1989)
	12	288.15 70.78	9.46	195.01 160.54	81.08	243 7 150 20	Salamon et al.
									(2003)
	13	321.09 88.81 -50.41	52.52 39.61	-178.14 264 34 19 32	AbouElenean
									(1997)
	14	270.14 46.66 -139.63 149.88 61.90	-51.08	111 55 213 9	Abdel Fattah
									(1999)
	15	154.97 44.19 -80.15	46.63 321.37	-99.44	160 83 58	1	Abdel Fattah
									(1999)
	16	125.75 78.02 -49.23 229.28 42.20	-162.01	74 42 186 22	AbouElenean
									(1997)
	17	81.45 51.85 -83.79 251.46 38.58	-97.84	25 82 167 7	Megahed (2004)
	18	146.31 47.79 -69.58 297.32 46.04	-111.04 129 75 222 1	R Abdel Fattah
									(1999)
	19	133.6 60.48 -98.76 330.98 30.68	-74.94	105 31 12	5	AbouElenean
									(1997)
	20	317.79 64.72 -172.17 330.98 30.68	-74.94	22 73 230 15 Megahed (2004)
	21	323.89 79.21 -140.6 225.15 51.43	-13.86	192 35 89 18	AbouElenean
									(1997)
	22	246.91 61.15 -20.63	347.2 72.02	-149.52 210 34 115 7	AbouElenean
									(2003)
	23	94.12 62.97 -130.75 336.31 47.56	-38.01	314 53 212 9	AbouElenean
									(2007)
	24	29.39 39.36 -134.4 261.09 63.06	-60.15	212 59 331 11	ENSN

Table 13 :

 13 Historical earthquakes list in the northern Egypt and Eastern Mediterranean region

	Serial no.	Date	Lat	Long.	probable I Am	Ms Mw Reference
	1	2200 B.C.	30.75	31.5	7		Badawy 1998 after Seiberg 1932 and Maamoun 1984
	2	1210 B.C.	22.5	31.5	6		Badawy 1998 after Seiberg 1932
	3	600 B.C.	25.55	33	5		Badawy 1998 after Seiberg 1932
	4	220 B.C.	36.5	28.2		7.2	Soloviev et al.,2000
	5	227 B.C.	36.36 28.15		7.5	Soloviev et al.,2000
	6	142 B.C.	36.7	28		7	Soloviev et al.,2000
	7	95 B.C.	30.7	32.5	4	5.2	Ambarseys et al.,1994
	8	23±3BC	38.15 22.14			Ambrayseys 2009
							Reches and
	9	31 BC	31.75	35.5		6	Hoexter,1981,Guidoboni,1994,
							Ambraseys2009
		53/01/ 24 OR 25 AD	35.2	25.1			Ambraseys 2009
		115 AD	35.15 36.27		7.4	Ambraseys2009, Guidoboni1994, Meghraoui et al.,2003
		222	36	28	5		Ambrasey N., 1962
		320 AD	31.5	30	7	6	Ambraseys 1994
		365/07/12	35.25	23.6		7.5-8	Ambraseys 1994, Papadimetriou 2008
		520/10/14	31	31	7	5.8 Ambraseys 1994
		551/7/09	34	35		7.2	Elias et al.2007 & Anna Fokaefs 2005
		554/10/14	32	30			Guidoboni 1994
		749/01/18	32.8	35.5		7.3	Guidoboni 1994, Ambraseys2009, Reches and Hoexter 1981
		794/04/14	36	26	6		Badawy 1998, Ambraseys 1994, Gudoboni 1994
		796/04	32	30		6	Maamoun et al.(1984)
		857/04/30	30	31	9		Ambraseys 1994, Gudoboni 1994
		885/11/06	30.1	31.2	9		Ambraseys 1994, Gudoboni 1994
		859/01/27	30.5	31.5			Badawy 1998
		912	30	31	9		Ambraseys 1994, Gudoboni 1994
		935/10/4	30.5	31.2	9		Ambraseys 1994, Gudoboni 1994
		950/07/25	30.2	31.2	9		Ambraseys 1994, Gudoboni 1994
		963/05/12	35	26		5.4 Ambraseys 1994, Gudoboni 1994
		951/09/15	32	30	9		Ambraseys 1994, Gudoboni 1994
		956/1/1	34	32	7		Ambraseys 1994, Gudoboni 1994
		963/05/12	35	26	6		Ambraseys 1994, Gudoboni 1994
		1068/03/18	29.65	35	7	6.6	Zilberman et al.,2005, Ambraseys 2009
		1091/02/12	28	34	7		Ambraseys 1994, Gudoboni 1994
		1170/06/29	33.15 36.27		7.2	Meghraoui et al.,2003, Maghraoui 2016
		1068/03/18	29.65	35		6.6	Zilberman et al.,2005, Ambraseys 2009
		1091/02/12	28	34	7		Badawy 1998, Ambraseys 1994

Table 14 :

 14

	No.	Date	Time	Long.	Lat.	Depth	Mw
	1	19650427	14:09:00	23.5	36.6	13	5.5
	2	19910626	11:43:34	21.04	38.34	22	5.2
	3	19590709	3:11:00	25.8	36.7	22	7.5
	4	8/17/1982	22:29.8	22.9	33.7	23.4	6.3
	5	5/28/1998	33:33.4	27.36	31.39	39	5.5
	6	4/5/2000	36:58.0	25.83	34.08	15	5.5
	7	2/20/2008	27:11.0	21.8	36.31	22.1	6.2
	8	7/15/2008	26:44.5	27.34	35.92	34	6.4
	9	10/12/2013	11:56.3	23.37	35.37	15	6.8
	10	8/29/2014	45:06.0	23.65	36.49	100.3	5.8
	11	4/16/2015	07:44.0	26.81	35.03	26.1	6.2
	12	7/27/1997	07:52.5	21.064	35.582	13	5.7
	13	3/28/2008	16:19.9	25.39	34.89	52	5.7

Table 15 :

 15 The focal mechanisms parameters of in the Hellenic arc

	No.	Strike	Dip	Rake	References
	1	191	64	-79	Liotier 1989
	2	-105	354	41	Louvari 2000
	3	55	40	-90	HRVD
	4	36	57	88	HRVD
	5	154	44	89	HRVD
	6	109	48	99	HRVD
	7	250	83	-7	MED_RCMT
	8	262	84	-41	NEIC
	9	119	88	88	GCMT
	10	265	70	170	MED_RCMT
	11	65	28	12	MED_RCMT
	12	62	80	-175	NEIC
	13	99	50	103	MED_RCMT

Table 1 :

 1 Major earthquakes of the eastern Mediterranean with tsunami wave records in northern Egypt. Estimated magnitudes are given in Mw when calculated and in M when estimated.

		Epicentre	Estimated Magnitude	Comment	Reference
					Stiros and Drakos,
	21 July 365	Western Crete	8.3 8.5 (M w )	Tsunami northern Egypt	2006; Shaw et al., 2008,
					Hamouda 2009
	18 Jan. 746	Dead Sea Fault	7.5 (M)	Tsunami eastern Medit.	Sieberg, 1932, Ambraseys, 1962
				Tsunami in
	881 -882	Palestine	?	Alexandria &	Galanopoulos A., 1957
				Palestine
	4 Jan. 1033	Jordan Valley Fault	7.4 (M)	Tsunami northern Egypt	Ambraseys, 1962
	18 Jan. 1068	Northern Lebanon	6.9 (M)	Waves in Lebanon Until northern Egypt	Ambraseys, 1962, Soloviev et al., 2000
	8 Aug. 1303	Karpathos & Rhodos islands	8 (M)	>8-m-high wave in Alexandria	Abu al-Fida 1329, Ambraseys 2009, Hamouda 2006
	24 June 1870	Hellenic Arc	M L 7.2	Inundation in Alexandria harbour	Ben-Menahem, 1979, Soloviev et al., 2000

Fig.57: Description of core no.6 with photography, x-ray scanning, detail description of lithology, mean grain size, sorting, total organic and inorganic matter and bulk mineralogy. The core is at 320 m from the shoreline and reveals 3 main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2) and organic matter are interpreted as deposits of tsunami origin.

main layers (see numbers and pointed hands) of high energy deposits with coarse sand and mixed clay and organic matter. The layers with high values of magnetic susceptibility (especially for 1 and 2) and organic matter are interpreted as deposits of tsunami origin.

Acknowledgments

We are grateful to Prof. Hatem Odah, Dr. Assia Harbi, Adel Samy, Hany Hassen, Mohamed Maklad, Mohamed Sayed and NRIAG administration and staff for their keen efforts and help during the development of this work. We are grateful to the North African Group for Earthquake and Tsunami studies (NAGET) for support. The Centre d'Etudes Alexandrines helped with the lending of the COBRA instrument for coring. Special thanks to the Egyptian Armed Forces for issuing permissions and their support during field work. This work is conducted in the framework of the EC-Funded ASTARTE project (Assessment, Strategy And Risk Reduction for Tsunamis in Europe -FP7-ENV2013 6.4-3, Grant 603839) and the French-Egyptian IMHOTEP project.

National Insitute of geophysics and Astronomy NEIC: National Earthquake Information Center ENSN:Egyptian National Seismology Network CMT: Harvard Centroid Moment Tensor Catalog GFZ: German Research Centre for Geosciences

Hussein, H.M., (1989). Earthquake activities in Egypt and adjacent regions and its relation to geotectonic features in A.R.E. MSc. Thesis. Fac. of Sci., Geology Dept., Mansoura University, Egypt.

Hussein, H., Korrat, I.M and Abdel Fattah, A. K., (1996). The October 12, 1992 Cairo earthquake a complex multiple shock. Bull. Int. Inst. Seis. Earthquake Eng., Vol. 30, p.9-21.

Hussein, H.M., (1999). Source process of October 12, 1992 Cairo earthquake. Ann. Geofis. Vol. 42 no.4, p.665 675.

Hussein, H.M., Korrat, I.M., El Sayed, A., (2001). Seismicity in the vicinity of Alexandria and its implications to seismic Hazard. In: Second International Symposium on Geophysics, 19 20 February 2001. Faculty of Science, Tanta University, Tanta, p. 57 64.

Hussein, H, M., Abu Elenean, K. M., (2008). Source parameters of the significant earthquakes in Egypt, 1992Egypt, -1998 Ibrahim, E.M. and Marzouk, I., (1979). Seismotectonic study of Egypt. Bull. Helwan Inst.

Astro. and Geophysics.

Imamura, F., (1997). Numerical Method of Tsunami Numerical Simulation with Leap-Frog Scheme. Time Project. IUGG/ IOC, UNESCO, Paris IRIS . Incorporated ReserchInstitutation for seismology, http://ds.iris.edu/seismon.

Ishimura, Daisuke and Takahiro Miyauchi. (2015). Historical and Paleo-Tsunami Deposits during the Last 4000 Years and Their Correlations with Historical Tsunami Events in Koyadori Planetary Science Vol.2 no.1-16. Retrieved (http://www.progearthplanetsci.com/content/2/1/16).

Ismail, A., (1960). Near and local earthquakes at Helwan from 1903-1950, Helwan , Helwan Observatory Bull. No. 49.

Jackson J, McKenize D. (1984). Active tectonics in the Alpine Himalayan belt between western Turkey and Pakistan. Geophys J R Astron Soc Vol. 77, p.185 246. (2009). Heavy minerals in 2004 tsunami deposits on Kho Khao Island, Thailand. In: Polish Journal of Environmental Studies Vol.18 no.1, p. 103 110. Jones, J. O. (1925). A method for determining thr degree of humification of soil organic matter, jour.AGR. SCI.

[ENGLAND] VOL..15, P. 26-29.

Kebeasy, R.M., Maamoun, M., Ibrahim, E., Megahed, A., Simpson, D.W., Leith, W.S., (1987). Earthquake studies at Aswan reservoir. J. Geodyn. Vol. 7,p.173 193. -14.9402 -23.1475 -29.6635 -30.489 -37.904 -39.3286 -45.4036 -45.1256 -52.6906 -53.0035 -60.471 -62.4826 -69.5653 -70.2672 -72.6202 -77.4703 -79.106 -81.4544 -84. -5.575 -16.6638 -22.7062 -25.516 -28.661 -33.7841 -36.9286 -44.6097 -44.1871 -51.9217 -55.3367 -55.4225 -60.2962 -63.9697 -67.4114 -69.4325 -72.2006 -75.8761 -75 .3699 -9.571 -18.5933 -21.092 -23.2785 -35.7834 -64.1294 -77.3933 -81.2924 -82.427 -87.9229 -90.5257 -96.2952 -96.2553 -101.2952 -96.2236 -96 1980). From the moment tensor the orientation and sense of slip of the fault is resolved.

APPENDICES

Paleotsunami methodology 2.1. Grain size equations

This following equations of calculate mean size, sorting, Skewness, Kurtosis according to Folk (1968). Abstract.

We study sedimentary record of past tsunamis along the coastal area west of Alexandria (NW Egypt) taking into account the reported historical inundations and related major earthquakes v4.2.4 (Bronk-Ramsey, 2013).

Cores at El Alamein: The 12 cores extend between 1 and 2.6 m depth and except for cores 1 and 9 which are in Figures 4 a and b, all stratigraphic logs are presented in the supplemental material S2. The core descriptions are as following:

Core 1: This core is located at ~166 m from the shoreline (Figure 2), east of the study area behind the sand dunes and near the outlet of the seawater. The core depth reached ~2.14 m and the stratigraphic section includes 3 tsunami layers recognized as following (Figure 4 a section 1): The first layer is at ~12.5 cm depth with ~34.5 thick, brown clay sediments with poor sorting, fine gain sediments, with high peak in magnetic susceptibility, rich in organic matter, and X-ray image reflects clear lamination. The second layer at ~70 cm depth has ~5 cm thickness, characterized by highly broken shells fragments with extremely bad sorting of sediments granulometry. The third layer at ~75 m depth is ~22 cm thick, pale yellow sand with extremely bad sorting of sediments size, with peak in magnetic susceptibility. The chemical analysis shows the presence of gypsum and minor goethite, and X-ray scanning shows some turbiditic structures in these sediments. A fourth tsunami layer is identified at 158 cm (see also Fig. S2- 2b). This first and uppermost sample is located within a sedimentary unit of tsunami origin characterized by bad sorting, highly broken shells fragments and peak of magnetic susceptibility. The second sample is a rodent bone at 50 cm depth and provides 403 -603 AD calibrated age which may correspond to a position in between two tsunami deposits in stratigraphic succession 1 and 2 that may be correlated with the tsunami events of 8 August 1303 above and 21 July 365 below.

Core 2:

As shown in Fig. S2 -1 core 2 is ~90 cm deep located south of core 1 at ~264 m from the shoreline. Two tsunami layers are recognized. The first tsunami layer of brown clay sediments is at ~12.5 cm depth ~12.5 cm thick with extremely bad sorting, corresponding to a small peak at magnetic susceptibility. The layer is rich in organic matter (> 1) comparable with other layers of this core; the geochemical analysis shows minor component of goethite.

The second layer is at ~50 cm depth ~15 cm thick, made of yellow sand with silty-clay pockets, rich with broken shells fragments, extremely poor sorting and with peak magnetic suc. It is rich in organic matter comparing to other layer, and the geochemical analysis shows minor component of halite.

Two shell (gastropod) samples were collected at 75 cm and 77 cm depth and have calibrated dates 32971 -34681 and 34362 -36931 BC, respectively (Table 2b). These two samples are located in the bottom of the tsunami stratigraphic layer 2 (Fig. S2-1). However, their old age may well be due to a reworked sedimentation during the catastrophic tsunami event.

Core 3: This core is located at 270 m from the shoreline and the outlet of sea water as shown in Fig. S2 -3. The first tsunami layer is at ~25 cm depth and corresponds to a 26 cm thick pale brown clay with sorted sediments; it is characterized by highly broken shells fragments and sediments rich in organic matter. The second layer at ~70 cm depth is 17.5 cm thick; it is characterized by white sand with laminations at the top and fine sediments at the bottom, with peak of magnetic susceptibility near zero value, and with high organic matter > 2. The third tsunami layer at 106 cm depth is 32 cm thick, characterized by yellow sand with minor illite and broken shells fragments.

Two shell samples were collected for dating at 37 cm and 45 cm depth and show calibrated dates 43618 BC and 34218 -37224 BC respectively (Fig. S2-2 and Table 2b).

These two samples are located within the stratigraphic tsunami layer 2 and may correspond to reworked sediments due to the high energy sedimentation during the catastrophic event.

Core 4: It is located at 435 m from the shoreline and shows stratigraphic units characterized by two tsunami layers (Fig. S2 -4). The first tsunami layer is white sand at ~12.5 cm depth 7 cm thick with highly sorted sediments. It also shows high broken shells fragments with organic matter > 2. The third tsunami layer is a 35 cm thick pale yellow sand at ~102 cm depth. It is also characterized by yellow sand with minor amount of illite and gypsum and broken shells fragments.

One shell sample collected for dating at 37 cm depth provides a calibrated date 32887 -34447 BC respectively (Table 2b). This sample located in the stratigraphic tsunami layer 1 (Fig. S2-3) apparently results from high energy reworked sedimentation during the catastrophic event (Fig. S2-4).

Core 5: This is the southernmost core in the El Alamein site at 490 m distance from the shoreline (Fig. S2 -4). The core reaches 73 cm depth and the sedimentary succession does not show any possible sedimentary catastrophic layer of tsunami origin. According to its content, core 5 may show the limit of inundation area with respect to at least the first and second tsunami layers.

One shell (gastropod) sample collected for dating at 50 cm depth provides 442182 -448237 BC calibrated age (Table 2b). The relatively old age of the sample may refer to transportation and reworking due to high current waves during a tsunami event.

Core 6: This core is located south of the sand dunes at 320 m from the shoreline. It is characterized by three tsunami layers (Fig. S2 -5). The first tsunami layer is a pale yellow sand with broken shells fragments at ~5 cm depth and ~24 cm thick with highly sorted sediments rich in organic matter larger than 2.5. The second tsunami layer is at ~58 cm depth ~18.5 cm thick characterized by yellow sand with a minor amount of gypsum and Illite. The third tsunami layer at 130 cm depth ~20 cm thick characterized by white sand with minor amount of goethite and broken shells fragments. It is very rich (larger than 3) in total weight of organic matter. Black pdfs refer to the dated samples and red pdfs are simulated dating of three tsunami records. The sedimentary record is correlated with the historical earthquake and tsunami catalogue of the eastern Mediterranean [START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF][START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF]Ambraseys, 2009).

Three samples were collected for dating in core 6. The first sample is a gastropod at ~45 cm depth and shows 35002-37441 BC calibrated date. The second and third samples are coral fragments at ~60 cm and ~80 cm depth that show 42776-69225 BC and modern (younger than 1650 AD) calibrated ages, respectively. The first sample is above the stratigraphic tsunami layer 2 while the second sample was within the stratigraphic tsunami layer 2 (Fig S2 -7). These samples may result from reworking due to high current waves transport of tsunamis.

Core 7: This core was located at 273 m from the shoreline. It characterized by stratigraphic units with soft sediments with three tsunami layers within 120 cm depth (Fig. S2 -6). The first tsunami layer is brown sand with broken shell fragments at ~14 cm depth 6 cm thick with highly sorted sediments. It is characterized by rich with organic matter > 2 and noticeable Black pdfs refer to the dated samples and red pdfs are simulated dating of three tsunami records. The three sedimentary records are correlated with the historical earthquake and tsunami catalogue of the eastern Mediterranean [START_REF] Guidoboni | Catalogue of Ancient Earthquakes in the Mediterranean area up to the 10th century[END_REF][START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF]Ambraseys, 2009).

Core 8: This core is located at 214 m from the shoreline. Three tsunami layers are recognized (Fig. S2 -7). The first tsunami layer is a pale silty clay at ~14 cm depth 16 cm thick with high organic matter and minor amount of goethite. It is characterized by highly broken shell fragments and rich in organic matter. The second layer at 52 cm depth and 22 cm thick characterized by pale yellow silty-clay, with low peak of magnetic susceptibility and high organic matter >2.5. The third tsunami layer at 128 cm depth is 9 cm thick characterized by pale yellow sand with highly angular gravel sediments, badly sorted and broken shells fragments. No samples were suitable for dating in this core.

Core 9: It is located at 130 m from the shore line. Three tsunami layers are recognized (Fig. 4 b). The first tsunami layer is white sand at ~16 cm depth and 13 cm thick with high content of organic matter and rip up clasts that appear in X-ray scanning characterized by highly broken shells fragments and rich in organic matter. The second layer at 67 cm depth is 22 cm thick characterized by white sand, with a peak of magnetic susceptibility, high content of organic matter larger than 5. The third tsunami layer at 139 cm depth is 14 cm thick characterized by broken shells fragments and white sand with highly angular sediments that reflect the bad granulometric sorting.

Two samples were collected for dating in core 9. The first sample is a gastropod located at 24 cm depth within the tsunami layer 1 provides 1052-1888 BC calibrated age. The second sample at 55 cm depth is a bivalve (lamellibranch) located below the stratigraphic tsunami layer 1 (and above the tsunami layer 2) dated at 40521-43169 BC calibrated age.

These samples may have been transported and sedimented in reworked units due to high current waves of tsunami.

Core 10: It is located at 245 m from the shoreline. Three tsunami layers are recognized (Fig. S2 -8). The first tsunami layer is a brown silty clay at ~19 cm depth 9 cm thick, with highly organic matter and with rip up clasts and lamination that appear in X-ray scanning. It is characterized by high broken shells fragments and rich in organic matter > 4. The second layer at 48 cm depth and 38 cm thick is characterized by brown sand with broken fragments of shells, with peak of magnetic susceptibility, and high organic matter > 1.5 at the bottom of the layer. The third tsunami layer at 101 cm depth is 28 cm thick characterized by pale yellow sand with high organic rich matter and sediments that reflect the bad sorting.

Two samples were collected for dating in core 10. The first sample located in the stratigraphic tsunami layer 1 is a shell fragment at 24 cm depth that provides 2623 -3521 BC calibrated age. The second sample located in the stratigraphic tsunami layer 2 is a rodent bone at 70 cm depth showing 41256-46581 BC calibrated age (Table 2b). Both samples may result from reworked sedimentary units due to high current waves of tsunami events.

Core 11:

It is located at 151 m from the shoreline. Three tsunami layers are recognized (Fig. S2 -9). The first tsunami layer is a white sand at ~19 cm depth 10 cm thick, with highly organic matter and characterized by high broken shells fragments and rich in organic matter > 4 with high weight percent of gypsum 50%. The second layer at 76 cm depth 9 cm thick characterized by white sand, with broken fragments of shells, with peak of magnetic susceptibility with organic matter larger than 1.5. The third tsunami layer at 107 cm depth with 21 cm thick characterized by grey silty and sediments reflect the bad sorting and high organic rich matter with minor amount of Illite and gypsum.

Eight samples were collected for dating in core 11. The first sample is a gastropod at 20 cm depth and shows 3638-4328 BC calibrated age. The second sample is a shell at 62 cm depth with a calibrated date of 3710-3943 BC (Table 2 b). These two samples are found in the stratigraphic tsunami layer 1 and 2 respectively (Fig. S2-9). They may correspond to transported samples in reworked sediments due to high wave current of tsunami.

The third, fourth and fifth sample are gastropods found at 116 cm, 121 cm and 126 cm depth with calibrated date 2619-3386 BC, 2457-3366 BC and 2477-3368 BC, respectively.

The sixth sample is a shell found at 152 cm depth with calibrated date 33294-36120 BC. The seventh sample corresponds to roots found at 139 cm depth with 2666-2817 BC calibrated age. The eighth sample is a charcoal found at 180 cm depth with calibrated date 3710-3943 BC (Table 2b). Except for sample 6, samples 3 to 8 belong to sediments with chronological sequence from 2457 to 3943 BC. The six samples are seemed to be transported by high wave current of tsunami.

Core 12: It is located at 127 m from the shoreline. Three tsunami layers are recognized (Fig.

S2 -10). The first layer is ~7.5-cm-thick at ~19-cm-depth and is made of poorly sorted white sandy deposits, and highly broken gastropods and lamellibranch fossils. The high value of organic matter and high peak of magnetic susceptibility reflect a rich content in carbonates and quartz. The second layer is ~13-cm-thick at ~32.5-cm-depth characterized by white sandy deposits intercalated with coarse brown sand horizontal lamination, poor sorting sediments, rich in total organic matter and high peak of magnetic susceptibility. The third layer is ~25cm-thick at 89-cm-depth made of grey sandy clay, with laminations at the bottom of deposits, vertically aligned gastropods, broken shells fragments, rich in total organic matter and pyrite showing high peak of magnetic susceptibility. A fourth tsunami layer is identified at 151 cm depth core bottom. It is characterized by pale yellow sand, medium to fine, with broken shells fragments and extremely poor sorting, with high peak of magnetic susceptibility, high peak of organic matter > 5.5 and high amount of gypsum.

Five samples were collected for dating in core 12. The first sample is a gastropod found at 44 cm depth with a calibrated date at 3367-3366 BC. The second sample is a shell found at 108 cm depth and shows 3097-3950 BC calibrated age (Table 2b). The third sample is a gastropod found at 114 cm depth with calibrated date 3331-4050 BC. The fourth sample is a shell found at 117 cm depth with calibrated age 39560-40811 BC. The fifth sample is a gastropod found at 135 cm depth with calibrated age 3365-4071 BC (Table 2b). The first and fourth samples appears off sequence with respect to the other samples and may result from sediment transport and reworking due to high energy tsunami waves. The other samples are in sequence from 2457 to 4071 BC ages comparable to the sedimentary succession of core 11.

Summary of results from trenching and coring

The cores and trenches in both Kefr Saber and Alamein sites show three main layers characterized by fine and coarse sand mixed with broken shell fragments that indicate the occurrence of high energy sedimentary deposits in the coastal lagoon environment (Figs. 2 a and b, and Fig. 3). A remarkable observation is the very similar white sandy layer with broken shells found in trenches (see Fig. 3) and in cores with ~200 km apart that we interpret as tsunami deposits due their sedimentary signatures (see details of core descriptions above).

According to the radiocarbon dating, this layer may be correlated with the 21 July 365 earthquake in western Crete and related tsunami (Figures 5 a andb).

In most cores (Figs. 4 a and b, and Fig. S2), the first tsunami layer is ~7.5-cm-thick at ~19 cm-depth and is made of poorly sorted white sandy deposits with high broken gastropods and lamellibranch (shell) fossils. The high value of organic matter and high peak of magnetic susceptibility reflect a rich content in carbonates and quartz. The second layer is ~13-cm-thick at ~32.5-cm-depth characterized by white sandy deposits intercalated with coarse brown sand horizontal lamination, poor sorting sediments, rich in total organic matter and high peak of magnetic susceptibility. The third layer ~25-cm-thick at ~89-cm-depth is made of grey sandy clay, with laminations at the bottom of deposits, vertically aligned gastropods, broken shells fragments, rich in total organic matter and pyrite showing high peak of magnetic susceptibility.

In a synthesis of all dated units in trenches and cores, the sedimentary succession provide evidence for the identification of three tsunami deposits with their ages using radiocarbon dating at Kefr Saber and El Alamein sites (Figs 5 a and b). In the case of Kefr Saber trenches (Fig. 5 a and Table 2 a), the dating of charcoal fragments allows the bracket of a tsunami event between AD 30 120 (sample TSU P5 S3) and AD 820 1020 (sample TSU P3 S2). From the dating sequence, and using the Oxcal Bayesian analysis (Bronk-Ramsay,

2001

) we obtain a simulated age of the tsunami event between AD 137 and AD 422, which includes the AD 365 western Crete earthquake. The dating of sedimentary units at the El Alamein site turned out to be more complex due to the reworked sedimentation with significant alluvial deposits (see the large number of dating larger than 30 ka BC in Table 2 b). The radiocarbon dating (including the Oxcal Bayesian analysis) of shells, bone and charcoals fragments at El Alamein site result in a sequence of ages that allow the bracket of an event X between AD 48 and AD 715, and event Y between AD 1168 and AD 1689, and an event Z between AD 1805 and AD 1935 (Fig. 5b). The three simulated dates of the three tsunami events X, Y and Z include the seismogenic tsunamis of AD 365, AD 1303 and AD 1870. The three main layers visible in trenches and cores have physical and chemical characteristics that correlate with high energy environmental conditions of tsunami deposits.

The three high magnetic susceptibility peaks of the three deposits also correlates with the high value of organic matter and carbonates. We also observe poorly sorted sediments greater than 5 in the three layers that according to Folk (1968) mark high energy deposits and tsunami records.

The modelling of tsunami waves

The tsunami issue is particularly urgent for the Mediterranean countries that are known to have been affected by tsunamis in the past, several of which had catastrophic size and impact (Papadopoulos et al., 2014). Previous numerical studies of tsunamis modelling and estimation of the wave height runup and the time of wave arrival on a given coastline have been presented for the Hellenic arc (Shaw et al., 2008;Hamouda, 2006Hamouda, , 2009;;Tinti et al., 2015;[START_REF] Necmioglu | Earthquake scenario-based tsunami wave heights in the eastern Mediterranean and connected seas[END_REF]. These studies present different results due to two reasons: a) the bathymetry data with various resolutions are used in the modelling, and b) the fault rupture and surface deformation with various parameters used in these modelling studies.

Fault dimension Values

Here, we present the modelling of wave propagations with two simple scenarios of earthquake-generated tsunamis in the eastern and western Hellenic subduction zone (Fig. 7).

For each scenario, we take into account a seismic fault capable of generating an earthquake with magnitude Mw equal to or larger than the highest magnitude (Mw ~ 8.5) consistent with the evaluated earthquake size from historical catalogues (Tables 3 and4; [START_REF] Stiros | The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data[END_REF]Shaw et al., 2008;Papadopoulos et al., 2014). The computation is based on the nonlinear shallow water theory using the Mirone software update version 2.7.0, modified on 22 October 2016 (Madder, 2004;Luis, 2006). The digital bathymetric data of the Eastern Mediterranean was obtained from the bathymetric chart of Intergovernmental Oceanographic Commission 2014 [START_REF] Gebco | Digital Atlas published by the British Oceanographic Data Centre on behalf of IOC and IHO[END_REF]. We use these fault parameters and the Okada (1985) dislocation model in order to create the initial tsunami wave. In this study, grids represent the GEBCO bathymetry (30 arc seconds, 2003) and another grids contains the initial deformation as produced by the dislocation deformation module.

Fault dimension Values

In both scenarios, we consider an Mw 8.5 (as worst case) earthquake generated on 3 and4) of the eastern and western seismogenic segments of the Hellenic subduction zone determine the tsunami initial conditions and associated seafloor coseismic deformation with a 35 m maximum and -15 m initial water elevations (Fig. 7). Snapshot images of Figure 7 obtained from the modelling simulation show the tsunami field wave propagations computed every 0, 16, 33, 66, 100, 150 minutes after the tsunami initiation. Our observations indicate that all the Egyptian coastline is affected by tsunami waves but with relatively short time (~50 mn) wave propagation and larger (4 to 10 m) wave heights in the case of the eastern Hellenic arc seismic source (e.g., AD 1303 earthquake). In the case of the west Crete seismic source, major wave arrives at the Egyptian coast after 100 minutes with 0.86 1.76 m wave height at Kafr Saber site and with 0.50 m wave height at the El Alamein site.

In comparison with the paleoseismic results, the modelling indicate that both Kefr Saber and El Alamein sites recorded the past tsunamis, but with the latter site being better exposed to the eastern Hellenic source of tsunamis than to the western source. In contrast, the Kefr Saber site has a better record of the western Crete tsunami due to its proximity to the western Hellenic seismic sources.

Discussions and Conclusions

The identification of tsunami deposits within the stratigraphic layers and results of radiocarbon dating allow the chronological simulation of the three tsunami events (Figs. 5 a and b). Indeed, the dating of the three high energy sedimentary layers deposited along the Egyptian coastline a Kefr Saber and El Alamein correlate with the seismogenic tsunamis generated on the Hellenic subduction zone. The historical seismicity catalogue of the Eastern Mediterranean reports three significant tsunamigenic seismic events of the Hellenic subduction zone that affected the Mediterranean coast of Egypt: 1) The 21 July 365 earthquake (Mw 8. 3 8.5;Stiros and Drakos, 2006;Shaw et al., 2008), 2) the 8 August 1303 earthquake (Mw 7.8 8.0), and 3) the 24 June 1870 earthquake (Mw 7 -7.5). The size of past tsunamis can be compared with the thickness of catastrophic sedimentary units in trenches of Kefr Saber and core units of the El Alamein site. It appears that the tsunami deposits of the AD 365 tsunamigenic earthquake have a larger thickness at Kefr Saber site than at the El Alamein site. In return, the thickness of sedimentary layers of the AD 1303 and AD 1870 are thicker at the El Alamein site. These observations can be justified by the proximity of the tsunamigenic source in western Crete and AD 365 earthquake with respect to the Kefr Saber site, and the proximity of the AD 1303 and AD 1870 seismic sources in the east Hellenic Arc with regards to the El Alamein paleotsunami site.

The record of past tsunami deposits are favored by the low topography and platform geomorphology along the Egyptian Mediterranean coastline. The coastal environment with similar lagoons and dunes with large areas with relatively flat morphology allowed the deposits of catastrophic marine deposits intercalated within alluvial deposits. The lagoon shapes elongated along the shoreline at Kefr Saber and El Alamein sites explain the similarity between the sedimentary units and the tsunami deposits. The correlation between the core deposits at El Alamein and trench deposits at Kefr Saber is marked by the dating of tsunami deposits and the correspondence with the AD 365 earthquake. The succession of sudden highenergy deposits with low energy and slow sedimentation may include reworked units with disturbance in their chronological succession. In comparison with the trench results of Kefr Saber, the sedimentary sequence from cores at El Alamein reveals mixed old and young dates likely due to the sedimentary environment with large lagoon and nearby topography with the supply of colluvial and alluvial deposits. Despite the richness of the sediment content in charcoal fragment, bones and shells, the reworking imply significant out of sequence dating and large uncertainties (see table 2 b with 12 dating with ages > 30 ka among 30 samples).

Although the results of dated shells would have been suspicious (due to the unclosed mineralogical system), their consistency is pointed out with the comparable nearby radiocarbon dating. On the other hand, 3 modern ages from the Kefr Saber trench units affected the final results of tsunami layer determination.

The study of paleotsunami deposits represents an insight into the occurrence and size of future tsunamis with an estimate of wave heights. Our modelling reveal 4 to 10 m high wave reaching the Egyptian coastline after 50 minutes (Fig. 7) in agreement with the historical seismicity catalogue that indicate the occurrence of great damage in Alexandria region with coastal flooding and inundations. Although the constraint of tsunamigenic seismic sources along the Hellenic subduction zone may include large uncertainties, the changes in the parameters of coseismic ruptures do not affect significantly effect the wave propagation (timing) and heights (less than 20%). The 800 years estimated recurrence time of coseismic slip along the Hellenic subduction zone (with ~5000 years return period for each rupture segment; Shaw et al., 2008) implies the repetition of tsunami catastrophes and the possibility for a forecast programme in the East Mediterranean regions [START_REF] Titov | Realtime tsunami forecasting: challenges and solutions[END_REF][START_REF] Gunatilake | The Indian Ocean megatsunami of December 2004: the scientific basis of the Catastrophe[END_REF]. These results taking into account the mitigation of tsunami catastrophes along coastline Egypt.

Supplementary data (See Chapter IV Palotsunami records in Northern Egypt)

Supplementary data associated with this manuscript are: