Laura Centemeri

Orcid Org

Sezin Topçu

J Peter Burgess

Introduction: Recovery, Resilience and Repairing. For a Non-Reductionist Approach to the Complexity of Post-Disaster Situations

Keywords:

The introduction reviews the most relevant existing approaches to the study of recovery after disaster. It introduces a framework that is based on the analysis of repair processes and dispositifs, which is grounded in the assumption that any disaster situation is marked by the uncertainty of its 'what-ness'. This 'what-ness' depends on the diversity of actors experiencing its consequences and their involvement in a variety of processes of acknowledging, evaluating and managing these consequences at different scales. From this perspective, researching processes of recovery consists in following how the disaster and its consequences are made the object of a variety of struggles around the meaning of what happened and how it affected the given order of things and the possible future. The chapter illustrates how this approach overcomes some of the limitations of a recovery analysis framework that is based on the notion of resilience, pointing to the need to explore the multiple meanings of repairing environments in order to explain how communities recover after disaster. The chapter also highlights three different meanings of repairing in the field of recovery: repairing as redress, repairing as technical fixing and repairing as the everyday maintenance of one's own world in material, multispecies, experiential and emotional terms.

diversity, as the volume will show, is not immediately compatible with an approach to recovery that sees a community disaster as just a technical, logistical or infrastructure problem. In an attempt to revolutionize this monolithic view of human vulnerability and provide it with colour and texture, this book will mobilize the notion of 'repair' and show how it offers the possibility of addressing post-disaster recovery in all its complexity, sociality and humanity.

In the broad and diverse field of disaster research and management, 1 recovery is defined as the process of a return to normalcy, or the 'period of time where deliberate actions are undertaken to routinize everyday activities of those individuals and groups whose daily routines have been disrupted. These activities may restore old patterns and/or institute new ones' (Quarantelli 1999: 3).

Traditional approaches to recovery have been criticized for being limited in their temporal scope and for being poorly equipped theoretically [START_REF] Berke | Recovery after disaster: achieving sustainable development, mitigation and equity[END_REF][START_REF] Passerini | Disasters as agents of social change in recovery and reconstruction[END_REF][START_REF] Weidner | Review of disaster recovery[END_REF]; [START_REF] Tierney | Social Dimensions of Disaster Recovery[END_REF][START_REF] Aijazi | Theorizing a Social Repair Orientation to Disaster Recovery: Developing Insights for Disaster Recovery Policy and Programming[END_REF]. While disaster research on recovery was initially centred mainly on questions relating to the appropriate reconstruction of housing, shelter, resettlement, relocation, displacement and psychological and psychosocial recovery, the field began in the 1990s to address issues such as the roles of institutions, the state and civil society actors in recovery policy-making and implementation. The focus has been on coping strategies, adaptation mechanisms and more recently resilience building. However, the research has rarely addressed questions of social change after disasters through long term studies on recovery outcomes, including the role played by pre-existing socio-economic conditions in shaping post-disaster trajectories. This reveals a still largely dominant understanding of disasters as temporally delimitated phenomena. 2 This book aims at challenging such an approach. In so doing, it aligns itself with a tradition of research on disaster that first emerged in anthropology and then, more recently, in STS studies and that requires us to expand time frames in the study of disasters, to problematize assumptions about the onset of crises and to recalibrate assumptions about the scope and duration of their aftermath (see [START_REF] Oliver-Smith | The Martyred City: Death and Rebirth in the Peruvian Andes[END_REF]Oliver-Smith and Hoffman 1999;Dowty and Allen 2011;Revet and Langumier 2015;[START_REF] Fortun | Researching Disaster from an STS perspective[END_REF]. The book focuses on this process of recalibration as a way to fully understand, on the one hand, the pervasive, longlasting, 'slow' (see [START_REF] Nixon | Slow Violence and the Environmentalism of the Poor[END_REF][START_REF] Knowles | Learning from Disaster? The History of Technology and the Future of Disaster Research[END_REF]) nature of the impact of disaster both on societal or community life and on individuals' environments and their bodies and, on the other, how diverse forms of injustice structurally inscribed in a social fabric can contribute to increasing vulnerability to disastrous events. In addition to social injustice, the recent research on disasters has shown that questions of environmental [START_REF] Schlosberg | Defining Environmental Justice: Theories, Movements, and Nature[END_REF], epistemic [START_REF] Allen | Strongly Participatory Science and Knowledge Justice in an Environmentally Contested Region[END_REF][START_REF] Frickel | On Missing New Orleans: Lost Knowledge and Knowledge Gaps in an Urban Hazardscape[END_REF]) and narrative [START_REF] Barca | Telling the Right Story: Environmental Violence and Liberation Narratives[END_REF] injustice are of crucial importance to understand the specific trajectories of recovery after disaster.

Consequently, the approach to recovery developed in this volume connects with the current debates and recent developments in social theory and takes into serious account the fact that the ways in which we think about disaster have 'profound operational and political consequences' [START_REF] Fortun | Researching Disaster from an STS perspective[END_REF](Fortun et al. : 1008; see also [START_REF] Kreps | Disasters Are Non-Routine Social Problems[END_REF]. In this regard, the contributions collected in this volume all refer, albeit in a diversity of perspectives, to the adoption of relational approaches (like pragmatism) to the interpretation of disaster situations intended as 'problematic situations', in which the moral, epistemic, political and material dimensions are intertwined. As others authors have pointed out (see [START_REF] Go | Postcolonial Thought and Social Theory[END_REF][START_REF] Doucet | Shorelines, seashells, and seeds: Feminist epistemologies, ecological thinking, and relational ontologies[END_REF], relational approaches in social sciences allow for a fruitful dialogue with perspectives inspired by postcolonial theory and 'ontological politics' which are attentive to how divergent knowledges and practices 'make worlds' (see De la Cadena and Blaser 2018).

Recovery and the disputed 'what-ness' of disaster

There is a general agreement in the literature that disasters are social phenomena, regardless of the hazardous agents involved. Phenotypic classifications that distinguish disasters according to agentseparating, for example, natural disasters from technical disasters and public health disasters from ecological disastershave been increasingly contested for their lack of analytical clarity. In line with Perry (2018: 14), a consensus has formed around the definition of disaster as a 'fundamental disruption in the social system (of whatever size) that renders ineffective whatever patterns of social intercourse prevail'. Its 'causes rest in the social structure, social interactions and the environment as a whole' (ibid.: 15, our emphasis).

With regard to its disruption of patterns, a disaster can trigger a 'chain of occurrences' that can potentially result in the long-lasting transformation of previous structures and practices, a defining trait of what [START_REF] Sewell | Historical Events as Transformations of Structure: Inventing Revolution at the Bastille[END_REF] called 'historical events'. 'Historical events' here refer to temporally extended situations that reveal the interplay between action, culture and structures (including material infrastructures and the environment) in the production of social transformation. This book aims at exploring, through a focus on repair processes and dispositifs, how social structures and patterns undergo this transformation, what the causes and correlates of the transformation are and the multilevel reach of its aftermath. 3 In her literature review of 'what we know, or think we know, about long term disaster recovery', Passerini (2000: 67) argued that the transformative potential of disasters is more often than not defused by 'a myriad of structural and cultural forces that keep people from considering or embracing change', while, at the same time, disasters can sometimes overwhelm the capacity of communities to recover. Moreover, when change does occur, it happens on different scales, in a variety of forms, at different rates and in a time span that is impossible to predetermine. Indeed, the transformative potential of a disaster can stay latent until broader conditions for change are in place.

Similarly, the issue of scale is often debated in the literature on recovery, where it is understood in terms of the social level, or unit, from which the 'success of recovery' should be assessed [START_REF] Quarantelli | The Disaster Recovery Process: What We Know and Do Not Know From Research[END_REF]. Disaster recovery is in this sense understood as a finite objective that can be achieved and subsequently dispensed with. It is a measure that remains external to the process, a measure that is determined and imposed by the observer. As a consequence of the focus on 'success' at the expense of 'social change', there is often a lack of perspective and clarity in the assessment. The historical situation and the observer's value projections silently shape the normative underpinnings of disaster management as well as the specific meanings attributed to 'success'. Successful for whom? According to whom? Such questions are often neglected in the managerial approaches to recovery.

This same lack of reflexivity on normative assumptions can be found in the currently fashionable idea of recovery as 'Building Back Better'. This catchphrase was coined by the former US president Bill Clinton in the aftermath of the 2004 Indian Ocean earthquake and tsunami and was developed into a list of 10 propositions conceived as operational guidelines for the humanitarian post-disaster intervention. As shown by Benadusi in the case of Sri Lanka (2015: 93), however, the direct importation of this idea, with no public discussion of its assumptions and aim, has encouraged the proliferation of conflicting interpretations of the slogan.

An analysis of the epistemic, cognitive, normative, financial and judiciary tensions that pervade the process of recovery are at the core of the contributions gathered in this book. The focus is not on developing tools and means for measuring disaster impact and recovery but on providing analytical tools to explore 'the cultural, social-organizational, and politicaleconomic conditions/options that affect how reconstruction occurs (for better or worse)' (Passerini 2000: 71). The matter of whether or not recovery from a disaster is possible, or even desirable, at least for some actors, is also a salient question given serious consideration by the contributors to the volume. The analytical frameworks mobilized are grounded in the assumption that any disaster situation is marked by the uncertainty of the 'what-ness' [START_REF] Quéré | Did you say Pragmatic? Luc Boltanski's Sociology from a Pragmatist Perspective[END_REF] of the disaster, which depends on the diversity of actors experiencing its consequences and their involvement in a variety of processes of acknowledging, evaluating and managing these consequences at different scales. Disasters can be sociologically analyzed as 'problematic situations' in which, following the pragmatist philosopher John Dewey, the usual ways of making sense and doing things do not work. Actors deal with this practical and existential uncertainty by engaging in the contentious process of 'inquiry' in order to cognitively and normatively describe the situation in terms of attributing causes and responsibilities and identifying damages and victims (see [START_REF] Cefaï | Publics, problèmes publics, arènes publiques… Que nous apprend le pragmatisme?[END_REF].

The contributors to this volume share a similar approach in researching processes of recovery that consists in following how the disaster and its consequences are made the object of a variety of sense-making struggles, that is, struggles around the meaning of what happened and how it affected the given order of things and the possible future [START_REF] Centemeri | The Seveso Disaster's legacy[END_REF]2015; see Chateauraynaud and Debaz 2021in this volume). These struggles are interlinked with interest-based struggles and power-based struggles that more often than not reproduce the pre-existing social hierarchy and forms of marginality, as shown by feminist and postcolonial scholars in disaster studies on the Global South (see [START_REF] Fortun | Advocacy after Bhopal: Environmentalism, Disaster, New Global Orders[END_REF][START_REF] Choi | Anticipatory States: Tsunami, War and Insecurity in Sri Lanka[END_REF]. There is evidence, however, that disasters in the Global North also usually intensify pre-existing conditions of inequality in the long term [START_REF] Passerini | Disasters as agents of social change in recovery and reconstruction[END_REF]. We believe that in order to explain the dynamics through which such inequalities are maintained and reinforced, it is crucial to understand how a shared sense of the 'what-ness' of the disaster is generated and stabilized, at least temporarily because we know that this stability is always potentially open to future revision (see Gorostiza and Armiero 2021in this volume).

These sense-making struggles take place in a variety of 'arenas' [START_REF] Cefaï | Qu'est-ce qu'une arène publique? Quelques pistes pour une approche pragmatiste[END_REF]; see also Hiltgarner and Bosk 1988) where the actors concerned come into contact with one another.

An 'arena' can be defined in general terms as a dispositif that brings together speakers and their audiences and that defines a mode of confrontation either between the speakers or between the speakers and their audience [START_REF] Dodier | L'espace public de la recherche médicale[END_REF]. Arenas organize a form of collective reflexivity -and 'reflexivity loops'. They are specialized to varying degrees according to the rules that define the conditions for access [START_REF] Dodier | The force of dispositifs[END_REF]. We can therefore distinguish between technical-expert arenas, judiciary arenas, media arenas, parliamentary arenas and other arenas of public or expert debate. In such arenas, actors express conflicting understandings of the disaster and conflicting normative expectations about what should be done to recover, what is worth recovering and what types of processes can be considered to be a 'good' recovery.

The contributors to this book also examine sense-making struggles in the context of 'governing (by) disasters' dispostifs. As highlighted by Revet and Langumier (2015) in their anthropological approach to dispositifs in disaster situations, 'frictions' [START_REF] Tsing | Friction: An Ethnography of Global Connections[END_REF] are ubiquitous between, on the one hand, the variety of dispositifs that are meant to govern disasters and, on the other, the actors' 'normative expectations' [START_REF] Dodier | The force of dispositifs[END_REF] and the diversity of their practical 'modes of engagement' [START_REF] Thévenot | The plurality of cognitive formats and engagements: Moving between the familiar and the public[END_REF] in the situation. This shows 'the fundamental heterogeneity of the resources that allow individuals and groups to assess risks and position themselves relative to them' (Dodier 2015: 224).

The fact that governing by disasters is now a distinctive feature of contemporary societies should not lead us to assume that the integration of disasters into a 'general economy' is a smooth process (Dodier 2015: 226). If we assume that the power of dispositifs automatically lies in ensuring that the actors' practices and normative expectations align with one another, there is the risk we overlook any frictions or ignore their importance, both in the making and in the unmaking of hegemony (Tsing 2005: 6). Conflicts of interest and power struggles are thus constantly interwoven with processes that aim at defining a shared 'sense of things' across a variety of arenas, dispositifs, scales and temporalities [START_REF] Chateauraynaud | Pragmatique des transformations et sociologie des controverses. Les logiques d'enquête face au temps long des processus[END_REF].

These processes are of crucial importance in explaining the specific observable path to recovery after a disaster, and they cannot be properly understood if the fact that disasters also disrupt everyday life space by affecting people's 'attachments' (in the sense of [START_REF] Hennion | Une sociologie des attachements. D'une sociologie de la culture à une pragmatique de l'amateur[END_REF] is not taken into account.

Direct experiences of death, destruction, toxicity and displacements present the victims of disaster with three vastly different but intertwined needs. They have to find ways of meeting basic physiological requirements, rebuild familiarity with people and places and deal with the irreversibility of loss. Revet and Langumier (2015: 5) noted that:

The everyday life of 'disaster victims' and those 'displaced' by catastrophe cannot be summarized solely in terms of the management of a day-to-day existence that has been impacted by these events. Far from the cameras and in unspectacular fashion, life very quickly resumes its course on the ruins and traces of disaster. […] The issue is therefore no longer to recognize and account for what disaster destroys but what it contributes to producing, the social recompositions it brings about.

From a different perspective but with a similar focus, Aijazi (2015:16) introduced into disaster studies, or more specifically recovery studies, the perspective of social repair developed by Das in her work on and with survivors of violence [START_REF] Das | Life and worlds: violence and the descent into the ordinary[END_REF]). Das' approach reveals that the process of reoccupying the same spaces of daily life that once experienced disruption is peppered with 'acts of self-creation', meaning a renewal and revitalization of oneself, one's social relationships and one's relationship to the place. 'Generative spaces for social remaking' [START_REF] Das | Life and worlds: violence and the descent into the ordinary[END_REF] can thus emerge that are centred on the ordinary activities necessary to keep life going, like providing food and shelter and taking care of children and elderly people.

Initiatives for 'grassroots recovery' can occasionally overlap with 'interstitial initiatives' that aim at reclaiming a form of autonomy from dominant economic and political logics and structures [START_REF] Monticelli | Embodying Alternatives to Capitalism in the 21st Century[END_REF], as in the case of the post-earthquake ecovillage of Pescomaggiore (L'Aquila, Italy) discussed by [START_REF] Tomassi | post-disaster community (2009-2014[END_REF]. 4 However, as shown by [START_REF] Benadusi | The Two-Faced Janus of Disaster Management: Still Vulnerable yet already Resilient[END_REF]2015), grassroots initiatives in contexts heavily exposed to international aid are systematically instrumentalized to support a rhetoric of resilience that reinforces deeply entrenched local power dynamics and the reproduction of conditions of inequality.

The resilience framework and its limitations

Today, 'resilience' is a key concept guiding not only the analysis of but also public interventions in recovery after disaster, and it has generated a vast body of literature (see [START_REF] Alexander | Resilience and disaster risk reduction: An etymological journey[END_REF]. It has prompted researchers to explore the inherent qualities and internal factors that affect a community's ability to recover, or 'bounce back', from disaster and how to translate these factors into quantifiable indicators in order to help design more effective mitigation strategies (amongst such pioneering work, see [START_REF] Mileti | Disasters by Design: A Reassessment of Natural Hazards in the United States[END_REF]. Social capital and a variety of other 'capitals' (including community and economic capitals) and capacities (from improvisation to infrastructure resources) are thus identified as 'elements of resilience' that can be operationalized [START_REF] Kendra | Resilience and disasters[END_REF]. The concept of resilience and its use as a diagnostic and prognostic tool in recovery after disaster is also highly contested (see [START_REF] Aguirre | How not to learn: Resilience in the study of disaster[END_REF][START_REF] Tierney | Resilience and the neoliberal project: Discourses, critiques, practicesand Katrina[END_REF]. In particular, it has met with considerable criticism from researchers attempting to clarify its relationship to the logic of neoliberalism [START_REF] Walker | Genealogies of resilience: from systems ecology to the political economy of crisis adaptation[END_REF][START_REF] Chandler | The Neoliberal Subject: Resilience, Adaptation and Vulnerability[END_REF][START_REF] Revet | Disasterland. An Ethnography of the International Disaster Community[END_REF]. Efforts to operationalize resilience through a list of standardized indicators have to face the fact that responses to disaster are closely connected with socio-historical and cultural dimensions that are specific to each locality and that contribute to shaping the sense of what counts as a 'good' recovery.

Beyond the criticism of the implicit normative assumptions of the resilience metrics that have been developed with the aim of defining a universally valid model of resilience building, resilience has often been 'co-opted' as a justification put forward by neoliberal projects for withdrawing government support for universalistic welfare measures and, more generally, public infrastructure investments. Communities are then forced to compete for public and also increasingly private funding to support resilience building, with the result that: 'Resilience, paradoxically, is not for everyone, but for those who are best equipped to compete in the demanding milieu of government and philanthropic funding mechanisms' (Kendra et al. 2018: 101). On a similar note, Benadusi (2013: 434) highlighted the fact that in post-disaster situations, actors confronted with international aid dispositifs have to appear 'just resilient enough […], but not so resilient as to tarnish the image of vulnerability still required to intercept aid'. In post-Chernobyl Ukraine [START_REF] Petryna | How Did They Survive?[END_REF], post-Fukushima Japan [START_REF] Hasegawa | Disaster Evacuation from Japan's 2011 Tsunami Disaster and the Fukushima Nuclear Accident[END_REF]) and post-Hurricane Katrina New Orleans [START_REF] Adams | Markets of sorrow, labors of faith: New Orleans in the wake of Katrina[END_REF], individuals had to compete in order to 'prove' that their victimized conditions justified state assistance or compensation and that they qualified for it by showing that they were learning to become 'resilient' as a community of (acknowledged) victims. All these cases show how the 'social resilience' framework (see [START_REF] Hall | Social resilience in the Neoliberal Era[END_REF] promotes a specific normativity that is sustained by neoliberal policies and narratives and is based on individual and collective capacities to cope and 'creatively' adapt to unavoidable catastrophes. From this perspective, resilience has been defined as the new 'social morphology' of our societies, which are 'insecure by design' [START_REF] Evans | Resilient life. The art of living dangerously[END_REF].

However, it is important to distinguish between resilience as a governance tool, resilience as a justificatory argument that can be mobilized by a variety of actors in concrete situations and resilience as an analytical framework that can be used to approach the way in which societies respond to disruptions. In this latter case, resilience has the merit of drawing attention to the need for an interdisciplinary approach to the study of recovery after disasters that takes into account the systemic dimension of interwoven ecological, technical, socio-cultural and political factors at different scales. Indeed, the resilience framework invites us to develop an approach to disasters in which social dynamics are analyzed in their interdependences with the specific environment in which the disaster occurs. From the perspective of resilience, disasters can be considered as 'interactive phenomena of social and technical systems distributed over geographic space' (Kendra et al. 2018: 104).

The implicit reference in the resilience framework to the mutually constitutive dynamics of systems and places invites us to include the dimension of milieu (see Chateauraynaud and Debaz 2021 -in this volume) in order to understand how 'nested systems' can produce 'injurious outcomes that cannot be straightforwardly confined in time or space, nor adequately addressed with standard operating procedures and established modes of thought' [START_REF] Fortun | Researching Disaster from an STS perspective[END_REF](Fortun et al. : 1004)). However, we believe that the technocratic reduction of resilience to a tool that can be mobilized by a larger form of neoliberal 'governing through standards' (Ponte et al.

2011

) as well as the community-based focus that this framework implicitly supports and the social morphology it encourages profoundly hinder the potential of such a notion as a tool that can be used to explore the dynamics of post-disaster initiatives and the diversity of patterns towards social change.

The aim of this book is to clear the way for the development of an alternative perspective on researching recovery after disasters that is based on the socially, culturally, politically, ecologically and ethically informed notion of repairing environments. It consists in analyzing how a variety of socio-technical, socio-ecological and socio-cultural repairing issues are defined and dealt with in arenas, 'dispositifs' and practices that together shape the possible paths of recovery after disaster.

From resilience to the multiple meanings of the 'repairing environments' notion

The contributions assembled in this book show how the resilience discourse is displaced, reshaped, enhanced and challenged by introducing a 'repairing' perspective into researching recovery after disasters.

Before going any further, we need to clear up a possible misunderstanding. At the core of the notion of 'repairing' as discussed in this book is a partial distancing from the common understanding of 'repairing' as restoring a being, object, situation or environment that has been impaired to its original state. Our approach is based on considering 'the repair' as an ambivalent social phenomenon that is both transformative and aimed at maintaining a continuity with the past condition through transformation (see [START_REF] Attia | Open Your Eyes![END_REF]. Therefore, the effects of the repair will manifest in an undetermined way in an unforeseeable future with an unknown spatial scope. From this perspective, 'repair' is a notion that can be useful in exploring human communities' relationships with their environment.

Disasters, in all their different forms, remind us of human interdependences with the material world and societies' dependence on material infrastructures and 'infrastructuring practices' [START_REF] Star | The ethnography of infrastructure[END_REF][START_REF] Bowker | Sorting Things Out: Classification and Its Consequences[END_REF][START_REF] Edwards | Infrastructure and modernity: force, time and social organization in the history of sociotechnical systems[END_REF]. Moreover, major chemical and nuclear disasters have contributed at least since the 1960s to the emergence of a form of environmental reflexivity on the global dimension of the ecological crisis epitomized by the sociological 'risk society' category [START_REF] Lagadec | La Civilisation du risque[END_REF]; Amoore 2013; Amoore and de Goede 2008; Beck 1992) and, more recently, to the notion of 'Anthropocene' [START_REF] Bonneuil | The Shock of the Anthropocene[END_REF][START_REF] Blok | The Anthropocene event in social theory: On ways of problematizing nonhuman materiality differently[END_REF]. This implies that it is increasingly hard to draw a clear lineif indeed this were ever possiblebetween what can be considered a natural environment and what can be considered a socially and culturally shaped environment [START_REF] Latour | We were never Modern[END_REF]. In addition, it has become even more difficult to address issues of social change in isolation from larger processes of ecological and technical transformations.

In contrast to the general propensity to speak in terms of an undifferentiated global environment, disaster situations force us to pay attention to 'the activities, materialities, and concepts through which an environment is performed in always situated and contested ways', which reveal 'an array of environments, themselves heterogeneous and differently organized' [START_REF] Blok | Infrastructuring Environments[END_REF]. In fact, disasters disrupt a variety of ecologies that shape environments, thus triggering a multiplicity of repairing processes that account for the emergence, or not, of new patterns of socio-ecological organization (see also [START_REF] Oliver-Smith | Global Changes and the Definition of Disaster[END_REF].

Consequently, this reference to environments points to the need to address the analysis of disaster recovery through a consideration of the variety of material ecologies that become visible as a result of their misfunctioning and the efforts to repair them (see also [START_REF] Frickel | Mapping Knowledge investments in the aftermath of Hurricane Katrina: a new approach for assessing regulatory agency responses to environmental disaster[END_REF]. With regard to the notion of 'environments', we would like to stress the importance of paying attention in the analysis of disaster recovery, on the one hand, to social phenomena as embedded in socio-ecosystems and, on the other, to their place-based nature as phenomena that are geographically located and shaped in a material 'web of life' that is culturally invested with meaning and value [START_REF] Gieryn | A Space for Place in Sociology[END_REF].

By connecting disasters and environments, the objective of this book is to emphasize that disasters potentially reconfigure not only societies but also ontologies through the variety of processes of repairing that actors engage in to return to normalcy. Recent developments in the field of environmental law, like the creation of legal rights for rivers (O'Donnel and Talbot-Jones 2018), point to evolutions in this direction. Furthermore, while the notion of recovery (both in its institutional and scientific conceptualizations) implicitly focuses on the physical-material dimension of disrupted environments at that present time and optimistically assumes that these environments can be restored (or at least recovered or made invisible), the repair perspective takes into account the causes of the disruption, those responsible for it and those suffering from or victimized by it.

It thus takes seriously both the past and the present in its approach to (build) the future.

Finally, it is our understanding that the notion of 'repair' points, much more so than the notion of 'recovery', to a process rather than a finality, which means that the very possibility that certain disaster situations or conditions are unrepairable (although individuals most often seek to repair themas a preliminary condition for survival) is incorporated in it.

As discussed in the chapters of this volume, observing actual processes of recovery after disaster reveals the coexistence of a 'multiplicity' [START_REF] Law | Complexities: Social Studies of Knowledge Practices[END_REF] of possible understandings of repairing that guide actors' conduct as part of the recovery after a disaster.

Repairing, understood here as asking for reparation, can point to the righting of a wrong, typically through means of making amends to those who have been wronged. Thus, the juridical term 'reparation' performs an 'accusatory function, invoking a kind of repair that entails identifying the actor who caused the damage in question, denouncing the formal injustice of damages suffered and determining corresponding faults, crimes, victims and perpetrators' (Dodier 1995translated from French). In this case, the disaster is framed as a moral or juridical crisis requiring reparation through remuneration or other assistance to the party that has been wronged. This implies resorting to the legal or moral code and to the dispositif of the trial [START_REF] Dodier | The force of dispositifs[END_REF]. Legal procedure is, however, not always well adapted to meeting the objectives implied in resolving moral questions. Feelings of injustice can persist when victims or their representatives contest the appropriateness or adequacy of the form of compensation made. The valuation and evaluation of damages to body, life and environment imply a series of complex and contentious processes that can bring about important transformations in legal systems [START_REF] Fourcade | Cents and sensibility: Economic valuation and the nature of "Nature[END_REF][START_REF] Petryna | How Did They Survive?[END_REF]. Beyond monetary compensation, victims or their representatives can ask for symbolic forms of reparation, such as a request for an apology, especially from state actors [START_REF] Mihai | When the State Says "Sorry": State Apologies as Exemplary Political Judgments[END_REF], the importance of which can vary significantly according to the cultural context.

Depending on the nature of disasters and their destructive potential, these contentious processes can also reveal the power of industrial actors and practices of 'ignorance production' or of strategic (non)production and use of knowledge in the context of the evaluation of damages (Oreskes and Conway 2010;Jobin 2021in this volume). A variety of factors influence these reparation processes and their potential to trigger social change, including the existence of national liability mechanisms, juridical and environmental protection systems and the lobbying capacity of collective mobilizations.

During the recovery process, however, actors have to deal not only with a moral crisis but also with the re-establishment and then improvement of the functionalities of the various infrastructures (including the ecological, economic and technical infrastructures) that the disaster has disrupted. The focus of this functional understanding of repairing is not on the past and the identification of crimes but on the future and the discovery and anticipation of dysfunctions [START_REF] Dodier | Les hommes et les machines. La conscience collective dans les sociétés technicisées[END_REF]. 'To repair' means, in this sense, to fix a systemic breakdown so as to avoid its repetition. In this case too, law and regulations play an important role since they should guarantee, at least formally, the conditions for safety and the prevention of future accidents. This implies the mobilization of specific devices such as technical protocols, 'stress tests', maintenance procedures, preparedness measures (see Keck 2021in this volume), ecological restoration programmes (including revegetation, habitat enhancement, remediation) and insurance or liability systems. Furthermore, such devices are increasingly being conceived and organized at an international level, especially in very high-risk sectors such as the nuclear sector (see Topçu 2021in this volume), where the cross-border nature of radioactive fallout has been a major concern since the Chernobyl accident.

These devices are intended to deal with technical issues, but they have a huge impact on the trajectories of recovery. They can be contested on technical grounds (controversies) as well as on the grounds of the social consequences of their design with regard to exclusion and injustice (conflicts). As Klein's Shock Doctrine reminds us, the repairing of infrastructures can present not only an economic opportunity for interest groups but also a political opportunity to advance an alternative vision of how the society in question should function.

The technical fixing of infrastructures inevitably crosses over with the practices that actors engage in individually and collectively to maintain and repair their own environments, which is understood as the everyday relationships of taking care of people, objects, places and nonhuman beings. The reference here is to the notion of 'repair' as discussed by feminist scholars and activists in relation to the concept of care, which was defined by Fisher and Tronto (1990: 40) as: a species activity that includes everything that we do to maintain, continue, and repair our "world" so that we can live in it as well as possible. That world includes our bodies, our selves, and our environment, all of which we seek to interweave in a complex, life-sustaining web.

As Jackson argued when discussing his 'broken world thinking' perspective: 'Care […] reconnects the necessary work of maintenance with the forms of attachment that so often (but invisibly, at least to analysts) sustain it ' (2014: 232). Haraway (2016: 55) referred instead to 'precarious times' and advocated an intense human-nonhuman interplay to 'renew the biodiverse powers of terra' within the Chthulucene, which is: made up of ongoing multispecies stories and practices of becoming-with in times that remain at stake, in precarious times, in which the world is not finished and the sky has not fallenyet. We are at stake to each other. Unlike the dominant dramas of Anthropocene and Capitalocene discourse, human beings are not the only important actors in the Chthulucene, with all other beings able simply to react. The order is reknitted: human beings are with and of the Earth, and the biotic and abiotic powers of this Earth are the main story.

Repairing can thus also be understood as a focus on individual and collective practices of reflexively maintaining one's own world in material, multispecies, experiential and emotional terms. As an expression of care, repair after disasters involves engaging in maintaining, as far as possible, the ordinary activities and experiences (such as providing food, sleeping, taking care of children and spending time with friends and family) that are necessary to support the texture of everyday life. Disasters reveal the importance of such ordinary practices for the preservation of the 'human life form' [START_REF] Lovell | Face aux désastres. Une conversation à quatre voix sur la folie, le care et les grandes détresses collectives[END_REF]. This sense of repairing thus refers to the embodied and 'emplaced' [START_REF] Pink | From embodiment to emplacement: re-thinking competing bodies, senses and spatialities[END_REF]) experience of the catastrophe and points to forms of self-organization that emerge as part of the response to the disaster and recovery process. These practices respond to the need to recreate, at the levels of meaning, attachments and everyday life, close relationships between human beings, on the one hand, and between human beings, other living beings and places, on the other. These repair practices rely on the mobilization of a form of 'negative capability', which is defined as the ability to maintain the continuity of everyday life in the face of its absence or loss of meaning [START_REF] Lanzara | Capacità negativa: competenza progettuale e modelli di intervento nelle organizzazioni[END_REF]. The scope of such repair practices and their contribution to recovery can be understood only through taking into account the importance of the 'familiar environment' as a space in which individual capacities are rooted [START_REF] Breviglieri | L'espace habité que réclame l'assurance intime de pouvoir: Un essai d'approfondissement sociologique de l'anthropologie capacitaire de Paul Ricoeur[END_REF]. In order to grasp repairing at the level of everyday life, ethnography is therefore a fundamental complement to other methodologies of inquiry.

With this third understanding of repair, our aim is to bring to disaster studies recent developments that have emerged in the field of repair studies (see [START_REF] Graziano | Repair Matters[END_REF].

Repair studies focuses on the activities of 'maintaining the world' as a potential 'site of altering', that is, as a potential site of 'contingent political change without relying upon the myth of ex-nihilo creation' (Graziano and Trogal 2019: 214). Far removed from the idea of re-establishing the status quo, repairing as caring thus refers to the work of maintaining interdependences as a potentially transformative process. Repairing practices can therefore be linked to the construction of a collective demand and can sustain struggles for reparation.

However, analyses of the processes of recovery after major nuclear accidents (like Chernobyl and Fukushima) have revealed the instrumentalization of this kind of ordinary repairing through the resilience narrative in order to mask conditions of irreparability and to prove nuclear risk is socially acceptable, thus contributing to the maintenance of the status quo. As discussed by Ribault (2019: 4) in the case of resilience narratives after the Fukushima catastrophe:

As individuals are called upon to act upon themselves hygienically to measure and mitigate radiation exposure after catastrophic levels of contamination, the proposed responses consist in shifting the target for resilience from biology to individual psychology and to society. Resilience is thus operating as a governing technologymore specifically as a technology of consentthat displaces some problemshere the irreversible biological effects induced by radiation exposureby offering substitute problems such as empowering individual [sic] and rebuilding communities.

In the same way, 'nuclearists' in Chernobyl and Fukushima have been promoting a 'radiological culture' (e.g. the use of a Geiger counter on a daily basis to govern everyday activities in such a way as to reduce exposure to radiation) aimed at turning radioactivity into an 'ordinary' feature of the everyday life experience, de facto producing a form of collective ignorance [START_REF] Topçu | Chernobyl Empowerment? Exporting Participatory Governance to Contaminated Territories[END_REF][START_REF] Kimura | Fukushima ETHOS: Post-Disaster Risk Communication, Affect, and Shifting Risks[END_REF].

In this case, the human capacity for 'maintaining one's own world' is instrumentalized in order to sustain a vision of repairing that is exclusively focused on the recovery of systemic functionalities. This vision of functional repairing imposes a technocratic, non-negotiable reconfiguration of ordinary human-environment interdependences that are oriented towards future technoscientific achievements. As Ribault showed in the case of Fukushima, these achievements can include 'robotic, agronomic […], biological, and medical experiments' as well as 'architectural and urban planning experiments including land deregulation, smart cities, and other smart communities projects' (2019: 6). [START_REF] Ribault | Resilience in Fukushima: Contribution to a Political Economy of Consent[END_REF] notion of the 'incantatory' mechanism that is sustained by resilience narratives contributes, in the case of Fukushima, to silencing present experiences of irreparable lossesincluding the invisibility of remediation workersand to hampering collective efforts to transform these harms into damages in need of reparation.

Repairing environments: the contributions

The volume contains 10 contributions (and a concluding chapter) from scholars of diverse disciplinary backgrounds, including sociology, criminology, anthropology, history and philosophy. The majority of the contributions are based on case studies located in different parts of the world, such as France, Spain, Taiwan, Hong Kong, Brazil and Japan. The contributions are organized into three sections, which focus on (1) the challenges of repairing slow and chronic disasters, (2) an analysis of processes of repairing as an expression of collective efforts to remake liveable worlds and (3) the role of law and judicial processes in repairing environmental harms. Of course, there are common theoretical and analytical concerns running through the three sections, which reflects the integration of these perspectives on recovery from the vantage point of repairing.

Collectively, the contributions seek to enhance our knowledge and understanding of the ways in which the different repair logics interact in dispositifs, practices and arenas, where the interplay of normative expectations around recovery and the struggles over sense-making in relation to disaster situations can be analyzed as part of larger interest-based struggles within a power-laden framework. They also raise relevant issues for critically assessing the heuristic potential of the repairing perspective and address broader theoretical questions, especially concerning the contribution of the social sciences to the analysis of transformative dynamics of complex systems.

The first section opens with Paul Jobin's discussion of the 'economy of compensation' and struggle for reparation in the case of Formosa Plastics in Taiwan. The author explores the reparation issues in the case of chronic pollution caused by the activities of a major petrochemical industry. In particular, Jobin highlights how monetary compensation for the damage is consolidating a kind of local economy that ends up legitimizing polluting activities.

At the same time, his research shows the efforts of the victims, who are gathered together in a class action, to make monetary compensation an opportunity to denounce the polluting practices of industry. These collective mobilization experiences allow the participants to develop forms of agency that are worthy of consideration for their potential to ultimately translate into concrete forms of environmental repair.

In Chapter 2, Sezin Topçu analyzes the strategies, doctrines and tools that nuclear states and agencies have elaborated to deal with post-accident recovery. Focusing on the problem of contaminated land, she explores how plans were made for the land to be managed historically and at an international level and how it was or is effectively managed in regions victimized by the Chernobyl and Fukushima accidents. She analyzes the contexts, policies and discourses that, instead of tackling the contaminated zones as a social and political problem, led to the formulation of the problem in terms of the 'technical' modalities of evacuation. In particular, her contribution sheds light on three managerial strategies of recovery (geological, biological and psycho-social) that conflict with the multiple forms of reparation demanded or trialled by activists and victim groups. This section on slow disasters ends with Daniel Delatin Rodrigues's contribution on attempts to repair the ecological disaster caused by the industrialization of agriculture in the Brazilian region of Pontal do Paranapanema. This disaster resulted from a de facto alliance between local elite landowner groups and global modernization processes. The ecological reparation promoted by an agroecology project, which is a collaboration between the Sem Terra movement and local university technicians and academics, cannot therefore be separated from the larger social goal to propose a model of agricultural organization that is more respectful of social and ecological justice. However, this case study shows the difficulties of implementing such a project when most farmers are still totally dependent on globalized economic circuits.

These conditions appear quite unfavourable in terms of the experiments that are necessary in order to find effective socio-ecological reparative agencements between humans and nonhumans.

Section II begins with Santiago Gorostiza and Marco Armiero's historical investigation of the long term consequences of the catastrophic collapse of the Vega da Tera dam in Spain. At around midnight on 9 January 1959, the Vega de Tera dam broke, releasing approximately 8 million cubic metres of water. It destroyed the Spanish town of Ribadelago and killed 144 people. To this day, it remains the worst dam-related failure in the last two centuries of Spanish history. In the aftermath of the disaster, the efforts of the Francoist dictatorship prioritized anticipating similar disasters and avoiding a repetition rather than identifying who was responsible or repairing the victims. In this context, memory emerged as a strategic tool for the recovery of the survivors' individual and collective agency as part of a wider process to achieve social repair. The authors' analysis of the aftermath of the disaster in the long term reveals that the survivors fought to achieve both a judicial and a narrative reparation, which were intertwined.

The next contribution by Frédéric Keck explores a topic of growing centrality in a context of increasingly globalized disasters, which is the processes of repairing following a pandemic.

Focusing on pandemic preparedness in Hong Kong in the aftermath of the 1997 bird flu outbreak, Keck shows that this influenza pandemic was an event that Hong Kong had been preparing for through sentinels, simulation and stockpiling but that it was also a disaster that had already happened in the mass culling of poultry to eradicate the reservoir of the disease.

He explores the disjunction between a disaster that actually affected this bird species and a disaster that could have potentially affected the human species by describing how the mass death of poultry in Hong Kong was perceived as a signal of human extinction. This multispecies approach questions the nature of a community that recovers from a disaster. In particular, Keck discusses how the decision to cull or cure the birds can be understood as a signal of what could happen to humans. He examines the grounds for justifying this decision by looking at the fabric of memory and heritage in the narrative of a collective disaster as a traumatic event.

Following on from this multispecies questioning, Line Marie Thorsen discusses how groups of artists in Japan have been turning towards natural farming and permaculture practices as a way of grappling with environmental and ecological issues after the triple disaster of 3.11, that is the earthquake, tsunami and Fukushima Daiichi nuclear powerplant meltdown of 11 March 2011. The author argues that agricultural artists have a particular potential for reworking aesthetic imaginaries both of life after and of life combatting complex disastrous events through reworking and mending the soil to farm without the use of risky energy forms.

The section ends with Francis Chateauraynaud and Josquin Debaz's contribution on the consequences of the Mariana dam disaster, also known as the Samarco dam disaster. It occurred on 5 November 2015, when a tailings dam at the iron ore mine in the Samarco Mariana mining complex near Mariana, in the Brazilian state of Minas Gerais, suffered a catastrophic failure. Adopting a pragmatist approach to study the long-running critical processes in relation to the Mariana catastrophe, the authors examine how different actors evaluated the multiple ecological, health and socio-economic consequences of the disaster and how they engaged in a variety of processes of reparation. These processes tackled a wide range of conflicting issues related to extractivism and environmental justice, including scientific controversies around the extension of the damage to the coral reef of the Abrolhos Islands. This contribution aims at exploring how actors deal with the question of the (ir)reversibility of damage, how they identify, represent and argue for the possibility, or impossibility, of repairing, restoring and compensating and how these processes shape the dynamics of reconstructing liveable worlds.

The final section on the role of law in repairing environmental harms begins with Lorenzo Natali and Matthew Hall's contribution on green criminology and the case for environmental restorative justice. The chapter approaches the notion of repairing from the manifold perspective of green criminology, presenting some of the theoretical frameworks that appear best suited to support the interdisciplinary debate on recovery after disaster and highlighting the importance of paying attention to the perspectives of human and non-human victims. The authors make the case for restorative justice and mediation-based approaches as a means to provide alternative or parallel justice mechanisms for victims of environmental crimes and harms. In so doing, they highlight innovative directions for future research that might contribute to collectively devise new ways of repairing environmental harm.

In Chapter 9, Sandrine Revet explores, from an anthropological perspective, the possibilities and limitations of a specific judicial dispositif as a way to repair that goes beyond the accusatory understanding of reparation. In particular, she analyzes a specific event in the criminal trials that took place after Storm Xynthia, which caused 29 deaths and extensive destruction in the French municipality of La Faute-sur-Mer in 2010. During the first trial, the court transported the proceedings to the scene of the disaster and organized a walk through the site that had been destroyed by the flood. Based on an ethnographic observation, Revet analyzes the walk not just as a judicial tool of reenactment but also as a means to commemorate the disaster and as a ritual of making amends. She suggests that the notion of reparation in a criminal trial can encompass other dimensions than a mere accusatory one, depending on how the participants make use of the judicial dispositif.

The section ends with Janine Barbot and Nicolas Dodier's contribution, which introduces the notion of the 'ecology of reparation dispositifs' to address the reparation of a health catastrophe. The authors define as 'normative work' the evaluations victims have to carry out with regard to both legal dispositifs (civil or criminal) and other reparation dispositifs (associative, compensatory, medical, media-based, etc.) that contribute to the local ecology of repairing in each disaster. Through the conflicting evaluations that this normative work reveals, victims explicitly show what they value in one judicial strategy over another. These explanations make it possible for the victims to reconstruct their experiences of the different procedures and to analyze how the judicial reparation processes bring them together or divide them and how the strategies they implement fit more broadly into the ecology of the reparation dispositifs that they face. By comparing the ways in which different countries dealt with the same disaster (the growth hormone health disaster), the authors suggest the existence of contrasting national reparation trajectories in relation to the existing ecologies of dispositifs. This contribution extends the approach proposed in the book to the case of health disasters by showing its heuristic potential beyond the analysis of environmental damage that is at the heart of the other chapters. Through the notion of ecologies of dispositifs, the authors also identify a promising path for the development of systematic diachronic and synchronic comparative analyses of recovery trajectories.

In the concluding chapter, we enrich the discussion on the repair perspective, between theory and practice, insisting on the importance of taking into account a plurality not only of normative expectations but also of forms of knowledge and mechanisms of exclusion. In addition, we emphasize the need to highlight the systemic causes of disasters while paying attention to the experience of actors directly affected and their struggles to turn recovery into a process of designing liveable worlds.

If we acknowledge that our book does not outline a 'theory of recovery', we think however that it provides a theoretically informed approach to the study of socio-ecological change that takes into account the interaction between the socio-technical, environmental and cultural dimensions. Finally, as the contributions show, the standpoint of repair adopted in this volume is less normative-laden and politically connoted than resilience and more alert to the contentious nature of recovery processes. Our hope is that in articulating a research agenda centred on the notion of repair, this book will contribute to what [START_REF] Fortun | Researching Disaster from an STS perspective[END_REF]Fortun et al. ( : 1018) ) hoped would progressively become a shared objective in the community of disaster research, namely the development of 'methodologically and theoretically inventive, empirically rich' ways to study disasters that pay attention 'to the acute problems of representations that beset disaster (and disaster studies)'.

A research field that has recently emerged in disaster studies is that of 'self-recovery', which is meant to provide tools to support the process whereby disaster-affected households repair, build or rebuild their shelters either themselves or with the use of local builders while trying to avoid some of the pitfalls that have emerged in the actual practice of resilience-building initiatives (see[START_REF] Twigg | Selfrecovery from disasters. An interdisciplinary perspective[END_REF].


Despite the importance of Botrytis-induced diseases, little is known about conidia production and dispersal which limits our capacity to develop efficient management practices. Hence, the influence of environmental conditions, growing media and different grapevine host organs (including grape bunch trash and mature berries) on sporulation of 10 B. cinerea strains of different transposon genotypes was studied. Mathematical models were developed to describe i) the effect of T° and RH on production of conidia, including a prediction interval which accounts for strain variability; ii) the length of latent period as a function of the degree-days accumulated after inoculation. Optimal conditions for sporulation were: T° between 15 and 20°C, RH>65.5% and medium water activity aw=0.971. Conidia produced on bunch trash and mature berries were significantly correlated with those on artificial media. The relationship between sporulation intensity at the fruit surface and structural, morphological and biochemical changes during grape berry development after veraison was investigated. Sigmoidal increase in fruit susceptibility was observed. After sporulation, Botrytis conidia are dispersed by air currents, splashing water droplets and by insects. In order to improve monitoring of airborne inoculum as an aid to manage Botrytis diseases, dispersal of airborne conidia and incidence of Botrytis fruit rot were monitored at two raspberry plantings, in sprayed (dispersal) and unsprayed field plots, respectively, during three successive years together with meteorological data. The concentrations of conidia were monitored using a Burkard volumetric sampler and rotating-arms samplers. The number of B. cinerea conidia in air samples was determined with a real-time qPCR assay. Dispersal of airborne conidia was assessed at 0.5, 1.0, 1.5, 2.0, 4, and 8 m from a point source inoculum with samplers placed at 0.45, 0.90, and 1.35 m from the ground. The coefficient of correlation between the volumetric and rotating-arms samplers placed at 45, 90, and 135 cm from the ground was significant; and a diurnal pattern of conidial release was observed.

During the pre-bloom and bloom period, conidia dispersal gradient (log conidia/m 3 vs distance in m) showed significant flattering at a distance of more than 2 m from the inoculum source. However, near or at harvest no significant dispersal gradients were observed. Correlation between fruit rot incidence and weekly mean airborne conidia concentration was significant and positive. The impact of these findings on Botrytis rot epidemiology and aerobiology and potential for weather-, host-and inoculum-based disease risk indicators to improve disease management will be discussed.

1

   Research Development Centre, 430 Gouin Blvd.,

	Québec, Canada, J3B 3E6;
	2 INRA, UMR1065 SAVE "Santé et Agroécologie du VignoblE", ISVV, Université de Bordeaux, CS 20032, 33882
	Villenave d'Ornon Cédèx, France.
	odile.carisseo@.agr.gc.ca


Wei-Dong Sun
email: weidongsun@qdio.ac.cn

Charles H Langmuir
email: langmuir@eps.harvard.edu

Neil M Ribe

Li-Peng Zhang

Sai-Jun Sun

He Li

Cong-Ying Li

Wei-Ming Fan

Paul J Tackley

Patrick Sanan

Plume-ridge interaction induced migration of the Hawaiian-Emperor seamounts

Keywords: Pacific plate, Emperor-Hawaii chain, plume-ridge interaction, geochemistry, numerical modeling

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Main Text

The Emperor-Hawaiian volcanic chain consists of ~130 volcanoes and stretches for more than 6000 km across the Pacific plate. It played a key role in supporting the theory of plate tectonics and the plume hypothesis that suggested the Hawaiian-Emperor chains formed by a moving Pacific plate coupled with a stationary mantle plume [1,2]. The famous bend between the Emperor and the Hawaiian chains has been attributed to a major change in the drifting direction of the Pacific plate [1][2][3][4]. This has been challenged by paleomagnetic results, however, which suggest that the Detroit seamount (76-82 Myr) erupted at a paleolatitude of ~36°N. The surface expression of the plume then moved southward towards the current latitude (19°N) [5,6]. Consequently, it has been proposed that the Emperor Seamount trend formed by the rapid migration of the Hawaiian plume between 81 to 47.5 Myr ago, instead of changes in the direction of the Pacific plate [5], although this conclusion is by no means universally accepted [3,7]. Any explanation for the tracking of the Emperor Seamounts prior to the bend must take into account the clear correlation between distance and age revealed by dating of the volcanoes of the Hawaiian chain. One of the features of this relationship, however, is that between about 80 and 55 Myr, the linear relationship breaks down (Figure 1e) with offsets from the linear trend of as much as 300 km relative to the stationary Louisville seamount chain [8]. The offset has previously been explained by a combination of hotspot and plate motion changes driven by plate/mantle reorganization [8]. Others have proposed that the misfit between different reconstructions related to the Hawaiian-Emperor chains was due to intraplate deformation [9], whereas the paleomagnetic data were partially due to true polar wander [4].

Here we show that the volcanic migration rate of the Emperor seamounts calculated from ages [3] and distance between corresponding seamounts differ from the drifting rate of the Pacific plate obtained through plate reconstruction based on magnetic anomalies using GPlates [10] (Figure 1). This discrepancy seems to require first a northward (Detroit to Suiko) and then a southward (Suiko to Koko) movement of the Hawaiian plume. When these movements are viewed in the context of the changes in the volume of the Emperor Seamount chain with time, and the variations in the geochemistry of the erupted volcanic rocks, they suggest that interaction of the plume with the spreading center that were in the north Pacific at that time may be the cause of the age-distance disparities (Figure 1a-e).

High precision ages together with relative distances for volcanoes of the Emperor Seamount chain can be used to calculate the changes in migration rate between ~ 76 to 50 Myr ago [3]. Based on isotopic dating results [3], the fast migration of the volcanos from Suiko to Nintoku (8.9 ± 1.4 cm/year) and then to Koko (17 ± 5.4 cm/year) occurred between 60.9 ± 0.3 and 52.6 ± 0.8 Myr. In contrast, according to plate reconstruction, the Pacific plate drifted slowly (~ 2.9 to 5.4 cm/year) during this period. This misfit requires rapid southward migration of the surface expression of the hot spot by 670 ± 280 km. In contrast, at older times the migration rate of the Hawaiian plume based on volcano ages is smaller than the drifting rate of the Pacific plate between ~76 and 60.9 Myr, obtained using the same methods, which requires northward migration of the plume by 610 ± 230 km, consistent with the distance of the southward migration within error (Figure 1d).

During these time periods, the volume of the Emperor Seamount chain also changed progressively. This is readily apparent from the map view of the seamount chain (Figure 1c), but surface volumes are quantified in Figure 1a. The volumes are the greatest for the oldest parts of the seamount chain, Detroit and Meiji seamounts. They decrease and then stabilize at about half the maximum volume, until they decrease to low values between Nintoku and Ojin (See the map in Fig. 1c).

These observations then suggest an explanation for the time-distance relationships of the Emperor seamounts that were influenced by plume-ridge interaction. Interactions between spreading ridges and mantle plumes are common in the Earth's history [11][12][13][14][15][16] and have previously been proposed as an explanation for the Hawaii-Emperor bend (7). As shown by numerical modeling (Figure 2 and Supplementary Information), as a spreading ridge moves, the interacting mantle plume may be deflected/carried along for millions of years through entrainment of plume flow by the ridge [17][18][19][20]. The interaction may also change the migration rate of the ridge [11], e.g., leading to ridge jump towards the plume, forming asymmetric sea-floor spreading [21,22]. Jellinek et al point out that plume is attracted towards an approaching ridge and eventually captured by it, leading to a surface manifestation of volcanism that is offset relative to the deep plume stem [23].

Our numerical modeling suggests that as the moving ridge approaches the plume, the plume is attracted towards the ridge, leading to an apparent offset in the plume position (Figure 2). Deeply rooted plume magmas can then be preferentially channeled to and erupted at the ridge-axis with increased melt production. As the ridge subsequently moves away from the plume, the plume is no longer deflected and volcanism moves rapidly back to be positioned over the deeply rooted plume stem (Figure 2).

Schilling identified this tendency long ago by adopting the term "plume source-ridge sink", when he showed that plumes far off-axis could be focusing some of their material to ridges several hundred kilometer distant [24]. Jellinek et al point out that faster spreading ridges can be particularly effective in entraining plume flow [23]. Previous numerical modeling consistently suggests that the plume may be offset by several hundred kilometers [20]. Wessel and Kroenke discussed the potential effects of plume-ridge interaction in the Emperor chain to explain the relative motion of Hawaii and Louisville plumes. They, however, thought "it remains a speculative scenario that is difficult to test" [4]. Our modeling clearly indicates that plume-ridge interaction may plausibly explain the offsets obtained by comparing the migration of the Emperor seamounts and the drifting of the Pacific plate.

These various considerations of volume, geochemistry, observations of plume capture by spreading centers elsewhere and theoretical models raise the possibility that plume-ridge interaction influenced the ancient plume that formed the Emperor Seamounts. At the time of formation of the oldest part of the chain, the Hawaiian plume first encountered the approaching ridge, leading to a slight southward movement of the shallow part of the plume to feed the ridge. This led to increases in volume and a depleted chemical signature of basalts as the ridge approached the plume. As the ridge moved northwards away from the plume, plume flow remained entrained by the ridge, distorting the age-distance relationships. Once the ridge was far enough away, plume flow would become vertical once again, causing a rapid migration of surface volcanism. The rapid migration would lead to low volumes at the surface until the surface volcanism was once again stably aligned over the deep plume center. This would account for the low volumes of the Emperor chain, apparent in the map and volume data, between Nintoku and Ojin seamounts (Figure 1 a-c).

The geochemical signatures of basalts from the Emperor Seamount chain also change systematically with time from depleted (similar to mid-ocean ridge basalt, MORB like) to enriched (ocean island basalt, OIB, affinities) [25,26], with significant correlations between ages (or distance) and isotope and element ratios (Figure 3). For example, the average 87 Sr/ 86 Sr increases from a MORB value of 0.70275 in Detroit volcanic rocks up to an OIB value of 0.70357 in Mauna Kea basalts (Figure 3a). The change in average Nd isotope composition is less striking. It drops from 143 Nd/ 144 Nd = 0.51312 (in the range of MORB values) to 143 Nd/ 144 Nd = 0.513029 in Ojin basalts (similar to those of Mauna Kea) (Figure 3b). The average 3 He/ 4 He ratio increases with decreasing ages, from 10.6 ± 1.95 (close to MORB values) in Detroit volcano to typical OIB values of 21.35 ± 1.90 in Koko samples (Figure 3c) [26]. Trace element ratios sensitive to MORB and OIB components also correlate with age. The average La/Yb ratios increase from MORB values of 0.96 ± 0.01 in Detroit volcano to typical OIB values of 13.75 ± 9.16 in Koko samples (Figure 3d). The average Zr/Y ratios increase from 2.49 ± 0.03 in Detroit to 9.66 ± 2.61 in Koko (Figure 3e). These geochemical characteristics can be plausibly explained by mixing of enriched and depleted components (Supplementary Figure S6 and Dataset S2).

The MORB affinities of the Emperor volcanos increased from Meiji at ~ 85 Myr and peaked at Detroit at 76-82 Myr and then declined continuously (Figure 3). The MORB affinities of the Meiji basalt suggest the commencement of the ridge-plume interaction with southward migration at ~85 Myr, which may also have been responsible for the gap between Bowers and Shirshov Ridges. In addition, the Meiji and Detroit seamounts are similar to oceanic plateaus in size, much larger than other Emperor Seamounts. There is also a relationship between the estimated volumes of the individual Emperor Seamounts and the proportions of depleted components in the sampled basalts (Figure 3f). Plume magmas form through decompression partial melting of hot mantle materials. The thickness of oceanic lithosphere decreases towards the spreading ridge. When a plume is beneath the ridge, the upwelling distance of plume materials is considerably increased, and the plume is diluted by normal asthenospheric mantle, as well as undergoing larger degrees of partial melting.

Consequently, in addition to enriched components (OIB affinities), depleted (MORB-like) components that are refractory under normal oceanic lithosphere, are also melted [25].

Viewed from this perspective, both the volume and geochemical data suggest that the ancient Hawaiian plume was interacting with a spreading center. At ~85 Myr, the plume was attracted southward to a spreading center (to 19° N, Supplementary Figure S7), leading to large eruptive volumes and more depleted compositions. This is consistent with plate reconstructions using GPlates and previous results [4,11,[START_REF] Steinberger | Plate-tectonic reconstructions predict part of the hawaiian hotspot track to be preserved in the bering sea[END_REF], which suggest that the Hawaiian plume was near the northern Pacific spreading centers at ~85 Myr.

The Detroit volcano has ages ranging from 82-76 Myr, with large fluctuations in paleolatitude (~26-40°N) [5]. This cannot be explained by migration of the plume, because Meiji is right next to Detroit. Note, Meiji was erupted at ~19°N 82-85 Myr ago, the same as current Hawaii (Supplementary Figure S7) [START_REF] Marshall | The magnetic properties of some dsdp basalts from the north pacific and inferences for pacific plate tectonics[END_REF], which is consistent with the stationary mantle plume model [2].

Our results show that the upper part of the Hawaiian plume was carried northward between Detroit and Suiko, with an offset of ~ 600 km (Figure 1d and2). This can plausibly explain the paleolatitudes of Detroit within error. In addition, there might be a true polar wander during this period [4].

In this case Meiji seamounts were erupted when the plume was drawn southward into the ridge. The southward movement of the plume may have started at the Bowers Ridges in the Bering Sea [START_REF] Steinberger | Plate-tectonic reconstructions predict part of the hawaiian hotspot track to be preserved in the bering sea[END_REF], which explains the gap between the Bowers and the Shirshov Ridges. As the spreading ridge moved to the north, plume volcanism was shifted towards it, forming Detroit, Suiko etc. As the ridge moved further, it lost contact with the Hawaiian plume, leading to the exceptionally rapid southern migration as plume magmatism returned to the top of the plume stem (Figure 4). Ridge-plume interaction at Detroit has long been identified by geochemists [25]. Previous studies have proposed that the Hawaiian plume may have been captured by a moving ridge [6].

However, the authors then argued that the plume was further carried by sub-Pacific mantle flow [6], and that "the Hawaiian-Emperor chain bend morphology was caused by hotspot motion, not plate motion" [START_REF] Bono | Hotspot motion caused the hawaiian-emperor bend and llsvps are not fixed[END_REF]. The plume-mantle interaction model was taken as "a speculative scenario that is difficult to test" [4].

Such ridge-plume interactions are supported by plate reconstructions. The spreading ridge between the Izanagi and the Pacific plates moved northward at least since 125 Ma and passed over the Hawaiian plume. Plate reconstruction shows that the Hawaiian plume may have started to interact with the Pacific-Izanagi spreading ridge at ~ 90 Myr ago [11]. Our results suggest that the stem of the Hawaiian plume likely had a stable location from 47.5 to 85 Myr. The discrepancies with the linear age-distance trends were caused by the interaction of the plume with the spreading ridge during this period. This would resolve the problem of very fast migration rates, and the discrepancies between the Hawaiian and Louisville hot spot tracks, and account for the marked changes in eruption volumes and chemical compositions during this time period. Emperor seamounts. Note there is no seamount between Nintoku and Ojin. Base map is from NOAA (https://www.ngdc.noaa.gov/). d, The northward migration rate of the Emperor seamounts based on high precision ages [3] and the northward migration rate of the Pacific plate calculated from plate reconstruction using GPlates [10] (averaged between seamounts). The different migration rates suggest that the Hawaiian plume moved northward relative to the mantle framework before ~ 61 Myr (Suiko), and then changed to southward absolute motions. e, Age-distance diagram modified after reference [8], showing two major offsets, which corresponds to a northward migration near Detroit seamount and a rapid southward migration between Nintoku and Ojin. All these support plume-ride interaction: the plume was captured by a northward migrating ridge and migrated northward; it then migrated southward rapidly once the ridge lost control on the plume. Note:The 40 Ar/ 39 Ar age is measured using step heating technique.

Numerical modeling

Plume-ridge interaction numerical modeling is conducted using the code StagYY (11). This code employs a finite-volume multigrid method to solve for inertia-free flow in a fluid with variable viscosity.

The model domain is a rectangular box 400 km deep (the z-direction), 2400 km long (the x-direction), and 800 km wide (the y-direction). It is divided into 288 × 96 × 48 elementary volumes with horizontal dimensions dx = dy = 8.33 km and variable vertical dimension (the grid is refined near the top of the box).

FiguresFigure 1 .

 1 Figures

Figure 2 .

 2 Figure 2. Typical evolution of plume-ridge interaction predicted by the numerical model. The plume has radius a = 55 km and excess temperature ∆T = 250 K, and the half-spreading rate and migration rate of the ridge are U = Um = 3.2 cm/yr. The mantle plume is attracted towards the ridge at a distance of ~ 580 kilometers, and then carried by the moving ridge. The melting is intensified dramatically during this process. The ridge lost control on the plume when it is ~ 620 kilometers away from the original position of the plume stem. Please refer to the Supplementary materials for more detailed information.

Figure 3 .

 3 Figure 3. Changes of the geochemical characteristics of basalts from the Hawaiian-Emperor chain with age. a. 87 Sr/ 86 Sr; b. 143 Nd/ 144 Nd; c. 3 He/ 4 He; d. La/Yb; e. Zr/Y. f. The volumes of the Emperor Seamounts are positively correlated with proportions of MORB components. The volumes of Meiji and Detroit are very large, comparable to oceanic plateaus with large proportions of MORB components, supporting plume-ridge interactions. The declining MORB components southward may best be explained by the southward migration of the Hawaiian plume and increasing age (and thus thickness) of the oceanic crust. Data are listed in the Supplementary materials.

Figure 4 .

 4 Figure 4. a-f. Cartoon showing ridge-plume interactions when the northward migrating spreading ridge passed the originally stationary Hawaiian mantle plume. a. The Hawaiian plume was originally located to the north of the spreading ridge between Pacific and Izanagi plates. b. Plume is attracted southward, intensified with increasing proportion of MORB component as the spreading ridge approaches (Meiji), because of decreasing thickness of the overriding plate. c, d.Plume is channeled to the ridge, and is further intensified, with more MORB component as the ridge moves further north, carrying the plume with it. Meanwhile migration of the ridge is probably slowed down due to plume-ridge interaction. e. As the ridge moves further to the north, it lost

Acknowledgments

This study was supported by MOST of China 2016YFC0600408, CAS XDB18020000, to W.D.S. N.M.R. acknowledges support from grant BFC 221950 from the Progamme National de Planétologie (PNP) of the Institut des Sciences de l'Univers (INSU) of the CNRS. We thank Professor A.W. Hofmann for constructive discussions. W.D.S. initiated the study, conceived and drafted the manuscript. L.P.Z. carried plate reconstruction using GPlates and plotted related figures. C.H.L. provided key points and suggestions on the chemical characteristics and volume of the seamounts that dramatically improved the manuscript. N.M.R. did the numerical modeling. S.J.S. plotted the geochemical figures. P.J.T. and P. S. wrote and maintained the code StagYY. W.D.S. and C.H.L. finalized the manuscript with input from all authors.

Conflict of Interest

The authors declare no competing interests.

Author Contributions

SUPPLEMENTARY INFORMATION

Plume-ridge interaction induced migration of the Hawaiian-Emperor plume

Wei-dong Sun 1-3 *, Charles H. Langmuir 4 *, Neil M. Ribe 5 , Li-peng Zhang 1,3 , Sai-jun Sun 1,3 , He Li 1,2 , Cong-ying Li 1,2 , Wei-ming Fan 3,6 , Paul J. Tackley 7 and Patrick Sanan 7 1 Center of Deep Sea Research, Center of Ocean Mega Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China 2 Laboratory for Marine Mineral Resources, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China 3 University of the Chinese Academy of Sciences, Beijing 100049, China 4 Department of Earth and Planetary Sciences, Harvard University, Cambridge, USA. 5 Univ Paris 11, CNRS, Lab FAST, F-91405 Orsay, France 6 Email: weidongsun@qdio.ac.cn; langmuir@eps.harvard.edu

This PDF file includes:

Supplementary text

SUPPLEMENTARY INFORMATION

Volume calculation

The volumes of the Emperor seamounts have been calculated in two different ways using ArcGIS: First, along track volume of every 0.5 degrees; Second, volumes of individual seamounts.

ArcGIS is a GIS (Geographic Information System) software, developed by ESRI (Environmental Systems Research Institute, US). It has powerful spatial analysis ability.

We use the 3D Analyst module in Arc Toolbox to calculate volume based on bathymetry data. Bathymetry data, a 15 arc-second grid, is from the General Bathymetric Chart of the Oceans, GEBCO (https://www.gebco.net/), which is the latest global bathymetric product. First, we define the projected coordinate system of the bathymetric data as

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Robinson. Then, each slice or seamount is clipped out from the projected bathymetry data using Raster Processing module in Arc Toolbox. Each slice or seamount chooses an altitude as the reference plane based on the height variations of seabed around the slice or seamount, and the volume above the plane is calculated. For the along track volume calculation, the seamount chain was first sliced every 0.5 degrees (Figure S2).

The volume of each slice has been calculated, and the result is listed in Table S1. The Hawaiian-Emperor seamounts are either as isolated or as clustered volcanic shields. We divided the chain into individual seamounts based upon the change of the seamount elevation and the relationship with adjacent seamounts (Figure S3). The volume has been calculated for each seamount. In this study, we mainly focus on the volume of eight seamounts, namely Meiji, Detroit, Suiko, Ojin, Koko, Kimmei, Yuryaku and Daikakuji, the calculated results are summarized in Table S2.

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Table S1 Along Emperor track volumes from Meiji for every 0.5 degrees where D/Dt is the convective time derivative that follows the motion of a material particle. The units of Γ are s -1 , or m 3 of melt per m 3 of source material per second.

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Finally, the total rate of melt production beneath a point (x, y) at the surface z = 0 is

where d = 400 km. The 'max' in the integrand means that q accounts only for melting (Γ > 0), and does not include any negative contributions due to freezing (Γ < 0). This is because melt is assumed to be extracted before it refreezes. The quantity q(x, y) is equal to the flux of melt at (x, y) only if all melt is extracted vertically, which is not in general the case. However, the spatial resolution of our large-scale numerical models is not adequate for calculating reliable melt trajectories. We therefore use q as a measure of the amount of melt produced beneath a given point.

To define a reference plume-ridge interaction model we use a number of geophysical constraints. First, the rates of northward drift of the Pacific and Izanagi plates at the time of interaction of the ridge with the plume were ≈ 10 cm/yr and 20 cm/yr, respectively (13). Those values imply U = 5 cm/yr and Um = 15 cm/yr. Second, the duration of eruption of the ridge-influenced seamounts Detroit and Meiji was ≈ 9 Ma

(1-4). Third, the length of the Meiji volcanic edifice along the ridge was ≈ 300 km.

Finally, the total volume of Detroit and Meiji before erosion was ≈ 6.5 × 10 5 km 3 .

To satisfy the constraint on the volume of Detroit and Meiji, we adjusted the strength of the plume by varying its radius a while the excess temperature T = 225 K was held fixed. The volumetric melt flux to the ridge at each time step was calculated by collecting the melt formed within 50 km to either side of the ridge and over an alongstrike distance of 300 km. The total volume of erupted melt was then calculated by

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integrating the volumetric flux with respect to time over 9 Ma starting when plumeridge interaction was just beginning (between the times of Figure S4a andS4b). The iterative process just described yields a = 62 km for a total melt volume 6.7 × 10 5 km 3 .

The buoyancy flux of the plume varies by about 33% as the ridge moves over it, but the maximum value is 1500 kg/s. This can be compared with the estimate of ≈ 2800 kg/s for the present-day Hawaiian plume (14).

It is also possible to estimate how much of the total melt flux q is derived from the plume source as opposed to the MORB source. To do this, we assumed that melting occurring at a temperature T > 1.01T0 1616 K involves the plume source, whereas melting at lower temperatures involves the MORB source. We then used (Ⅶ) to calculate separately the flux q1 from the plume source and the flux q2 from the MORB source.

Two-component mixing

The two-component mixing model is widely used in geochemistry. The mixing can be described using the following Equation: