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133 results on '"Raphaël Paris"'

1. Exploring the links between volcano flank collapse and the magmatic evolution of an ocean island volcano: Fogo, Cape Verde

Author

Mélodie-Neige Cornu, Raphaël Paris, Régis Doucelance, Patrick Bachélery, Chantal Bosq, Delphine Auclair, Mhammed Benbakkar, Abdel-Mouhcine Gannoun, and Hervé Guillou

Subjects
Medicine, Science
Abstract

Abstract Mass-wasting of ocean island volcanoes is a well-documented phenomenon. Massive flank collapses may imply tens to hundreds of km3 and generate mega-tsunamis. However, the causal links between this large-scale, low-frequency instability, and the time–space evolution of magma storage, crystal fractionation/accumulation, lithospheric assimilation, and partial melting remains unclear. This paper aims at tracking time variations and links between lithospheric, crustal and surface processes before and after a major flank collapse (Monte Amarelo collapse ca. 70 ka) of Fogo volcano, Cape Verde Islands, by analysing the chemical composition (major, trace elements, and Sr–Nd–Pb isotopes) and age-controlled stratigraphy (K–Ar and Ar–Ar dating) of lavas along vertical sections (Bordeira caldera walls). The high-resolution sampling allows detecting original variations of composition at different time-scales: (1) a 60 kyrs-long period of increase of magma differentiation before the collapse; (2) a 10 kyrs-long episode of reorganization of magma storage and evacuation of residual magmas (enriched in incompatible elements) after the collapse; and (3) a delayed impact at the lithospheric scale ~ 50 kyrs after the collapse (increasing EM1-like materiel assimilation).

Published
2021
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2. SO2 and tephra emissions during the December 22, 2018 Anak Krakatau eruption

Author

Mathieu Gouhier and Raphaël Paris

Subjects
SO2 degassing, Volcanic ash, Flank Collapse, Anak Krakatau, Geology, QE1-996.5
Abstract

On December 22, 2018 the south-western flank of Anak Krakatau collapsed into the sea, removing 93.8 × 106 m3 of subaerial lavas, and generated a tsunami. Synchronously with the collapse, a large volcanic plume of SO2 and ash (14–15 km in height) has formed, marking the onset of a paroxysmal eruption lasting from December 22, 2018 to January 06, 2019. From remote sensing analysis, we show that the eruption can be divided into three main phases. Phase I and II show both tephra and gas emissions while phase III is mostly degassing. The total amount of SO2 injected in the atmosphere is 173±52 kt, while the minimum bulk magma volume emplaced, estimated from a topographic reconstruction, is ∼45 × 106 m3. This value compares well with a petrologic-based estimate of 56.4 × 106 m3, making the existence of external sulphur sources and sinks quite unlikely. The ice-rich ash plume formation shows that a strong sea-water/magma interaction was responsible for the phreatomagmatic activity throughout the eruption. However, we distinguish a first Vulcanian blast-derived eruption (lasting 40 min) just after the collapse having a Mass Eruption Rate (MER) of 9 × 105 kgs−1, followed by a sustained lower-intensity eruption resulting in ash emissions over hours (MER = 5 × 105 kgs−1). From December 23, daytime photos show typical Surtseyan activity.

Published
2019
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3. Probabilistic Tsunami Hazard and Risk Analysis: A Review of Research Gaps

Author

Jörn Behrens, Finn Løvholt, Fatemeh Jalayer, Stefano Lorito, Mario A. Salgado-Gálvez, Mathilde Sørensen, Stephane Abadie, Ignacio Aguirre-Ayerbe, Iñigo Aniel-Quiroga, Andrey Babeyko, Marco Baiguera, Roberto Basili, Stefano Belliazzi, Anita Grezio, Kendra Johnson, Shane Murphy, Raphaël Paris, Irina Rafliana, Raffaele De Risi, Tiziana Rossetto, Jacopo Selva, Matteo Taroni, Marta Del Zoppo, Alberto Armigliato, Vladimír Bureš, Pavel Cech, Claudia Cecioni, Paul Christodoulides, Gareth Davies, Frédéric Dias, Hafize Başak Bayraktar, Mauricio González, Maria Gritsevich, Serge Guillas, Carl Bonnevie Harbitz, Utku Kânoǧlu, Jorge Macías, Gerassimos A. Papadopoulos, Jascha Polet, Fabrizio Romano, Amos Salamon, Antonio Scala, Mislav Stepinac, David R. Tappin, Hong Kie Thio, Roberto Tonini, Ioanna Triantafyllou, Thomas Ulrich, Elisa Varini, Manuela Volpe, and Eduardo Vyhmeister

Subjects
tsunami, probabilistic method, hazard, risk, research gap, Science
Abstract

Tsunamis are unpredictable and infrequent but potentially large impact natural disasters. To prepare, mitigate and prevent losses from tsunamis, probabilistic hazard and risk analysis methods have been developed and have proved useful. However, large gaps and uncertainties still exist and many steps in the assessment methods lack information, theoretical foundation, or commonly accepted methods. Moreover, applied methods have very different levels of maturity, from already advanced probabilistic tsunami hazard analysis for earthquake sources, to less mature probabilistic risk analysis. In this review we give an overview of the current state of probabilistic tsunami hazard and risk analysis. Identifying research gaps, we offer suggestions for future research directions. An extensive literature list allows for branching into diverse aspects of this scientific approach.

Published
2021
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4. Systematic Review Shows That Work Done by Storm Waves Can Be Misinterpreted as Tsunami-Related Because Commonly Used Hydrodynamic Equations Are Flawed

Author

Rónadh Cox, Fabrice Ardhuin, Frédéric Dias, Ronan Autret, Nicole Beisiegel, Claire S. Earlie, James G. Herterich, Andrew Kennedy, Raphaël Paris, Alison Raby, Pál Schmitt, and Robert Weiss

Subjects
coastal boulder deposits, storm waves, tsunami, hydrodynamic equations, coastal erosion, coastal hazard, Science, General. Including nature conservation, geographical distribution, QH1-199.5
Abstract

Coastal boulder deposits (CBD), transported by waves at elevations above sea level and substantial distances inland, are markers for marine incursions. Whether they are tsunami or storm deposits can be difficult to determine, but this is of critical importance because of the role that CBD play in coastal hazard analysis. Equations from seminal work by Nott (1997), here referred to as the Nott Approach, are commonly employed to calculate nominal wave heights from boulder masses as a means to discriminate between emplacement mechanisms. Systematic review shows that this approach is based on assumptions that are not securely founded and that direct relationships cannot be established between boulder measurements and wave heights. A test using an unprecedented dataset of boulders moved by storm waves (with associated sea-state data) shows a lack of agreement between calculations and actual wave heights. The equations return unrealistically large heights, many of which greatly exceed sea states occurring during the boulder-moving storms. This underscores the finding that Nott-Approach wave-height calculations are unreliable. The result is general, because although the field data come from one region (the Aran Islands, Ireland), they represent a wide range of boulder masses and topographic settings and present a valid test of hydrodynamic equations. This analysis demonstrates that Nott Approach equations are incapable of distinguishing storm waves from tsunami transport and that wave heights hindcast from boulder masses are not meaningful. Current hydrodynamic understanding does not permit reliable computation of wave height from boulder measurements. A combination of field, numerical, and experimental approaches is required to quantify relationships between wave power and mass transport onshore. Many CBD interpreted as tsunami deposits based on Nott-Approach analysis may in fact have been emplaced during storms and should therefore be re-evaluated. This is especially important for CBD that have been incorporated into long-term coastal risk assessments, which are compromised if the CBD are misinterpreted. CBD dynamics can be better determined from a combination of detailed field measurements, modeling, and experiments. A clearer understanding of emplacement mechanisms will result in more reliable hazard analysis.

Published
2020
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5. Explosive eruption, flank collapse and megatsunami at Tenerife ca. 170 ka

Author

Raphaël Paris, Juan J. Coello Bravo, María E. Martín González, Karim Kelfoun, and François Nauret

Subjects
Science
Abstract

Oceanic shield volcanoes flank failures can generate large tsunamis. Here, the authors provide evidence that two tsunamis impacted the coast of Tenerife 170 Ma, the first generated by volcano flank failure and the second following a debris avalanche of the edifice during an on-going ignimbrite-forming eruption.

Published
2017
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7. Job retention for people with bipolar disorder: A qualitative analysis

Author

Elise Marion‐Paris, Emma Beetlestone, Raphaël Paris, Mouloud Bouhadfane, Antoine Villa, and Marie‐Pascale Lehucher‐Michel

Subjects
Arts and Humanities (miscellaneous), Developmental and Educational Psychology, General Medicine, General Psychology
Abstract

At least half of people with bipolar disorder, whose global prevalence is greater than 1% of the general population, do not have a stable occupation. The objective of this study is to identify the factors perceived by bipolar people as having an impact on retention in employment. Semi-directed individual interviews were offered to subjects with bipolar disorder, of working age, who had been seen by three different hospital departments in the south of France. These people had to be medically stable and have at least one occupational experience. Each interview was recorded and transcribed manually and then analyzed according to a thematic classification of verbatims. Nineteen people participated in the interviews. Three major themes identified were classified into intrinsic (working routine and working environment) and extrinsic (external aids) factors for the bipolar person. The majority believe that working regular hours is a balancing factor. For everyone, night work and stress factors can lead to relapses. All stressed the need to destigmatize the disease. Most believe that it is necessary to develop employment support organizations specific to mental illnesses. This research helps to inform people with bipolar disorder about the occupational factors that help balance their condition. Personalized multidisciplinary care pathways involving occupational medicine must be developed in order to promote the balance of the disease and job retention.

Published
2022

9. L'éruption du volcan Hunga Tonga -Hunga Ha'apai le 15 janvier 2022 : un ébranlement du système Terre à l'échelle planétaire

Author

Christine Lac, Alexis Le Pichon, Constantino Listowski, Ghislaine Abbassi, elvyra Astafyeva, alexandre baron, Daniel Berveiller, Marie Boichu, Cathy Clerbaux, Augustin Colette, Gaelle collin, P. Coïsson, Alain Dabas, Gérald Dibarboure, Valentin Duflot, Aurelien Dupont, Thomas Farges, Yannice Faugère, Jean-François Faure, Artem Feofilov, Audrey Gailler, Raphaël Grandin, Vincent Guidard, Alain Hauchecorne, Hélène Hebert, Philippe Heinrich, Philippe Hereil, Albert Hertzog, Sergey Khaykin, Philippe Keckhut, Philippe Labazuy, Sébastien Lafont, Nicolas Lardjane, Bernard Legras, Benjamin Loubet, Boris Maletckii, Marc Mandement, Fabio Manta, caroline mercier, Edhah Munaibari, Raphaël Paris, sébastien payan, Guillaume Payen, Aurélien Podglajen, Anne Puissant, Mathieu Ratynski, Michela Ravanelli, Marina Ripon, Jean Roger, Lucie Rolland, Pasquale Selitto, Anthony Sladen, Cedric Twardzik, Vincent Rey, and Julien Vergoz

Subjects
géophysique, volcan, ondes, observations satellitaires, tsunami, composition atmosphérique
Abstract

L'éruption explosive du volcan Hunga Tonga - Hunga Ha’apai (HTHH), le 15 janvier 2022, a produit la plus puissante explosion enregistrée depuis les explosions du Krakatau et du Tambora dans les années 1800, libérant une énergie équivalente à 110 mégatonnes de TNT. Les ondes générées se sont propagées dans le sol, et dans l’atmosphère jusqu’à l’ionosphère. L'onde atmosphérique la plus énergétique observée sur les baromètres correspond au mode de Lamb. De période supérieure à 2000 s, son amplitude est comparable à celle observée lors de l’éruption du Krakatau en 1883. L’empreinte des perturbations atmosphériques a été caractérisée à l’échelle planétaire par des réseaux de mesures au sol, à bord de satellites ou de plateformes aéroportées. L’analyse combinée de ces observations a permis d’évaluer les conséquences à court terme de l'éruption du HTHH. Les méthodes d'investigation géophysiques présentées dans cette note montrent l’apport d’analyses interdisciplinaires pour caractériser la réponse impulsionnelle des enveloppes fluides planétaires (atmosphère, océans et mers) à une éruption d’une intensité exceptionnelle.

Published
2022
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10. Towards the new Thematic Core Service Tsunami within the EPOS Research Infrastructure

Author

Andrey Babeyko, Stefano Lorito, Francisco Hernandez, Jörn Lauterjung, Finn Løvholt, Alexander Rudloff, Mathilde Sørensen, Alexey Androsov, Inigo Aniel-Quiroga, Alberto Armigliato, Maria Ana Baptista, Enrico Baglione, Roberto Basili, Jörn Behrens, Beatriz Brizuela, Sergio Bruni, Didem Cambaz, Juan Cantavella Nadal, Fernando Carillho, Ian Chandler, Denis Chang-Seng, Marinos Charalampakis, Lorenzo Cugliari, Clea Denamiel, Gözde Güney Doğan, Gaetano Festa, David Fuhrman, Alice-Agnes Gabriel, Pauline Galea, Steven Gibbons, Mauricio González, Laura Graziani, Marc-André Gutscher, Sven Harig, Helene Hebert, Constantin Ionescu, Fatemeh Jalayer, Nikos Kalligeris, Utku Kânoğlu, Piero Lanucara, Jorge Macias Sánchez, Shane Murphy, Öcal Necmioğlu, Rachid Omira, Gerassimos Papadopoulos, Raphaël Paris, Fabrizio Romano, Tiziana Rossetto, Jacopo Selva, Antonio Scala, Roberto Tonini, Konstantinos Trevlopoulos, Ioanna Triantafyllou, Roger Urgeles, Roberto Vallone, Ivica Vilibić, Manuela Volpe, Ahmet Yalciner, Agencia Estatal de Investigación (España), Andrey Babeyko, Stefano Lorito, Francisco Hernandez, Jörn Lauterjung, Finn Løvholt, Alexander Rudloff, Mathilde Sørensen, Alexey Androsov, Inigo Aniel-Quiroga, Alberto Armigliato, Maria Ana Baptista, Enrico Baglione, Roberto Basili, Jörn Behrens, Beatriz Brizuela, Sergio Bruni, M. Didem Cambaz, Juan Cantavella-Nadal, Fernando Carrilho, Ian Chandler, Denis Chang-Seng, Marinos Charalampakis, Lorenzo Cugliari, Clea Denamiel, Gözde Güney Dogan, Gaetano Festa, David Fuhrman, Alice-Agnes Gabriel, Pauline Galea, Steven J. Gibbons, Mauricio Gonzalez, Laura Graziani, Marc-André Gutscher, Sven Harig, Helen Hebert, Constantin Ionescu, Fatemeh Jalayer, Nikos Kalligeris, Utku Kânoğlu, Piero Lanucara, Jorge Macías Sánchez, Shane Murphy, Öcal Necmioğlu, Rachid Omira, Gerassimos A. Papadopoulos, Raphaël Paris, Fabrizio Romano, Tiziana Rossetto, Jacopo Selva, Antonio Scala, Roberto Tonini, Konstantinos Trevlopoulos, Ioanna Triantafyllou, Roger Urgeles, Roberto Vallone, Ivica Vilibić, Manuela Volpe, Ahmet C. Yalciner, GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Istituto Nazionale di Geofisica e Vulcanologia, Flanders Marine Institute (VLIZ), Norwegian Geotechnical Institute (NGI), University of Bergen (UiB), Alfred Wegener Institute [Potsdam], Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), IHCantabria - Instituto de Hidráulica Ambiental de La Universidad de Cantabria, Santander, Alma Mater Studiorum University of Bologna (UNIBO), Instituto Superior de Engenharia de Lisboa (ISEL), Universität Hamburg (UHH), Kandilli Observatory and Earthquake Research Institute (KOERI), Boǧaziçi üniversitesi = Boğaziçi University [Istanbul], Instituto Geografico Nacional (IGN), Instituto Português de Investigação do Mar e da Atmosfera (IPMA), HR Wallingford Limited, Intergovernmental Oceanographic Commission of UNESCO, Institute of Geodynamics [Athens], National Observatory of Athens (NOA), Institut Ruđer Bošković (IRB), Middle East Technical University [Ankara] (METU), University of Naples Federico II = Università degli studi di Napoli Federico II, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Ludwig-Maximilians-Universität München (LMU), University of Malta [Malta], Geo-Ocean (GEO-OCEAN), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), National Institute for Earth Physics [Romania] - Institutul Național pentru Fizica Pământului (NIEP), CINECA Consorzio Interuniversitario [Rome, Italy], Universidad de Málaga [Málaga] = University of Málaga [Málaga], International Society for the Prevention and Mitigation of Natural Hazards, Athens, Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), University College of London [London] (UCL), Department of Geology and Geoenvironment, National and Kapodistrian University of Athens (NKUA), Centre d'Investigació i Desenvolupament [Barcelona] (CID-CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Project: 262229,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2010-1,EPOS(2010), and Universidad de Cantabria

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Geophysics, Tsunami, Natural hazards, Community building, EPOS, Research infrastructure, Tsunami Natural hazards Community building EPOS Research infrastructure
Abstract

Special issue EPOS a Research Infrastructure in solid Earth: open science and innovation .-- 21 pages, 8 figures, Tsunamis constitute a significant hazard for European coastal populations, and the impact of tsunami events worldwide can extend well beyond the coastal regions directly affected. Understanding the complex mechanisms of tsunami generation, propagation, and inundation, as well as managing the tsunami risk, requires multidisciplinary research and infrastructures that cross national boundaries. Recent decades have seen both great advances in tsunami science and consolidation of the European tsunami research community. A recurring theme has been the need for a sustainable platform for coordinated tsunami community activities and a hub for tsunami services. Following about three years of preparation, in July 2021, the European tsunami community attained the status of Candidate Thematic Core Service (cTCS) within the European Plate Observing System (EPOS) Research Infrastructure. Within a transition period of three years, the Tsunami candidate TCS is anticipated to develop into a fully operational EPOS TCS. We here outline the path taken to reach this point, and the envisaged form of the future EPOS TCS Tsunami. Our cTCS is planned to be organised within four thematic pillars: (1) Support to Tsunami Service Providers, (2) Tsunami Data, (3) Numerical Models, and (4) Hazard and Risk Products. We outline how identified needs in tsunami science and tsunami risk mitigation will be addressed within this structure and how participation within EPOS will become an integration point for community development, With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

Published
2022

11. Exploring the links between volcano flank collapse and the magmatic evolution of an ocean island volcano: Fogo, Cape Verde

Author

Patrick Bachèlery, Régis Doucelance, Abdelmouhcine Gannoun, Delphine Auclair, Chantal Bosq, Mhammed Benbakkar, Raphaël Paris, Hervé Guillou, Melodie-Neige Cornu, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Paléocéanographie (PALEOCEAN), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
Incompatible element, 010504 meteorology & atmospheric sciences, Science, Volcanology, 010502 geochemistry & geophysics, 01 natural sciences, Article, Cape verde, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Caldera, Petrology, 0105 earth and related environmental sciences, geography, Multidisciplinary, geography.geographical_feature_category, Partial melting, Natural hazards, Geochemistry, Volcano, 13. Climate action, Magma, Medicine, Igneous differentiation, Geology
Abstract

Mass-wasting of ocean island volcanoes is a well-documented phenomenon. Massive flank collapses may imply tens to hundreds of km3 and generate mega-tsunamis. However, the causal links between this large-scale, low-frequency instability, and the time–space evolution of magma storage, crystal fractionation/accumulation, lithospheric assimilation, and partial melting remains unclear. This paper aims at tracking time variations and links between lithospheric, crustal and surface processes before and after a major flank collapse (Monte Amarelo collapse ca. 70 ka) of Fogo volcano, Cape Verde Islands, by analysing the chemical composition (major, trace elements, and Sr–Nd–Pb isotopes) and age-controlled stratigraphy (K–Ar and Ar–Ar dating) of lavas along vertical sections (Bordeira caldera walls). The high-resolution sampling allows detecting original variations of composition at different time-scales: (1) a 60 kyrs-long period of increase of magma differentiation before the collapse; (2) a 10 kyrs-long episode of reorganization of magma storage and evacuation of residual magmas (enriched in incompatible elements) after the collapse; and (3) a delayed impact at the lithospheric scale ~ 50 kyrs after the collapse (increasing EM1-like materiel assimilation).

Published
2021

12. The Mediterranean Sea and the Gulf of Cadiz as a natural laboratory for paleotsunami research: Recent advancements

Author

Andreas Vött, Lea Obrocki, Javier Lario, Hanna Hadler, Daniela Pantosti, Beverly Goodman-Tchernov, P. M. De Martini, Raphaël Paris, Klaus Reicherter, Alessandra Smedile, Lisa Feist, Giuseppe Mastronuzzi, Hendrik J. Bruins, Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Roma (INGV), Istituto Nazionale di Geofisica e Vulcanologia, The Jacob Blaustein Institutes for Desert Research (BIDR), Ben-Gurion University of the Negev (BGU), RWTH Aachen University, University of Haifa [Haifa], Johannes Gutenberg - Universität Mainz (JGU), Universidad Estatal a Distancia (UNED), University of Bari Aldo Moro (UNIBA), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and Università degli studi di Bari Aldo Moro = University of Bari Aldo Moro (UNIBA)

Subjects
Archeology, High-resolution studies, 010504 meteorology & atmospheric sciences, 010502 geochemistry & geophysics, Geologic record, 01 natural sciences, Natural (archaeology), Sedimentary structures, Paleontology, Mediterranean sea, Mediterranean Sea, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, 14. Life underwater, Holocene, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, geography, geography.geographical_feature_category, Continental shelf, Geology, Paleotsunami deposits, Coring, Backwash wave, 13. Climate action, General Earth and Planetary Sciences, Submarine pipeline
Abstract

International audience; After the 2004 Indian Ocean (IOT) and the 2011 Tohoku-oki tsunamis, new research in tsunami-related fields was strongly stimulated worldwide and also in the Mediterranean. This research growth yields substantial advancements in tsunami knowledge.Among these advancements is the “Paleotsunami” research that has marked particular progress on the reconstruction of the tsunami history of a region. As an integration of the historical documentation available in the Mediterranean and the Gulf of Cadiz areas, geological and geoarchaeological records provide the insights to define the occurrence, characteristics, and impact of tsunamis of the past. Here, we present the recent advancements done for both the onshore and offshore realms.As for the onshore, we discuss case studies dealing with recent high-resolution works based on: a) direct push in situ sensing techniques, applied to identification and characterization of typical paleotsunami deposits features; b) combined XRF-X-CT approach, implemented for the identification of fine-scale sedimentary structures useful for the definition of the causative flow dynamics; c) the geoarchaeological “new field” contribution, with the development of specific diagnostic criteria in search for tsunami impact traces in archaeological strata; d) comparison of multiple dating methods and of different modeling codes for the definition of the potential source for the displacement of boulders of exceptional dimension, identified by 3D size calculation.As for the offshore advancements, we present case studies focusing on the recognition of tsunami deposits and their sedimentary traces in the geological record from the nearshore, thanks to diver-operated coring equipment, down to the continental slope, by means of vibracorer and long gravity core sampling in deeper areas. The examples provided show a multiproxy approach with a high potential of retrieving a complete record of paleotsunami traces at least during the Holocene. This is based on the combination of multidisciplinary approaches including X-ray imaging, high-resolution measurement of physical properties, X-ray fluorescence data, grain-size analysis, micropaleontology, palynological content, isotopic and optically stimulated luminescence dating methods.

Published
2021

13. Experimental Insights on the Propagation of Fine‐Grained Geophysical Flows Entering Water

Author

Herbert E. Huppert, Olivier Roche, Alexis Bougouin, Raphaël Paris, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institute of Theoretical Geophysics, King's College, University of Cambridge, Cambridge, UK, ANR-16-CE03-0002,RAVEX,Développement d'une approche intégrée pour la réduction des Risques Associés au Volcanisme EXplosif, de la recherche sur l'aléa aux outils de gestion de crise : le cas de la Martinique(2016), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), and ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016)

Subjects
Gravity (chemistry), 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Flow (psychology), geophysical flows, Oceanography, 01 natural sciences, gravity currents, 010305 fluids & plasmas, Physics::Fluid Dynamics, fluidization process, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Fluidization, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Underwater, 0105 earth and related environmental sciences, granular media, Jet (fluid), laboratory experiments, Turbulence, [SDE.IE]Environmental Sciences/Environmental Engineering, Geophysics, 6. Clean water, Gravity current, Space and Planetary Science, Current (fluid), Geology, tsunamis
Abstract

Co-auteur étranger; International audience; Granular flows that propagate down a mountainside, then reach the sea, a lake or a river and finally, travel underwater, is a common event on the Earth’s surface. To help the description of such events, laboratory experiments on gas-fluidized granular flows entering water are performed, analyzed, and compared to those propagating in air. The originality of this study lies in the fluidization process, which improves the laboratory modelling of geophysical flows by taking their high mobility into account. Qualitatively, the presence of the water body promotes the generation of a granular jet over the water surface, a leading and largest wave, and a particle-driven gravity current underwater. Hydrodynamic forces mainly play a dissipative role by slowing and reducing the spreading of the granular mass underwater, but a low amount of grains are still transported by the turbulent fluid as a gravity current far away. The temporal evolution of the granular jet and the particle-driven gravity current are well described by ballistic motion theory and scaling laws of homogeneous gravity currents, respectively. Most currents propagate with a constant flow-front velocity along the horizontal bottom, which is controlled by the flow height depending on the water depth. In constrast, the bulk volume concentration of particles in the current is estimated to be nearly constant, interpreted as a critical concentration above which the excess of particles cannot be maintained by the turbulent fluid. This experimental study highlights the complexity of the dynamics and deposits of granular masses when they encounter a water body.

Published
2021

14. The kingdom of Tonga devastated by a megatsunami in the mid-15th century

Author

Fuka Kitekei’aho, Wassmer Patrick, Franck Lavigne, Tu’I’ahai Tu’I’afitu, Faral Audrey, Mukhamad Ngainul Malawani, Céline Vidal, Weller Olivier, Raphaël Paris, Gomez Christopher, Ana V. Maea, Fatima Mokadem, Ségolène Saulnier-Copard, Julie Morin, Karim Kelfoun, Kula Taaniela, and Mhammed Benbakkar

Subjects
Kingdom, History, Ancient history
Abstract

The pre-colonial history of Tonga and West Polynesia still suffers from major gaps because its reconstruction is essentially based on legends left by oral tradition, and by archaeological evidence somehow difficult to interpret. By the fourteenth century, the powerful Tu'i Tonga kingdom united the islands of the Tongan archipelago under a centralised authority and, according to tradition, extended its influence to neighbouring island groups in the Central Pacific. However, some periods of deep crisis were identified, e.g. in the mid- 15th century, marked by an abrupt cessation of inter-archipelago migration on the deep seas in the Pacific, significant cultural changes, and a decrease in accessible natural resources. The origins of these disturbances are still debated, and are usually assigned to internal political problems or loss of external influence vis-à-vis neighboring states. However, the hypothesis of a major natural disaster was never suggested up to now.Drawing on a body of new evidence from sedimentary signatures and radiocarbon dating of charcoal and marine bioclasts, geomorphology, and sedimentology, in support of previously published archaeological data, we argue that the Tu’i Tonga kingdom was severely impacted by a megatsunami in the mid-15th century. We also discuss the likely sources of this event, which happened in an isolated region of the world before the European maritime “great discoveries”. This tsunami could be the source of vivid local myths that strongly suggest that a giant wave covered almost the entire island of Tongatapu at one time.

Published
2021

15. Complex and prolonged hypercoagulability in coronavirus disease 2019 intensive care unit patients: A thromboelastographic study

Author

Raphaël Paris, Corinne Surcouf, Pierre-Yves Cordier, Arthur Lyochon, Edouard Martin, Claire Contargyris, Candice Pierrou, Hélène Savini, Alexandre Noel, Hélène Astier, Florian Desmots, Frédérik Bélot-De Saint Léger, Eliott Gaudray, Hôpital d'Instruction des Armées Laveran, Service de Santé des Armées, Aix-Marseille Université - École de médecine (AMU SMPM MED), Aix-Marseille Université - Faculté des sciences médicales et paramédicales (AMU SMPM), Aix Marseille Université (AMU)-Aix Marseille Université (AMU), Vecteurs - Infections tropicales et méditerranéennes (VITROME), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut de Recherche Biomédicale des Armées [Brétigny-sur-Orge] (IRBA), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), and Institut de Recherche Biomédicale des Armées (IRBA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)

Subjects
Male, medicine.medical_treatment, Emergency Nursing, Critical Care Nursing, Fibrinogen, law.invention, 0302 clinical medicine, Coagulopathy, law, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Thrombophilia, 030212 general & internal medicine, ComputingMilieux_MISCELLANEOUS, [SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases, medicine.diagnostic_test, Middle Aged, Thrombosis, Intensive care unit, Thrombelastography, Intensive Care Units, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, Cardiology, Female, Research Paper, medicine.drug, medicine.medical_specialty, Critical Care, Pneumonia, Viral, Hypercoagulability, 03 medical and health sciences, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, Intensive care, Internal medicine, Thromboelastography, Fibrinolysis, medicine, Humans, [SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology, Thrombus, Aged, SARS-CoV-2, business.industry, COVID-19, 030208 emergency & critical care medicine, medicine.disease, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Emergency, business
Abstract

Background A high number of thrombotic complications have been reported in critically ill patients with coronavirus disease 2019 (COVID-19) and appear to be related to a hypercoagulable state. Evidence regarding detection, management, and monitoring of COVID-19–associated coagulopathy is still missing. We propose to describe the thrombus viscoelastic properties to investigate the mechanisms of hypercoagulability in patients with COVID-19. Methods Thromboelastography (TEG) was performed in 24 consecutive patients admitted to a single intensive care unit for COVID-19 pneumonia, and 10 had a second TEG before being discharged alive from the intensive care unit. Results Compared with a group of 20 healthy participants, patients with COVID-19 had significantly decreased values of reaction time, coagulation time, and lysis index and increased values of α angle, maximum amplitude, clot strength, and coagulation index. Velocity curves were consistent with increased generation of thrombin. These values persisted in surviving patients despite their good clinical course. Discussion In patients with COVID-19, TEG demonstrates a complex and prolonged hypercoagulable state including fast initiation of coagulation and clot reinforcement, low fibrinolysis, high potential of thrombin generation, and high fibrinogen and platelet contribution. The antithrombotic strategy in patients with COVID-19 during intensive care hospitalisation and after discharge should be investigated in further studies.

Published
2021

16. Advances in the study of mega-tsunamis in the geological record

Author

Hideaki Yanagisawa, Kazuhisa Goto, James Goff, Raphaël Paris, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Science [Tokyo], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), PANGEA Research Centre, UNSW Sydney, Department of Regional Management, Tohoku Gakuin University, Sendai, Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), and The University of Tokyo (UTokyo)

Subjects
010504 meteorology & atmospheric sciences, Earth science, Landslide, 010502 geochemistry & geophysics, Mega, Geologic record, Mega-tsunami, 01 natural sciences, 13. Climate action, Asteroid, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, General Earth and Planetary Sciences, Ocean island, Geology, Asteroid impact, 0105 earth and related environmental sciences
Abstract

International audience; Extreme geophysical events such as asteroid impacts and giant landslides can generate mega-tsunamis with wave heights considerably higher than those observed for other forms of tsunamis. In this paper, we review recent advances in the study of mega-tsunamis in the geological record, focusing on well-documented examples that have captured particular attention over the past decade. We provide up-to-date background on the source mechanisms of tsunami generation during asteroid impacts and ocean-island landslides, which are the largest landslides on Earth. We also discuss the main sources of uncertainty for modelling such mega-tsunamis, and for addressing associated hazards.

Published
2020

17. Analysis of bacterial and archaeal communities associated with Fogo volcanic soils of different ages

Author

Corinne Biderre-Petit, Hélène Gardon, Corentin Hochart, Eric Dugat-Bony, Raphaël Paris, Sébastien Terrat, Isabelle Jouan-Dufournel, Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Paris-Saclay Food and Bioproduct Engineering (SayFood), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Agroécologie [Dijon], Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Ministry of Research, Franceproject PEPS 2015, CNRS, Clermont University Auvergne (UCA), France

Subjects
0301 basic medicine, 030106 microbiology, Weathering, [SDV.BID]Life Sciences [q-bio]/Biodiversity, Biology, Applied Microbiology and Biotechnology, Microbiology, Actinobacteria, Soil, 03 medical and health sciences, Nutrient, RNA, Ribosomal, 16S, Dominance (ecology), Phylogeny, Soil Microbiology, ComputingMilieux_MISCELLANEOUS, Total organic carbon, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, Bacteria, Ecology, 15. Life on land, biology.organism_classification, Archaea, 030104 developmental biology, Microbial population biology, 13. Climate action, Proteobacteria
Abstract

Basaltic rocks play a significant role in CO2 sequestration from the atmosphere during their weathering. Moreover, the primary microorganisms that colonize them, by providing mineral elements and nutrients, are shown to promote growth of diverse heterotrophic communities and plants, therefore positively impacting Earth's long-term climate balance. However, the first steps of microbial colonization and subsequent rock weathering remain poorly understood, especially regarding microbial communities over a chronological sequence. Here, we analyzed the microbial communities inhabiting the soil developed in crevices on lava flows derived from different eruptions on Fogo Island. Investigated soils show typically low carbon and nitrogen content and are relatively similar to one another regarding their phylogenetic composition, and similar to what was recorded in large soil surveys with dominance of Actinobacteria and Proteobacteria. Moreover, our results suggest a stronger effect of the organic carbon than the lava flow age in shaping microbial communities as well as the possibility of exogenous sources of bacteria as important colonizers. Furthermore, archaea reach up to 8.4% of the total microbial community, dominated by the Soil Crenarchaeotic Group, including the ammonium-oxidizer Candidatus Nitrososphaera sp. Therefore, this group might be largely responsible for ammonia oxidation under the environmental conditions found on Fogo.

Published
2020

18. Impact of Fluidized Granular Flows into Water: Implications for Tsunamis Generated by Pyroclastic Flows

Author

Raphaël Paris, Olivier Roche, Alexis Bougouin, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
pyroclastic density current, Mass flux, business.product_category, Turbidity current, Materials science, 010504 meteorology & atmospheric sciences, fluidized granular flow, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Fluid Dynamics, symbols.namesake, Geochemistry and Petrology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Earth and Planetary Sciences (miscellaneous), Froude number, Inclined plane, Porosity, 0105 earth and related environmental sciences, Tsunami, Mechanics, 6. Clean water, Condensed Matter::Soft Condensed Matter, Geophysics, Amplitude, Flow conditions, Space and Planetary Science, symbols, business, Dimensionless quantity
Abstract

International audience; Novel laboratory experiments of fluidized granular flows entering water are reported, for the purpose of investigating tsunamis generated by pyroclastic flows. Qualitatively, the impact of a fluidized granular flow into water leads to (i) an initial vertical granular jet over water, (ii) a leading and largest wave, and (iii) a turbulent mixing zone forming a turbidity current. The present study focuses on the leading wave features in the near‐field region, as a function of the mass flux per width qm and the volume per width υ of the flow, the maximum water depth Ho, and the slope angle θ of the inclined plane. The obtained waves are of Stokes and cnoidal types, for which the generation is mostly controlled by qm and υ. By contrast, Ho plays no role on the wave generation that occurs in the shallowest region. Moreover, a comparison between fluidized granular, dry (nonfluidized) granular, and water flows entering water is addressed under similar flow conditions. The dimensionless amplitude scales as A/Ho=f(ζ), where urn:x-wiley:jgrb:media:jgrb54190:jgrb54190-math-0001 is a dimensionless parameter depending on the Froude number Fr, the relative slide thickness S, the relative mass M, and the slope angle θ. Data of fine fluidized granular, fine dry granular, and water flows collapse on a master curve, which implies that the nature of the flowing material is of lesser importance in the current setup. By contrast, coarse granular flows generate lower amplitude waves, which is attributed to the penetration of water into the porous granular medium.

Published
2020

19. Frontiers in Marine Science

Author

Rónadh Cox, Fabrice Ardhuin, Frédéric Dias, Ronan Autret, Nicole Beisiegel, Claire S. Earlie, James G. Herterich, Andrew Kennedy, Raphaël Paris, Alison Raby, Pál Schmitt, Robert Weiss, Center for Coastal Studies, Geosciences, Department of Geosciences, Williams College, Williamstown, MA, UCD Earth Institute, University College Dublin, Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), School of Mathematics and Statistics, University College Dublin, Laboratoire de Dynamique et de Gestion Intégrée des Zones Côtières (LDGIZC), Université du Québec à Rimouski (UQAR), School of Earth and Ocean Sciences [Cardiff], Cardiff University, College of Engineering, Notre Dame University, Notre Dame, IN, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Plymouth University, Queen's University [Belfast] (QUB), Department of Geosciences, Virginia Tech, Blacksburg, VA, Center for Coastal Studies, Virginia Tach, Blacksburg, VA, Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and School of Engineering, University of Plymouth, Plymouth

Subjects
0106 biological sciences, lcsh:QH1-199.5, 010504 meteorology & atmospheric sciences, Ocean Engineering, lcsh:General. Including nature conservation, geographical distribution, Coastal geography, Hazard analysis, Aquatic Science, Environmental Science (miscellaneous), Oceanography, 01 natural sciences, Wave height, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Hindcast, coastal boulder deposits, 14. Life underwater, SDG 14 - Life Below Water, lcsh:Science, 0105 earth and related environmental sciences, Wave power, Water Science and Technology, coastal erosion, Global and Planetary Change, Coastal hazards, coastal geomorphology, 010604 marine biology & hydrobiology, Storm, coastal hazard, Coastal erosion, storm waves, 13. Climate action, wave modeling, hydrodynamic equations, lcsh:Q, tsunami, Geology, Seismology
Abstract

Coastal boulder deposits (CBD), transported by waves at elevations above sea level and substantial distances inland, are markers for marine incursions. Whether they are tsunami or storm deposits can be difficult to determine, but this is of critical importance because of the role that CBD play in coastal hazard analysis. Equations from seminal work by Nott (1997), here referred to as the Nott Approach, are commonly employed to calculate nominal wave heights from boulder masses as a means to discriminate between emplacement mechanisms. Systematic review shows that this approach is based on assumptions that are not securely founded and that direct relationships cannot be established between boulder measurements and wave heights. A test using an unprecedented dataset of boulders moved by storm waves (with associated sea-state data) shows a lack of agreement between calculations and actual wave heights. The equations return unrealistically large heights, many of which greatly exceed sea states occurring during the boulder-moving storms. This underscores the finding that Nott-Approach wave-height calculations are unreliable. The result is general, because although the field data come from one region (the Aran Islands, Ireland), they represent a wide range of boulder masses and topographic settings and present a valid test of hydrodynamic equations. This analysis demonstrates that Nott Approach equations are incapable of distinguishing storm waves from tsunami transport and that wave heights hindcast from boulder masses are not meaningful. Current hydrodynamic understanding does not permit reliable computation of wave height from boulder measurements. A combination of field, numerical, and experimental approaches is required to quantify relationships between wave power and mass transport onshore. Many CBD interpreted as tsunami deposits based on Nott-Approach analysis may in fact have been emplaced during storms and should therefore be re-evaluated. This is especially important for CBD that have been incorporated into long-term coastal risk assessments, which are compromised if the CBD are misinterpreted. CBD dynamics can be better determined from a combination of detailed field measurements, modeling, and experiments. A clearer understanding of emplacement mechanisms will result in more reliable hazard analysis. US-Ireland R&D Partnership Programme, by National Science Foundation award [1529756]; Science Foundation Ireland (SFI)Science Foundation Ireland [14/US/E3111]; Department for the Economy Northern Ireland [USI801]; SFI Centre for Marine and Renewable Energy (MaREI) [12/RC/2302]; World Faculty Fellowship through Williams College; National Science Foundation awardNational Science Foundation (NSF) [1661015] Research was supported under the US-Ireland R&D Partnership Programme, by National Science Foundation award 1529756 (RC); Science Foundation Ireland (SFI) award 14/US/E3111 (FD, NB, and JH); and Department for the Economy Northern Ireland Grant USI801 (PS). FD also acknowledges SFI award 12/RC/2302 through the SFI Centre for Marine and Renewable Energy (MaREI), and RC acknowledges additional support from a World Faculty Fellowship through Williams College. AK acknowledges National Science Foundation award 1661015.

Published
2020

20. Sedimentary fabric characterised by X-ray tomography: A case-study from tsunami deposits on the Marquesas Islands, French Polynesia

Author

Pascal Doumalin, James Goff, Catherine Chagué, Raphaël Paris, Samuel Etienne, Simon Falvard, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Royal Holloway [University of London] (RHUL), Littoral, Environnement, Télédétection, Géomatique (LETG - Dinard), Littoral, Environnement, Télédétection, Géomatique UMR 6554 (LETG), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN)-Université de Caen Normandie (UNICAEN), Université de Nantes (UN)-Université de Nantes (UN), Université Paris sciences et lettres (PSL), École Pratique des Hautes Études (EPHE), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), and École pratique des hautes études (EPHE)

Subjects
Marquesas Islands, 010506 paleontology, Stratigraphy, X-ray, Mineralogy, Geology, Sedimentary fabric, 010502 geochemistry & geophysics, 01 natural sciences, Pacific ocean, Grain size, Bulk samples, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Sedimentary rock, High angle, 14. Life underwater, Tomography, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Anisotropy, X-ray tomography, 0105 earth and related environmental sciences, Tsunami deposits
Abstract

co-auteur étranger; International audience; X‐ray tomography is used to analyse the grain size and sedimentary fabric of two tsunami deposits in the Marquesas Islands (French Polynesia, Pacific Ocean) which are particularly exposed to trans‐Pacific tsunamis. One site is located on the southern coast of Nuku Hiva Island (Hooumi) and the other one is on the southern coast of Hiva Oa Island (Tahauku). Results are compared with other techniques such as two‐dimensional image analysis on bulk samples (particle analyser) and anisotropy of magnetic susceptibility. The sedimentary fabric is characterized through three‐dimensional stacks of horizontal slices (following a vertical step of 2·5 mm along the cores), while grain‐size distribution is estimated from two‐dimensional vertical slices (following a step of 2 mm). Four types of fabric are distinguished: (a) moderate to high angle (15 to 75°); (b) bimodal low‐angle (

Published
2020

21. Mega-tsunami deposits related to ocean island flank collapses and asteroid impacts

Author

Raphaël Paris

Subjects
Flank, Asteroid, Magnitude (mathematics), Mega, Seismology, Geology, Term (time)
Abstract

The term “mega-tsunami” refers to tsunamis with a magnitude that exceeds all published tsunami magnitude scales. Among all possible source mechanisms of tsunamis, only large flank collapses of ocean islands and asteroid impacts have the potential to generate mega-tsunamis. However, the magnitude of tsunamis that could potentially be generated by such exceptional events is debated. There is no doubt that wave runup can reach several tens or even hundreds of meters in the proximal zone (

Published
2020

22. The December 22, 2018 Anak Krakatau, Indonesia, Landslide and Tsunami: Preliminary Modeling Results

Author

Philippe Heinrich, Alexandre Paris, Raphaël Paris, Stéphane Abadie, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire des Sciences de l'Ingénieur Appliquées à la Mécanique et au génie Electrique (SIAME), Université de Pau et des Pays de l'Adour (UPPA), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, Water flow, Submarine, Landslide, 010502 geochemistry & geophysics, 01 natural sciences, Waves and shallow water, Geophysics, Volcano, 13. Climate action, Geochemistry and Petrology, Subaerial, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Bathymetry, Tide gauge, 14. Life underwater, Geology, Seismology, 0105 earth and related environmental sciences
Abstract

International audience; On the evening of December 22, 2018, the coasts of the Sunda Strait, Indonesia, were hit by a tsunami generated by the collapse of a part of the Anak Krakatau volcano. Hundreds of people were killed, thousands were injured and displaced. This paper presents a preliminary modeling of the volcano flank collapse and the tsunami generated based on the results of a 2D depth-averaged coupled model involving a granular rheology and a Coulomb friction for the slide description and dispersive effects for the water flow part. With a reconstructed total volume (subaerial and submarine) of the landslide of 150 million m 3 inferred from pre and post-collapse satellite and aerial images , the comparison of the simulated water waves with the observations (tide gauges located all around the strait, photographs and field surveys) is satisfactory. Due to the lack of information for the submarine part of the landslide, 2 Alexandre Paris et al. the reconstructed submarine slope is assumed to be approximately constant. A significant time delay on the results and particularly in the Bandar Lampung Bay could be attributed to imprecisions of bathymetric data. The sensitivity to the basal friction and to dispersive effects is analyzed through numerical tests. Results show that the influence of the basal friction angle on the simulated wave heights decreases with distance and that a value of 2°gives consistent results with the observations. The dispersive effects are assessed by comparing water waves simulated by a shallow water model and a Boussinesq model. Simulations with frequency dispersion produce longer wave periods and smaller wave amplitudes in the Sunda Strait and particularly in deep waters.

Published
2020

23. Contributors

Author

Daisuke Araoka, Ronan Autret, Joanne Bourgeois, Dominik Brill, Charles S. Bristow, Helmut Brückner, Catherine Chagué, Marinos Charalampakis, Pedro J.M. Costa, Sue Dawson, Alastair Dawson, Dale Dominey-Howes, Tina Dura, Max Engel, Wibke Erdmann, Eric Font, Ed Garrett, James Goff, Christopher Gomez, Beverly N. Goodman-Tchernov, Kazuhisa Goto, Chris Gouramanis, Andrea D. Hawkes, Eileen Hemphill-Haley, Vanessa M.A. Heyvaert, Dirk Hoffmeister, Fumihiko Imamura, T. Yan W.M. Iskandarsyah, Dieter Kelletat, Harvey M. Kelsey, Akihisa Kitamura, Yuho Kumagai, A.Y. Annie Lau, Alessandra Maramai, Simon Matthias May, Koji Minoura, Katrin Monecke, Hiroyuki Nagahama, Norihiro Nakamura, N.A.K. Nandasena, Mikhail Nosov, Jan Oetjen, Gerassimos A. Papadopoulos, Raphaël Paris, Tasnim Patel, Jan Pawłowski, Jessica Pilarczyk, Tatiana K. Pinegina, Gilles Rixhon, Tetsuro Sato, Anja Scheffers, Isa Schön, Holger Schüttrumpf, Klaus Schwarzer, Alexander R. Simms, Michaela Spiske, Daisuke Sugawara, Adam D. Switzer, Witold Szczuciński, Toru Tamura, Davin J. Wallace, Patrick Wassmer, Masashi Watanabe, Robert C. Witter, Jonathan D. Woodruff, and Masaki Yamada

Published
2020

24. Comprehensive care documentation: A first step not to be missed

Author

Raphaël Paris, Eliott Gaudray, Philippe Goutorbe, Salah Boussen, Edouard Martin, Pierre-Yves Cordier, Hôpital d'Instruction des Armées Laveran, Service de Santé des Armées, Laboratoire de Biomécanique Appliquée (LBA UMR T24), Aix Marseille Université (AMU)-Université Gustave Eiffel, and Hopital d'instruction des armées Sainte-Anne [Toulon] (HIA)

Subjects
Medical education, business.industry, [SDV]Life Sciences [q-bio], 030208 emergency & critical care medicine, Documentation, Emergency Nursing, Critical Care Nursing, 03 medical and health sciences, Intensive Care Units, 0302 clinical medicine, Medicine, Humans, 030212 general & internal medicine, business, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2020

25. X-ray tomography applied to tsunami deposits

Author

Raphaël Paris

Subjects
Mineralogy, Tomography, Deposition (chemistry), Geology
Abstract

Since the 2004 tsunami, our knowledge of tsunami deposition has progressed considerably, thanks to an important mobilization of the scientific community, but also thanks to various methodological developments. Among recent methods applied to tsunami deposits, X-ray tomography is filling a gap. Little is known about the micromorphology of these complex deposits and its relationships with flow dynamics. In this chapter, I introduce the basics of X-ray tomography and provide examples of its application to tsunami deposits.

Published
2020

26. Probabilistic Tsunami Hazard Analysis: Multiple Sources and Global Applications

Author

Rachid Omira, Tom Parsons, Jacopo Selva, Antonio Costa, Stefano Lorito, William Power, Jörn Behrens, Gareth E. Davies, F. I. Gonzalez, Jonathan Griffin, Jascha Polet, Sylfest Glimsdal, Randall J. LeVeque, Maria Ana Baptista, Christof Mueller, Mathilde B. Sørensen, Raphaël Paris, Eric L. Geist, Finn Løvholt, Carl B. Harbitz, Hong Kie Thio, Anita Grezio, and Andrey Babeyko

Subjects
Tsunami wave, 010504 meteorology & atmospheric sciences, Probabilistic logic, Landslide, 010502 geochemistry & geophysics, 01 natural sciences, Hazard, Geophysics, Probabilistic method, 13. Climate action, Tsunami hazard, Environmental science, 14. Life underwater, Probabilistic framework, Uncertainty analysis, Seismology, 0105 earth and related environmental sciences
Abstract

Applying probabilistic methods to infrequent but devastating natural events is intrinsically challenging. For tsunami analyses, a suite of geophysical assessments should be in principle evaluated because of the different causes generating tsunamis (earthquakes, landslides, volcanic activity, meteorological events, and asteroid impacts) with varying mean recurrence rates. Probabilistic Tsunami Hazard Analyses (PTHAs) are conducted in different areas of the world at global, regional, and local scales with the aim of understanding tsunami hazard to inform tsunami risk reduction activities. PTHAs enhance knowledge of the potential tsunamigenic threat by estimating the probability of exceeding specific levels of tsunami intensity metrics (e.g., run-up or maximum inundation heights) within a certain period of time (exposure time) at given locations (target sites); these estimates can be summarized in hazard maps or hazard curves. This discussion presents a broad overview of PTHA, including (i) sources and mechanisms of tsunami generation, emphasizing the variety and complexity of the tsunami sources and their generation mechanisms, (ii) developments in modeling the propagation and impact of tsunami waves, and (iii) statistical procedures for tsunami hazard estimates that include the associated epistemic and aleatoric uncertainties. Key elements in understanding the potential tsunami hazard are discussed, in light of the rapid development of PTHA methods during the last decade and the globally distributed applications, including the importance of considering multiple sources, their relative intensities, probabilities of occurrence, and uncertainties in an integrated and consistent probabilistic framework.

Published
2017

27. A tsunami deposit at Anse Meunier, Martinique Island: Evidence of the 1755 CE Lisbon tsunami and implication for hazard assessment

Author

Jean Roger, Gaël André, Maude Biguenet, Alexis Bougouin, Pierre Sabatier, and Raphaël Paris

Subjects
geography, Marsh, geography.geographical_feature_category, location.country, Geology, Hazard analysis, Oceanography, location, Stratigraphy, Geochemistry and Petrology, Martinique island, Period (geology), Coastal flood
Abstract

This study presents the results of paleo-tsunami investigation in marshes of the southern and eastern coasts of Martinique Island (Lesser Antilles, France). A sand unit dated 1726–1813 cal. CE at 30 cm depth at Anse Meunier represents the most convincing evidence of high-energy coastal flooding of the last 5000 years on the island. Sedimentological analyses combined with tsunami simulations demonstrate that this sand deposit likely corresponds to the 1755 CE Lisbon transatlantic tsunami. No other tsunami or hurricane event was identified on the 11 marshes investigated. The 1755 Lisbon tsunami is thus the only tsunami recorded in the stratigraphy of coastal marshes of the southern and eastern coasts of Martinique Island during the last 3500 years, even if we cannot exclude the possibility of larger-magnitude but lower-frequency tsunamis that would not be recorded in coastal stratigraphy during this period.

Published
2021

28. The use of vascular plant densities to estimate the age of undated lava flows in semi-arid areas of Fogo Island (Cape Verde, Atlantic Ocean)

Author

Samuel Etienne, Raphaël Paris, Sébastien Larrue, Laboratoire de Géographie Physique et Environnementale (GEOLAB), Centre National de la Recherche Scientifique (CNRS)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne (UCA), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Cognitions Humaine et ARTificielle (CHART), École pratique des hautes études (EPHE)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), ANR-10-LABX-0006/10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR: 16-IDEX-0001,CAP 20-25,CAP 20-25 (I-Site)(2017), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Université Paris 8 Vincennes-Saint-Denis (UP8)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Nanterre (UPN)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Paris 8 Vincennes-Saint-Denis (UP8)-École pratique des hautes études (EPHE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Clermont Auvergne (UCA)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Paris Nanterre (UPN)-Université Paris 8 Vincennes-Saint-Denis (UP8)-École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
0106 biological sciences, Vascular plant, Volcanic hazards, 010504 meteorology & atmospheric sciences, Lava, Insular biogeography, Chronosequence, Ecological succession, 010603 evolutionary biology, 01 natural sciences, Cape verde, Semi-arid lava flows, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, vascular plants, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth-Surface Processes, Ecology, biology, island biogeography, 15. Life on land, biology.organism_classification, Arid, [SDE.ES]Environmental Sciences/Environmental and Society, chronosequence, [SDE]Environmental Sciences, Physical geography, volcanic island, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Geology
Abstract

The age of some lava flows on the east-north-east coast of Fogo Island (Cape Verde) remains debated or unknown due to the inapplicability of conventional dating methods. Dating information is important for a retrospective approach to volcanic hazard evaluation and prevention. Historical lavas represent an opportunity to study plant succession within a well-constrained chronological framework, and lava flow age has often been used as a variable to explain plant densities and species composition. Here, vascular plant densities were also assigned as variables to explain lava ages. We surveyed 44 plots on eleven semi-arid lavas among which nine represented a chronosequence of 60- c. 350-yr-old lavas, while two other lavas remained undated. We used principal component analysis (PCA) to test the relationships between species densities and lava ages. A stepwise regression model was then used to identify which species were more closely related to the age of lavas, and the best fit of the model was employed to predict the age of the undated lavas. Spearman’ test was used to observe the correlations among lavas and the result was compared with regression model age-predictions for the undated lavas. Among 27 vascular plants, nine species were significantly linked with lava ages. The stepwise model showed that lava ages were significantly explained by the densities of Sarcostemma daltonii and Lantana camara species. Stepwise model age-predictions were congruent with Spearman’ results, supporting the proposition that vascular plant species densities can provide useful information about the relative age of undated lava flows in arid environments.

Published
2019

29. Coherence change analysis for multipass InSAR images based on the change detection matrix

Author

Alexis Hrysiewicz, Jean-Luc Froger, Raphaël Paris, Thu Trang Le, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Coherence time, 010401 analytical chemistry, 020206 networking & telecommunications, 02 engineering and technology, Change analysis, 01 natural sciences, 0104 chemical sciences, 13. Climate action, Interferometric synthetic aperture radar, 0202 electrical engineering, electronic engineering, information engineering, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Coherence (signal processing), Change detection, Geology, Remote sensing
Abstract

International audience; This paper presents an approach for Interferometric Synthetic Aperture Radar (InSAR) coherence change analysis. This approach is based on the Change Detection Matrix (CDM) which allows the identification of the presence of changes on the ground. Coherence images are first computed from InSAR image time series (ITS) between each two adjacent dates. The CDM approach is then applied to study the obtained coherence time series with patch-wise analysis. The preliminary results on damage mapping related to the tsunami induced by the eruption of Krakatoa volcano, Sunda Strait, Indonesia on December 22, 2018 using Sentinel-1 InSAR ITS have shown the relevancy of the proposed approach.

Published
2019

30. SO2 and tephra emissions during the December 22, 2018 Anak Krakatau flank-collapse eruption

Author

Mathieu Gouhier, Raphaël Paris, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Daytime, 010504 meteorology & atmospheric sciences, Geochemistry, Geology, 010502 geochemistry & geophysics, 01 natural sciences, Anak Krakatau, Plume, Atmosphere, Geophysics, 13. Climate action, Geochemistry and Petrology, Magma, Subaerial, Earth and Planetary Sciences (miscellaneous), Phreatomagmatic eruption, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Tephra, Volcanic ash, SO2 degassing, Flank Collapse, 0105 earth and related environmental sciences
Abstract

On December 22, 2018 the south-western flank of Anak Krakatau collapsed into the sea, removing 93.8 × 106 m3 of subaerial lavas, and generated a tsunami. Synchronously with the collapse, a large volcanic plume of SO2 and ash (14–15 km in height) has formed, marking the onset of a paroxysmal eruption lasting from December 22, 2018 to January 06, 2019. From remote sensing analysis, we show that the eruption can be divided into three main phases. Phase I and II show both tephra and gas emissions while phase III is mostly degassing. The total amount of SO2 injected in the atmosphere is 173±52 kt, while the minimum bulk magma volume emplaced, estimated from a topographic reconstruction, is ?45 × 106 m3. This value compares well with a petrologic-based estimate of 56.4 × 106 m3, making the existence of external sulphur sources and sinks quite unlikely. The ice-rich ash plume formation shows that a strong sea-water/magma interaction was responsible for the phreatomagmatic activity throughout the eruption. However, we distinguish a first Vulcanian blast-derived eruption (lasting 40 min) just after the collapse having a Mass Eruption Rate (MER) of 9 × 105 kgs?1, followed by a sustained lower-intensity eruption resulting in ash emissions over hours (MER = 5 × 105 kgs?1). From December 23, daytime photos show typical Surtseyan activity.

Published
2019

31. Numerical modelling of the December 22, 2018 Anak Krakatau landslide and the following tsunami in Sunda Strait, Indonesia

Author

Alexandre Paris, Cyrielle Guérin, Hélène Hébert, Philippe Heinrich, Audrey Gailler, Raphaël Paris, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Jouhannel, Sylvaine, Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Numerical modeling, Landslide, Numerical models, 010502 geochemistry & geophysics, 01 natural sciences, Volcano, [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Tide gauge, 14. Life underwater, Geology, Seismology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

In the evening on December 22, 2018, the Sunda Strait, Indonesia, suffered a destructive tsunami that no one had seen coming. It killed more than 400 people, injured and displaced thousands more. Post event satellite images indicate that the tsunami was probably caused by the collapse of a part of the southwestern flank of the Anak Krakatau volcano. Assuming a landslide volume of 150 million m3 sliding into water as a granular flow under gravity forces, the simulated water waves are in general agreement with the tide gauges that recorded the tsunami.

Published
2019

32. Tsunamis generated by subaqueous volcanic explosions in Taal Caldera Lake, Philippines

Author

Raphaël Paris, Martina Ulvrova, Laboratoire Magmas et Volcans (LMV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Jean Monnet [Saint-Étienne] (UJM), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Jouhannel, Sylvaine, Laboratoires d'excellence - Clermont-Ferrand centre for research on volcanism - - CLERVOLC2010 - ANR-10-LABX-0006 - LABX - VALID, CAP 20-25 - - CAP 20-252016 - ANR-16-IDEX-0001 - IDEX - VALID, Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
010504 meteorology & atmospheric sciences, Explosive material, Philippines, Subaqueous explosion, Hazard analysis, 010502 geochemistry & geophysics, 01 natural sciences, Lake, Geochemistry and Petrology, Taal volcano, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Caldera, Sedimentology, 0105 earth and related environmental sciences, Phreatomagmatism, Shore, geography, geography.geographical_feature_category, Tsunami, Surface displacement, Volcano, 13. Climate action, [SDU]Sciences of the Universe [physics], [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, Geology, Seismology
Abstract

International audience; Volcanic subaqueous explosions can generate hazardous tsunamis, especially in lakes. In this paper, we simulate different scenarios of subaqueous explosions and related tsunamis in Taal Caldera Lake (Luzon, Philippines). Taal volcano is one of the most active volcanoes in Southeast Asia, and eruptive processes are mostly explosive. We test different energies of explosions at eight different explosion sites in the lake. The initial water surface displacement ( ƞ 0) generated by the explosion is estimated as a function of explosion energy at a given depth. We estimate the tsunami travel times, maximum wave heights, and wave periods at the shoreline. This type of hazard is typically neglected and our work has important implications for hazard assessment around Taal Lake. Due to fast propagation of tsunamis in the lake (waves typically crossing the lake in less than 10 min), there is only a short time available for issuing a warning. For ƞ 0 ≤ 50 m, wave heights at the shoreline are less than 2 m with a non-dispersive numerical model, and less than 0.5 m with a dispersive model, whatever the explosion depth and location. Powerful explosions with ƞ 0 > > 100 m generate wave heights greater than 2 m all around the lake and local peaks higher than 10 m.

Published
2019

33. Probabilistic hazard analysis for tsunamis generated by subaqueous volcanic explosions in the Campi Flegrei caldera, Italy

Author

Martina Ulvrova, Stefano Lorito, Anita Grezio, Roberto Tonini, Beatriz Brizuela, Raphaël Paris, Jacopo Selva, Antonio Costa, Paris, R., Ulvrova, M., Selva, J., Brizuela, B., Costa, A., Grezio, A., Lorito, S., Tonini, R., Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Sciences de la Terre (LST), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), CHI Poissy-Saint-Germain, ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), and Jouhannel, Sylvaine

Subjects
010504 meteorology & atmospheric sciences, Magnitude (mathematics), Hazard analysis, 010502 geochemistry & geophysics, 01 natural sciences, Geochemistry and Petrology, caldera, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Caldera, 14. Life underwater, Submarine volcanic explosions, Submarine volcanic explosion, Underwater, ComputingMilieux_MISCELLANEOUS, Volcanic tsunami, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Submarine, Hazard, Campi Flegrei caldera, Geophysics, Volcano, 13. Climate action, [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, Caldera volcano, Campi Flegrei, Bay, Seismology, Geology
Abstract

Co-auteur étranger; International audience; A probabilistic hazard analysis of tsunami generated by subaqueous volcanic explosion is applied to the Campi Flegrei caldera (Campania, Italy). An event tree is developed to quantify the tsunami hazard due to the submarine explosions by: i) defining potential size classes of explosion magnitude on the basis of past volcanic activity in the Campi Flegrei caldera and sites in the underwater part of the caldera; ii) simulating the generation and propagation of the consequent tsunami waves able to reach the coasts of the Campania region for all combinations of tsunami-generating vents and sizes; and iii) quantifying the tsunami probability and relative uncertainty, conditional upon the occurrence of an underwater eruption at Campi Flegrei. Tsunami hazard generated by subaqueous volcanic explosions is considered crucial because of its potential high impact on the densely populated coastal areas of the Pozzuoli Bay and Gulf of Naples even if the probability for eruptions in the submarine part of the caldera is certainly low. The tsunami hazard analysis is presented using conditional hazard curves and maps, that is calculating the probability (and relative uncertainties) of exceeding given tsunami intensity thresholds (wave amplitudes at the coast), given the occurrence of a subaqueous eruption. The results indicate that a significant tsunami hazard exists in many areas of the Bay of Naples.

Published
2019

34. Mantle plumes are oxidised

Author

Clive Oppenheimer, Marc-Antoine Longpré, Alejandra Gómez-Ulla, Bruno Scaillet, Catherine McCammon, Nial Peters, Emanuela Gennaro, Estelle Rose-Koga, Yves Moussallam, Raphaël Paris, Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Queens College [New York], City University of New York [New York] (CUNY), Bayerisches Geoinstitut (BGI), Universität Bayreuth, Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Magma - UMR7327, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Department of Geography [Cambridge, UK], University of Cambridge [UK] (CAM), Instituto Nazionale di Geofisica e Vulcanologie Sezione di Palermo, CNRS INSU-TelluS-SYSTER, ANR-10-LABX-0100,VOLTAIRE,Geofluids and Volatil elements – Earth, Atmosphere, Interfaces – Resources and Environment(2010), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC)

Subjects
010504 meteorology & atmospheric sciences, oxygen fugacity degassing XANES melt inclusions mantle plumes, Geochemistry, 010502 geochemistry & geophysics, melt inclusions, 01 natural sciences, Mantle plume, Mantle (geology), Cape verde, mantle plumes 20 21, Geochemistry and Petrology, Mineral redox buffer, Hotspot (geology), Earth and Planetary Sciences (miscellaneous), 14. Life underwater, 0105 earth and related environmental sciences, Melt inclusions, Basalt, Subduction, oxygen fugacity, degassing, XANES, mantle plumes, Geophysics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Geology
Abstract

International audience; From oxic atmosphere to metallic core, the Earth's components are broadly stratified with respect to oxygen fugacity. A simple picture of reducing oxygen fugacity with depth may be disrupted by the accumulation of oxidised crustal material in the deep lower mantle, entrained there as a result of subduction. While hotspot volcanoes are fed by regions of the mantle likely to have incorporated such recycled material, the oxygen fugacity of erupted hotspot basalts had long been considered comparable to or slightly more oxidised than that of mid-ocean ridge basalt (MORB) and more reduced than subduction zone basalts. Here we report measurements of the redox state of glassy crystal-hosted melt inclusions from tephra and quenched lava samples from the Canary and Cape Verde Islands, that we can independently show were entrapped prior to extensive sulphur degassing. We find high ferric iron to total iron ratios (Fe3+/∑Fe) of up to 0.27–0.30, indicating that mantle plume primary melts are significantly more oxidised than those associated with mid-ocean ridges and even subduction zone. These results, together with previous investigations from the Erebus, Hawaiian and Icelandic hotspots, confirm that mantle upwelling provides a return flow from the deep Earth for components of oxidised subducted lithosphere and suggest that highly oxidised material accumulates or is generated in the lower mantle. The oxidation state of the Earth's interior must therefore be highly heterogeneous and potentially locally inversely stratified.

Published
2019

35. Ten years since the 2011 Tohoku-oki tsunami – Progress in paleotsunami research

Author

Raphaël Paris, James Goff, Kazuhisa Goto, Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)

Subjects
[SDU]Sciences of the Universe [physics], [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, General Earth and Planetary Sciences, Geology
Abstract

International audience; The Year 2021 is 10 years since the 2011 off the Pacific Coast of Tohoku Earthquake and Tsunami (Tohoku-oki tsunami). This was the first time that such a large tsunami had occurred at a place where advanced paleotsunami research had been ongoing since the early 1990's and where the risk of such an event had been highlighted by geologists (Goto et al., 2021). This anniversary therefore represents an important time for Earth scientists to remind the world about the risk of such low frequency, but large tsunamis. This special issue aims to not only review the 2011 Tohoku-oki tsunami, but also the progress that has been made in paleotsunami research since the event both in Japan and around the world.

Published
2021

36. X-ray tomography of tsunami deposits: Towards a new depositional model of tsunami deposits

Author

Raphaël Paris and Simon Falvard

Subjects
010504 meteorology & atmospheric sciences, Stratigraphy, Geology, 010502 geochemistry & geophysics, 01 natural sciences, Traction (geology), Sedimentary depositional environment, Settling, Clastic rock, Shear stress, Sedimentary rock, Tomography, Anisotropy, Seismology, 0105 earth and related environmental sciences
Abstract

X-ray computed microtomography is used to obtain high resolution imagery of a historical tsunami deposit in Andalusia, Spain (1755 Lisbon tsunami). The technique allows characterization of grain-size distribution, structures, component analysis and sedimentary fabric of fine-grained unconsolidated tsunami deposits at resolutions down to particle scale. The results are validated by comparing to data obtained using other techniques such as laser diffraction, anisotropy of magnetic susceptibility and X-ray microfluorescence on the same deposits. Specific technical details such as sampling, scanning and image processing methods, and further improvements are addressed. The use of X-ray computed microtomography provides new insights into the stratigraphy of the deposits and gives access to significantly more detailed view of key sedimentary features such as mudlines, rip-up clasts, crude laminations, convolutions, floating outsized clasts and contacts between successive units. This analysis of the 1755 tsunami deposits using X-ray computed microtomography allows the proposal of new hypotheses for the sedimentary processes forming tsunami deposits. Deposition by settling is limited and the section analysed here is dominated by a high shear stress leading to the development of traction carpets, with laminated mudlines corresponding to the basal frictional region of these carpets. The onset of the tsunami backwash is marked by a micro-vortex resembling Kelvin–Helmoltz instabilities.

Published
2016

37. A mid-Holocene candidate tsunami deposit from the NW Cape (Western Australia)

Author

Manuel Dierick, Simon Falvard, Max Engel, Anna Pint, Peter Squire, Maike Norpoth, Raphaël Paris, Simon Matthias May, Dominik Brill, Anja Scheffers, Helmut Brückner, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Cologne, Southern Cross GeoScience, Southern Cross University (SCU), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Range (biology), Stratigraphy, Palaeotsunami deposit, 010502 geochemistry & geophysics, 01 natural sciences, Deposition (geology), Foraminifera, Paleontology, Peninsula, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Coastal flood, Holocene, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Sediment fabric, biology, Sediment, Geology, biology.organism_classification, Optically stimulated luminescence, Oceanography, X-ray microtomography, Clastic rock
Abstract

International audience; Although extreme-wave events are frequent along the northwestern coast of Western Australia and tsunamis in 1994 and 2006 induced considerable coastal flooding locally, robust stratigraphical evidence of prehistoric tropical cyclones and tsunamis from this area is lacking. Based on the analyses of X-ray computed microtomography (μCT) of oriented sediment cores, multi-proxy sediment and microfaunal analyses, optically stimulated luminescence (OSL) and 14C-AMS dating, this study presents detailed investigations on an allochthonous sand layer of marine origin found in a back-barrier depression on the NW Cape Range peninsula. The event layer consists of material from the adjacent beach and dune, fines and thins inland, and was traced up to ~ 400 m onshore. Although a cyclone-induced origin cannot entirely be ruled out, the particular architecture and fabric of the sediment, rip-up clasts and three subunits point to deposition by a tsunami. As such, it represents the first stratigraphical evidence of a prehistoric, mid-Holocene tsunami in NW Western Australia. It was OSL-dated to 5400–4300 years ago, thus postdating the regional mid-Holocene sea-level highstand.

Published
2016

38. Maintien dans l’emploi des personnes présentant un trouble bipolaire

Author

Emma Beetlestone, Raphaël Paris, Marie-Pascale Lehucher-Michel, Elise Marion-Paris, and Antoine Villa

Subjects
Public Health, Environmental and Occupational Health
Abstract

Objectif Au moins la moitie des personnes touchees par un trouble bipolaire, dont la prevalence mondiale est superieure a 1 % de la population generale, n’a pas d’activite professionnelle stable. L’objectif de cette etude est de recenser les facteurs percus par les personnes bipolaires comme ayant un impact sur leur maintien dans l’emploi. Methode Des entretiens individuels semi-diriges ont ete proposes aux sujets presentant un trouble bipolaire, en âge de travailler, et ayant frequente 3 services hospitaliers de l’Assistance publique des Hopitaux de Marseille. Ces personnes devaient etre stabilisees medicalement et avoir vecu au moins une experience professionnelle. Chaque entretien a ete enregistre et retranscrit manuellement puis analyser selon un classement thematique des verbatims. Resultats Dix-neuf personnes ont participe aux entretiens. Trois themes majeurs identifies ont ete classes en facteurs intrinseques (rythme de travail, cadre ou contexte de travail) et extrinseques (aides exterieures) a la personne bipolaire. La majorite des sujets estime que le travail a horaires reguliers est un facteur d’equilibre. Pour tous, le travail de nuit et les facteurs de stress peuvent entrainer des rechutes. Tous soulignent la necessite de destigmatiser la maladie aupres des employeurs et mettre en avant leurs competences. La plupart estime qu’il faut developper des organismes d’accompagnement a l’emploi specifiques aux maladies psychiques. Conclusion Cette recherche contribue a renseigner les sujets presentant un trouble bipolaire sur les facteurs professionnels impactant l’equilibre de leur affection. Des parcours de soin personnalises pluridisciplinaires impliquant la medecine du travail, sont a developper afin de favoriser l’equilibre de la maladie et leur maintien dans l’emploi.

Published
2020

39. The Holocene volcanism of Gran Canaria (Canary Islands, Spain)

Author

Francisco-Jose Perez-Torrado, J. L. Fernandez-Turiel, Claudio Moreno-Medina, Meritxell Aulinas, Raphaël Paris, Alejandro Rodriguez-Gonzalez, Departamento de Física, University of Las Palmas de Gran Canaria (ULPGC), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Ministerio de Educación y Ciencia (España), Gobierno de Canarias, Universidad de Las Palmas de Gran Canaria, Fernandez-Turiel, J. L., and Fernandez-Turiel, J. L.[0000-0002-4383-799X]

Subjects
lcsh:Maps, Holocene volcanism, Gran Canària (Canàries), 010504 meteorology & atmospheric sciences, Holocene, Geography, Planning and Development, Gran Canaria, Canary Islands, Volcanism, 010502 geochemistry & geophysics, Geologic map, 01 natural sciences, Paleontology, geological map, lcsh:G3180-9980, Vulcanisme, Earth and Planetary Sciences (miscellaneous), [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Holocè, Gran Canaria (Canary Islands), Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

This work presents the first detailed map of the Holocene eruptions of Gran Canaria (Canary Islands, Spain). It provides complete and detailed information for all 24 Holocene eruptions of Gran Canaria, improving the knowledge of this recent volcanism and the assessment of volcanic hazards on the island. This map is a synthesis of collated and interpreted field data and topographic maps. We have integrated information obtained from: (1) detailed geological field surveys, (2) morphometric analysis of eruptive deposits, (3) high-resolution digital elevation models, and (4) aerial photographs., The research carried out to develop this map, including field work, radiometric dating, geomorphology, petrology and geochemistry, was funded by the Spanish Ministry of Education and Science for the research project CGL2004-04039/BTE and the Canarian Government for the research project PI2002/148; Instituto de Estudios Ambientales y Rercursos natuales (i-UNAT), ULPGC.

Published
2018

40. Scenario of the 1996 volcanic tsunamis in Karymskoye Lake, Kamchatka, inferred from X-ray tomography of heavy minerals in tsunami deposits

Author

Simon Falvard, Alexander Belousov, Marina Belousova, Stéphanie Cuven, Raphaël Paris, Thomas Giachetti, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Earth Observatory of Singapore (EOS), Nanyang Technological University [Singapour], Laboratoire de Géographie Physique et Environnementale (GEOLAB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Clermont Auvergne (UCA)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Provenance, Heavy minerals, 010504 meteorology & atmospheric sciences, Geochemistry, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Deposition (geology), Lake, Karymskoye, Geochemistry and Petrology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, 14. Life underwater, Underwater, 0105 earth and related environmental sciences, Basalt, Shore, geography, geography.geographical_feature_category, Tsunami, Sediment, Geology, Phreato-magmatic eruption, Volcano, Clastic rock, X-ray tomography, Seismology
Abstract

co-auteur étranger; International audience; The concentration and distribution of heavy minerals in tsunami deposits is not random and mostly sourcedependent.Heavy minerals may thus be good indicators of sediment provenance and tsunami flow dynamics.The tsunamis generated by the 1996 phreato-magmatic eruption in Karymskoye Lake represent a relevant casestudybecause the provenance of the abundant heavy minerals found in the tsunami deposits is well constrained(the on-going basaltic eruption itself). X-ray computed tomography (X-CT) of cores of tsunami sediments is usedto identify heavy minerals and characterise their source and spatial distribution in the tsunami deposit, and topropose a scenario of the coupled eruption and tsunamis. An original combination of methods including X-CT,SEM and XRF core scanner allows distinguishing subunits corresponding to pulses of sediments deposition andassociated inputs of heavy minerals, together with erosive contacts, laminations, and rip-up clasts of thesubstratum. The structure of the tsunami deposits suggests that a major tsunami consisting of two main wavesinundated the coastal terrace up to 100 m inland on the eastern shore of the lake; a scenario that is consistentwith waves generated by experimental explosions. This largest tsunami might have occurred when underwaterexplosions were at a critical water depth of 40 m (corresponding to a two-third submerged explosion in the 60 mdeep lake). However, more investigations are needed to better understand the critical conditions leading to atsunami during underwater eruptions.

Published
2018

41. Mega-tsunami conglomerates and flank collapses of ocean island volcanoes

Author

Gerd Schukraft, Manuel Herzog, Thomas Giachetti, José Madeira, Alejandro Rodriguez-Gonzalez, Max Engel, Francisco-Jose Perez-Torrado, Gilles Rixhon, Helmut Brückner, Ricardo S. Ramalho, Juan Carlos Carracedo, Simon Matthias May, Raphaël Paris, Sérgio P. Ávila, Laboratoire Magmas et Volcans (LMV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Jean Monnet [Saint-Étienne] (UJM), Grupo de concepção e analise de dispositivos eletromagnéticos (GRUCAD), Universidade Federal de Santa Catarina = Federal University of Santa Catarina [Florianópolis] (UFSC), University of Cologne, Estacion Volcanologica de Canarias IPNA-CSIC, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Department of Earth Sciences [Eugene OR], University of Oregon [Eugene], ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Flank, 010504 meteorology & atmospheric sciences, Canary Islands, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Pacific ocean, Hawaii, Conglomerate, Cape verde, Oceanic shield volcanoes, Geochemistry and Petrology, Volcano instability, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, 14. Life underwater, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Tsunami, Geology, Landslide, Numerical models, Indian ocean, Cape Verde Islands, Volcano
Abstract

Co-auteur étranger; International audience; Marine conglomerates at high elevation on the flanks of ocean islands are usually interpreted as evidence of mega-tsunamis generated by volcano flank collapses, although their origin is sometimes debated (elevated littorals vs. tsunami). In this review, we introduce case studies of well-documented examples of tsunami conglomerates in Hawaii (Pacific Ocean), the Canary and Cape Verde Islands (Atlantic Ocean), and Mauritius Island (Indian Ocean). Other less-documented marine conglomerates are also presented as tsunami candidates. Then, we build a comprehensive picture of the general characteristics of these conglomerates and the different methods that can be applied to date them. Different perspectives of research are proposed, especially on the use of tsunami conglomerates as proxies for better constraining numerical models of ocean island flank collapses and associated tsunamis. We also discuss the possible links between volcano growth, flank instability, and climate.

Published
2018

42. Simulating the thermorheological evolution of channel-contained lava: FLOWGO and its implementation in EXCEL

Author

Lucia Gurioli, Nicolas Villeneuve, M. Rhéty, Raphaël Paris, and Andrew J. L. Harris

Subjects
010504 meteorology & atmospheric sciences, Lava, Geology, Ocean Engineering, Geometry, Geophysics, 010502 geochemistry & geophysics, 01 natural sciences, Control volume, Viscosity, Line (geometry), Newtonian fluid, Gradient descent, Bingham plastic, 0105 earth and related environmental sciences, Water Science and Technology, Communication channel
Abstract

FLOWGO is a one-dimensional model that tracks the thermorheological evolution of lava flowing down a channel. The model does not spread the lava but, instead, follows a control volume as it descends a line of steepest descent centred on the channel axis. The model basis is the Jeffreys equation for Newtonian flow, modified for a Bingham fluid, and a series of heat loss equations. Adjustable relationships are used to calculate cooling, crystallization and down- channel increases in viscosity and yield strength, as well as the resultant decrease in velocity. Here we provide a guide that allows FLOWGO to be set up in Excel. In doing so, we show how the model can be executed using a slope profile derived from Google TM Earth. Model simplicity and ease of source-term input from Google TM Earth means that this exercise allows (i) easy access to the model, (ii) quick, global application and (iii) use in a teaching role. Output is tested using measurements made for the 2010 eruption of Piton de la Fournaise (La Reunion Island). The model is also set up for rapid syneruptive hazard assessment at Piton de la Fournaise, as we show using the example of the response to the June 2014 eruption.

Published
2015

43. GPR-derived architecture of a lahar-generated fan at Cotopaxi volcano, Ecuador

Author

Susanne Ettinger, Sarah Kruse, Raphaël Paris, Vern Manville, Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géographie Physique et Environnementale (GEOLAB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institute of Geophysics and Tectonics, School of Earth and Environment, University of Leeds, College of Arts & Sciences, University of South Florida [Tampa] (USF), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Clermont Auvergne (UCA)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Lahar, Pyroclastic rock, Context (language use), 010502 geochemistry & geophysics, 01 natural sciences, Lapilli, Ground penetrating radar, Stratigraphy, Aggradation, Architecture, Ground-penetrating radar, Facies, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Sediment, Ecuador, Volcano, Geomorphology, Geology, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract

International audience; The internal geometry of volcaniclastic fans produced by aggradation during lahar events is difficult to examine in modern settings because of the frequent lack of three-dimensional exposures. This makes it challenging to (i) reconstruct the spatial and temporal evolution of such fans; and (ii) interpret observed facies stratigraphy in the context of lahar flow dynamics from proximal to distal fan reaches. This research therefore presents the results of a ground penetrating radar (GPR) survey of the Rumipamba fan at the mouth of the Burrohuaycu quebrada on the southwestern flank of Cotopaxi volcano. A survey grid consisting of 50 individual GPR profiles representing a total length of 19.4 km was constructed covering most of the 4-km2 large fan surface. All GPR profiles were collected using a PulseEKKO 100 with a 400 V transmitter. Fan sediments consist of sandy and gravelly lahar deposits, alternating with volcanic fallout including ash and pumice lapilli, at times reworked by fluvial processes. Deposits could be ground-truthed to a depth of ~3 m, whereas GPR penetration depth reaches 15 m. Data interpretation was based on classification into 15 distinct radar facies characterized by the nature of their bounding surfaces and/or internal features, cross-referenced where possible with shallow exposures. Three main facies were identified: parallel, irregular, and clinoform. Erosional contacts were distinguished from aggradational ones (vertical, channel fill, and lateral accretion). Flow parallel versus flow transverse and proximal–distal variations in deposit architecture were featured. The results of this study confirm the existence of two major channel systems in the northern and southern extremities of the fan and the more recent formation of a smaller central fan channel system. Deposit architecture is complex and facies chronologies illustrate that lahars have affected the entire survey area.

Published
2014

44. High-resolution analysis of a tsunami deposit: Case-study from the 1755 Lisbon tsunami in southwestern Spain

Author

Simon Falvard, Elisabeth Miot-Noirault, Jean-Luc Schneider, Mhammed Benbakkar, Raphaël Paris, Stéphanie Cuven, and Isabelle Billy

Subjects
High resolution analysis, Sediment Analysis, Geochemistry and Petrology, Sorting (sediment), Trench, Sediment, Geology, Oceanography, Bay, Deposition (geology), Seismology
Abstract

A multi-proxy approach using trench sediment analysis on the southwestern coast of Spain (Los Lances Bay, Andalusia) provides a high-resolution record of the 1755 Lisbon tsunami and offers new means to interpret tsunami deposits. A combination of sedimentological (grain size, sorting, AMS), micromorphological (X-ray tomography and radiography, thin sections) and geochemical analyses (X-ray microfluorescence, ICP-AES) combines to provide a comprehensive reconstruction of the different phases of tsunami deposition and flow dynamics. Vertical variations in sediment texture, fabric and composition of the 1755 tsunami deposits in Los Lances are then discussed with reference to existing literature on diagnostic criteria commonly used for identifying and interpreting tsunami deposits. Finally possible leads for future investigation are proposed.

Published
2013

45. Source of the tsunami generated by the 1650 AD eruption of Kolumbo submarine volcano (Aegean Sea, Greece)

Author

F.W. Mccoy, Martina Ulvrova, David R. Tappin, Paraskevi Nomikou, Sébastien Leibrandt, Raphaël Paris, Karim Kelfoun, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Kingsley Dunham Centre, British Geological Survey (BGS), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Pyroclastic flow, Pyroclastic rock, Submarine volcanism, 010502 geochemistry & geophysics, 01 natural sciences, Geochemistry and Petrology, Aegean Sea, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Caldera, 14. Life underwater, Geomorphology, Submarine volcano, 0105 earth and related environmental sciences, Explosive eruption, Santorini, Tsunami, Kolumbo volcano, Submarine, Subsidence, Caldera collapse, Geophysics, 13. Climate action, Subaerial, Underwater explosion, Sedimentary rock, Geology, Seismology
Abstract

International audience; The 1650 AD explosive eruption of Kolumbo submarine volcano (Aegean Sea, Greece) generated a destructive tsunami. In this paper we propose a source mechanism of this poorly documented tsunami using both geological investigations and numerical simulations. Sedimentary evidence of the 1650 AD tsunami was found along the coast of Santorini Island at maximum altitudes ranging between 3.5 m a.s.l. (Perissa, southern coast) and 20 m a.s.l. (Monolithos, eastern coast), corresponding to a minimum inundation of 360 and 630 m respectively. Tsunami deposits consist of an irregular 5 to 30 cm thick layer of dark grey sand that overlies pumiceous deposits erupted during the Minoan eruption and are found at depths of 30–50 cm below the surface. Composition of the tsunami sand is similar to the composition of the present-day beach sand but differs from the pumiceous gravelly deposits on which it rests. The spatial distribution of the tsunami deposits was compared to available historical records and to the results of numerical simulations of tsunami inundation. Different source mechanisms were tested: earthquakes, underwater explosions, caldera collapse, and pyroclastic flows. The most probable source of the 1650 AD Kolumbo tsunami is a 250 m high water surface displacement generated by underwater explosion with an energy of ~ 2 × 1016 J at water depths between 20 and 150 m. The tsunamigenic explosion(s) occurred on September 29, 1650 during the transition between submarine and subaerial phases of the eruption. Caldera subsidence is not an efficient tsunami source mechanism as short (and probably unrealistic) collapse durations (< 5 min) are needed. Pyroclastic flows cannot be discarded, but the required flux (106 to 107 m3 · s− 1) is exceptionally high compared to the magnitude of the eruption.

Published
2016
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46. Microtextural characteristics of quartz grains transported and deposited by tsunamis and storms

Author

William C. Mahaney, Pedro Costa, César Andrade, Rui Taborda, Alastair G. Dawson, Maria da Conceição Freitas, and Raphaël Paris

Subjects
Sedimentary depositional environment, High energy, Stratigraphy, Geochemistry, Sediment, Geology, Storm, Sedimentary rock, Laboratory experiment, Quartz, Sediment concentration, Geomorphology
Abstract

article i nfo The complex transport and depositional processes associated with tsunamis and storms and the peculiarities of local inundation present questions associated with the recognition and differentiation of the sedimentary signature of these events. This work presents a study of quartz grains transported and deposited by tsunami and storm waves with the objective of identifying specific microtextural signatures caused by high-energy marine inundations and to correlate them with their principal sedimentary sources. In this empirical study, 1150 quartz grains (78 samples) and their microtextural signatures were observed, analyzed and classified using scanning electron microscope photomicrographs. The results suggest that although no specific microtextural signature is associated with high energy inundations, there are strong increases in the percent- age of fresh surfaces and percussion marks when compared with the potential source material. Moreover, tsunami and storm grains present the greatest microtextural variance among all the grains analyzed. Never- theless, specific local conditions and sediment concentrations constrain the microtextural implications on tsunami or storm grains. One laboratory experiment was designed to test microtextural implications in grains subjected to variable velocities, sediment concentration and time. The surface microscopic signature in quartz grains of high-energy events further contributes to the development of more efficient sedimentological criteria to identify deposits associated with tsunami and storm events.

Published
2012

47. Modeling of coastal erosion and sediment deposition during the 2004 Indian Ocean tsunami in Lhok Nga, Sumatra, Indonesia

Author

Akira Mano, Budianto Ontowirjo, and Raphaël Paris

Subjects
Atmospheric Science, Sediment, Debris, Deposition (geology), Coastal erosion, Oceanography, Natural hazard, Earth and Planetary Sciences (miscellaneous), Erosion, Geomorphology, Sediment transport, Geology, Water Science and Technology, Bed load
Abstract

This study presents the results of numerical simulations of the 2004 Indian Ocean earthquake and tsunami in the Bay of Lhok Nga (northwestern coast of Sumatra, Indonesia) integrating sediment erosion and deposition. We investigate the transport of sediment both by suspension and by bedload under different scenarii of long breaking dispersive waves through a series of numerical experiments. The earthquake source model used by Koshimura et al. (Coast Eng J 51:243–273, 2008) with a 25-m dislocation better reproduces the wave travel time, flow depth and inundation area than the other models tested. The model reproduces realistically the pronounced coastal retreat in the northern part of Lhok Nga Bay (retreat ranging between 50 and 150 m), where Paris et al. (Geomorphology 104:59–72, 2009) estimated a mean retreat of 80 m. There is also a good agreement between the simulated area of coastal retreat (195,400 m2) and the field observations (203,200 m2). The simulation may underestimate the volume of tsunami deposits (611,700 m3 vs. 500,000–1,000,000 m3 estimated by Paris et al. (2009). The model fully reproduces the observed thickness of tsunami deposits when considering both bedload and suspension, even if bedload transport dominates. Limitations are due to micro-scale topographic, anthropic features (which are not always represented by the DEM) and the amount of debris which may influence flow dynamics and sediment transport.

Published
2012

49. Numerical assessment of boulder transport by the 2004 Indian ocean tsunami in Lhok Nga, West Banda Aceh (Sumatra, Indonesia)

Author

Raphaël Paris, N.A.K. Nandasena, and Norio Tanaka

Subjects
Seawall, Indian ocean, Subaerial, Finite difference method, Banda aceh, Current velocity, Numerical assessment, Computers in Earth Sciences, Seismology, Geology, Information Systems, Field observation
Abstract

Few studies have been conducted on modeling boulder transport by tsunamis despite considerable research on the analysis of boulder deposits. A detailed description of the derivation of governing equations for boulder transport in submerged, partially submerged, and subaerial (not in contact with fluid) is presented, and then a numerical model is proposed to solve the governing equations in one dimension. Subsequently, the model is used to analyze the transport of calcareous boulders detached from a seawall in Lhok Nga (northwestern Sumatra, Indonesia) by the 2004 Indian Ocean tsunami. A few simulated transport distances match field observations, but the others are higher than the field measurements. Clast-to-clast interactions at the inception of transport would have a major impact on changes in transport distance, dissipating the energy in impulses as destruction of the seawall releases different sizes of boulders with different velocities. Moreover, surface microtopographical effects could completely stop the transport prematurely. The difference between the simulated results and the field observations is partly attributed to limitations of the numerical model. No landward fining was observed in the field measurements, but numerically predicted results showed a reasonable trend of landward fining.

Published
2011

50. Numerical modelling of the tsunami triggered by the Güìmar debris avalanche, Tenerife (Canary Islands): Comparison with field-based data

Author

Karim Kelfoun, Francisco-Jose Perez-Torrado, Raphaël Paris, and Thomas Giachetti

Subjects
Outcrop, Collapse (topology), Geology, Landslide, Hazard analysis, Oceanography, Debris, Current (stream), Geochemistry and Petrology, Subaerial, Submarine pipeline, Geomorphology, Seismology
Abstract

Some tsunami deposits have been previously identified 41–188 m asl in the Agaete Valley on the northwest coast of the island of Gran Canaria, in the Canary Islands. In this paper, the Guimar sector collapse (Tenerife, ~ 0.83 Ma), and its expected associated tsunami that is thought to be at the origin of these tsunami deposits, are tentatively reproduced using a two-fluid numerical code. Two failure processes are considered: 1) the whole 44 km 3 volume is released in one go, or 2) the 44 km 3 are released in five retrogressive failures of equal volume, occurring each 120 s. In both cases, two rheologies are used to simulate the landslide propagation: the Mohr–Coulomb frictional law and a constant retarding stress. Two hypotheses concerning the origin of the offshore mapped deposits are also considered: 1) the mapped deposits are the direct result of a single collapse event occurring either in one go or by near retrogressive failures, or 2) the mapped deposits result from a collapse followed by later partial remobilization of its deposits. In all scenarios, the subaerial destabilisation spreads out eastwards into the sea, triggering waves 390–500 m high when considering a collapse in one go, and 225–380 m when considering successive retrogressive failures. The first wave reaches the coast of Gran Canaria, located at 70 km from the scar, 495–560 s after the collapse onset, whatever the scenario considered. Water enters the Agaete Valley on Gran Canaria 555–690 s after the onset of collapse, reaching up to 9.1 km inland for a collapse in one go, and 5.0 km when considering five retrogressive failures. In this valley, the simulated waves inundate all the locations where tsunami deposits were identified, with the flow depth measured reaching a maximum of 50 m (collapse by retrogressive failures) to 150 m (collapse in one go) at these particular places. The directions of maximum kinetic energy as a function of time for the simulated waves are consistent with the current directions recorded by the cobble fabrics present in the run-up and backwash layers of the tsunami deposits at one outcrop. This study shows that the major source of uncertainty when reproducing landslide-triggered tsunamis is linked to the way the landslide happens (failure mechanisms), that should be thus more precisely taken into account for landslide-triggered-tsunamis hazard assessment. The rheology chosen to simulate the landslide propagation has only a second-order impact on the produced waves.

Published
2011

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