Search

Your search keyword '"E. J. Rindraharisaona"' showing total 6 results
Start Over Author "E. J. Rindraharisaona" Topic 14. life underwater
6 results on '"E. J. Rindraharisaona"'

1. ReNovRisk: a multidisciplinary programme to study the cyclonic risks in the South-West Indian Ocean

Author

Alicia Gonzalez, Sabine Garabedian, Claire Rault, Kevin Samyn, David Nortes-Martinez, Dominique Mekies, Soline Bielli, Guillaume Payen, Gwenaëlle Pennober, Florian Jouvenot, Fabrice R. Fontaine, Christelle Barthe, Joris Pianezze, E. J. Rindraharisaona, Julien Cattiaux, Jean-Lambert Join, Idriss Fontaine, Jean-Pierre Cammas, Pascal Mouquet, Bertrand Aunay, Remi Belon, Fabrice Chauvin, Pierre Tulet, Callum Thompson, François Bonnardot, Franck Gabarrot, Olivier Bousquet, Guilhem Barruol, Hélène Vérèmes, Christophe Révillion, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Météo France, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Centre d'Économie et de Management de l'Océan Indien (CEMOI), Université de La Réunion (UR), UMR 228 Espace-Dev, Espace pour le développement, Université de Guyane (UG)-Université des Antilles (UA)-Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Météo-France Direction Interrégionale Sud-Est (DIRSE), Météo-France, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Université de Guyane (UG)-Université des Antilles (UA)

Subjects
Tropical cyclone, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric Science, 010504 meteorology & atmospheric sciences, Climate change, Structural basin, 010502 geochemistry & geophysics, 01 natural sciences, Interdisciplinary programme, Indian ocean, Geography, 13. Climate action, Multidisciplinary approach, Natural hazard, Earth and Planetary Sciences (miscellaneous), Cyclone, 14. Life underwater, Cyclonic hazards, Resilience (network), Indian Ocean, Environmental planning, 0105 earth and related environmental sciences, Water Science and Technology
Abstract

Today, resilience in the face of cyclone risks has become a crucial issue for our societies. With climate change, the risk of strong cyclones occurring is expected to intensify significantly and to impact the way of life in many countries. To meet some of the associated challenges, the interdisciplinary ReNovRisk programme aims to study tropical cyclones and their impacts on the South-West Indian Ocean basin. This article is a presentation of the ReNovRisk programme, which is divided into four areas: study of cyclonic hazards, study of erosion and solid transport processes, study of water transfer and swell impacts on the coast, and studies of socio-economic impacts. The first transdisciplinary results of the programme are presented together with the database, which will be open access from mid-2021.

Published
2021
Full Text
View/download PDF

2. Impact of Tropical Cyclones on Inhabited Areas of the SWIO Basin at Present and Future Horizons. Part 2: Modeling Component of the Research Program RENOVRISK-CYCLONE

Author

Fabrice Chauvin, Olivier Bousquet, Jonas Zucule, Frauke Fleischer-Dogley, Quoc-Phi Duong, Edouard Lees, Romain Husson, Alexis Mouche, Callum Thompson, Emmanuel Cordier, François Bonnardot, Radiance Calmer, Navalona Manitriniana Ravoson, Guilhem Barruol, Vincent Amelie, M. Singh, Julien Cattiaux, Bruno Razafindradina, Nicolas Marquestaut, Sylvie Malardel, Alberto Mavume, Chia-Lun Tsai, Stéphane Ciccione, Dominique Mekies, Soline Bielli, Joris Pianezze, M Claeys, E. J. Rindraharisaona, Christelle Barthe, Lova Zakariasy, Gregory Roberts, Pierre Tulet, Jonathan Durand, Marie-Noëlle Bouin, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Institute for Coastal Marine Research (CMR), Nelson Mandela University, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Center for Atmospheric REmote Sensing (CARE), Kyungpook National University [Daegu], Direction Interrégionale de Météo-Franc pour l'océan Indien, 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)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Seychelles Meteorological Authority, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, National Snow and Ice Data Center (NSIDC), University of Colorado [Boulder], Kélonia - Observatoire des tortues marines, Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Seychelles Islands Foundation (SIF), Collecte Localisation Satellites (CLS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National d'Études Spatiales [Toulouse] (CNES), Eduardo Mondlane University, Institut et Observatoire de Géophysique d’Antisiranana (IOGA), Institut Supérieur de Technologie d’Antisiranana, Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, Mauritius Oceanography Institute, University of Mauritius, Instituto Nacional de Meteorologia (INAM), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Kyungpook National University [Daegu] (KNU), Direction Interrégionale de Météo-France pour l'océan Indien (DIROI), Météo-France, 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), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Scripps Institution of Oceanography (SIO - UC San Diego), and University of California (UC)-University of California (UC)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, tropical cyclone, ocean-wave-atmosphere coupling, Climate change, Context (language use), Environmental Science (miscellaneous), 01 natural sciences, Meteorology. Climatology, 14. Life underwater, climate modeling, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, cloud-resolving model, geography.geographical_feature_category, Microphysics, 010505 oceanography, Global warming, ocean–wave–atmosphere coupling, 13. Climate action, Climatology, Archipelago, south-west Indian ocean, Environmental science, Cyclone, Climate model, Tropical cyclone, QC851-999
Abstract

International audience; The ReNovRisk-Cyclone program aimed at developing an observation network in the south-west Indian ocean (SWIO) in close synergy with the implementation of numerical tools to model and analyze the impacts of tropical cyclones (TC) in the present and in a context of climate change. This paper addresses the modeling part of the program. First, a unique coupled system to simulate TCs in the SWIO is developed. The ocean–wave–atmosphere coupling is considered along with a coherent coupling between sea surface state, wind field, aerosol, microphysics, and radiation. This coupled system is illustrated through several simulations of TCs: the impact of air–sea flux parameterizations on the evolution of TC Fantala is examined, the full coupling developed during the program is illustrated on TC Idai, and the potential of novel observations like space-borne synthetic aperture radar and sea turtles to validate the atmosphere and ocean models is presented with TC Herold. Secondly, the evolution of cyclonic activity in the SWIO during the second half of the 21st century is assessed. It was addressed both using climate simulation and through the implementation of a pseudo global warming method in the high-resolution coupled modeling platform. Our results suggest that the Mascarene Archipelago should experience an increase of TC related hazards in the medium term.

Published
2021
Full Text
View/download PDF

3. Impact of Tropical Cyclones on Inhabited Areas of the SWIO Basin at Present and Future Horizons. Part 1: Overview and Observing Component of the Research Project RENOVRISK-CYCLONE

Author

Joris Pianezze, M Claeys, E. J. Rindraharisaona, Pierre Tulet, Bruno Razafindradina, Guilhem Barruol, Romain Husson, Callum Thompson, François Bonnardot, Chia-Lun Tsai, Frauke Fleischer-Dogley, Christelle Barthe, Lova Zakariasy, M. Singh, Julien Cattiaux, Nicolas Marquestaut, Alberto Mavume, Fabrice Chauvin, Stéphane Ciccione, Jonas Zucule, Dominique Mekies, Gregory Roberts, Jonathan Durand, Olivier Bousquet, Emmanuel Cordier, Edouard Lees, Alexis Mouche, Radiance Calmer, Vincent Amelie, Soline Bielli, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Institute for Coastal Marine Research (CMR), Nelson Mandela University, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), National Snow and Ice Data Center (NSIDC), University of Colorado [Boulder], Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), Seychelles Meteorological Authority, Seychelles Islands Foundation (SIF), Eduardo Mondlane University, Institut Supérieur de Technologie d’Antisiranana, Direction Interrégionale de Météo-France pour l'océan Indien (DIROI), Météo-France, Mauritius Oceanography Institute, University of Mauritius, Collecte Localisation Satellites (CLS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National d'Études Spatiales [Toulouse] (CNES), 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), Kélonia - Observatoire des tortues marines, Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Scripps Institution of Oceanography (SIO), University of California-University of California, Direction Interrégionale de Météo-Franc pour l'océan Indien, and 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)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, tropical cyclone, gliders, Satellite system, Environmental Science (miscellaneous), Structural basin, sea turtles, 010502 geochemistry & geophysics, 01 natural sciences, seismic data, biologging, Meteorology. Climatology, 14. Life underwater, south-west Indian Ocean, unmanned airborne system, 0105 earth and related environmental sciences, Atmospheric sounding, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, global satellite navigation system, ReNovRisk, austral and cyclonic swells, numerical modelling, climate modelling, Drone, Swell, 13. Climate action, GNSS applications, Cyclone, Environmental science, QC851-999, Tropical cyclone
Abstract

International audience; The international research program “ReNovRisk-CYCLONE” (RNR-CYC, 2017–2021) directly involves 20 partners from 5 countries of the south-west Indian-Ocean. It aims at improving the observation and modelling of tropical cyclones in the south-west Indian Ocean, as well as to foster regional cooperation and improve public policies adapted to present and future tropical cyclones risk in this cyclonic basin. This paper describes the structure and main objectives of this ambitious research project, with emphasis on its observing components, which allowed integrating numbers of innovative atmospheric and oceanic observations (sea-turtle borne and seismic data, unmanned airborne system, ocean gliders), as well as combining standard and original methods (radiosoundings and global navigation satellite system (GNSS) atmospheric soundings, seismic and in-situ swell sampling, drone and satellite imaging) to support research on tropical cyclones from the local to the basin-scale.

Published
2021
Full Text
View/download PDF

4. Cyclone Signatures in the South-West Indian Ocean from Two Decades of Microseismic Noise

Author

E. J. Rindraharisaona, Fabrice R. Fontaine, Emmanuel Cordier, Guilhem Barruol, Alicia Gonzalez, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Observatoire volcanologique et sismologique de martinique (OVSM), Institut de Physique du Globe de Paris, Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)

Subjects
Atmospheric Science, Microseism, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], microseismic noise, lcsh:QC851-999, Environmental Science (miscellaneous), Seismic noise, 010502 geochemistry & geophysics, 01 natural sciences, Wind speed, Seismic wave, 13. Climate action, Wave height, Cyclone, Hindcast, lcsh:Meteorology. Climatology, tropical cyclones, 14. Life underwater, Tropical cyclone, Indian Ocean, Seismology, Geology, wave height, 0105 earth and related environmental sciences
Abstract

Tropical Cyclones (TC) represent the most destructive natural disaster affecting the islands in the South-West Indian Ocean (SWIO) each year. Monitoring ocean activity is therefore of primary importance to secure lands, infrastructures and peoples, but the little number of oceanographic instruments makes it challenging, particularly in real time. Long-term seismological records provide a way to decipher and quantify the past cyclonic activity by analyzing microseisms, seismic waves generated by the ocean activity and propagating through the solid Earth. In the present study, we analyze this microseismic noise generated by cyclones that develop in the SWIO basin between 1999 and 2020, using broadband seismic stations in La Réunion. The power spectral density (PSD), together with the root mean square (RMS) analyses of continuous seismic data recorded by the permanent Geoscope RER seismic station, indicate the intensification of the microseismic noise amplitude in proportion to the cyclone intensity. Thus, we establish a relationship between the cyclone intensity and the PSD of the Secondary Microseisms (SM) in frequency band ∼0.14 to 0.25 Hz (4 to 7 s period). The Pearson coefficient between the observed and estimated TC intensity are &gt, 0.8 in the presence of a cyclone with mean wind speeds &gt, 75 km/h and with a seismic station distance-to-storm center D &lt, 3000 km. A polarization analysis in the time and frequency domains allows the retrieval of the backazimuth of the SM sources during isolated cyclone events and well-polarized signal, i.e., CpH &gt, 0.6. We also analyzed the RMS of the Primary Microseisms (PM frequency between ∼0.05 and 0.1 Hz, i.e., for 10 to 20 s period) for cyclones passing nearby La Réunion (D &lt, 500 km), using the available temporary and permanent broadband seismic stations. We also found high correlation coefficients (&gt, 0.8) between the PM amplitude and the local wave height issued from the global hindcast model demonstrating that the PM amplitude can be used as a robust proxy to perform a real-time wave-height monitoring in the neighboring ocean. Transfer functions are calculated for several cyclones to infer wave height from the seismic noise amplitude recorded on land. From the analysis of two decades of data, our results suggest that it is possible to quantify the past ocean activity for as long as continuous seismic archives are available, emphasizing microseismic noise as a key observable for quantifying and understanding the climate change.

Published
2021
Full Text
View/download PDF

5. Crustal structure of southern Madagascar from receiver functions and ambient noise correlation: Implications for crustal evolution

Author

Georg Rümpker, Guilhem Barruol, Gérard Rambolamanana, Frederik Tilmann, Xiaohui Yuan, Jörg Giese, and E. J. Rindraharisaona

Subjects
geography, geography.geographical_feature_category, Rift, 010504 meteorology & atmospheric sciences, Continental collision, Subduction, Proterozoic, Continental crust, Archean, Geochemistry, Crust, Geophysics, Sedimentary basin, 010502 geochemistry & geophysics, 01 natural sciences, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), 14. Life underwater, Geology, 0105 earth and related environmental sciences
Abstract

The Precambrian rocks of Madagascar were formed and/or modified during continental collision known as the Pan-African orogeny. Aborted Permo-Triassic Karoo rifting and the subsequent separation from Africa and India resulted in the formation of sedimentary basins in the west and volcanic activity predominantly along the margins. Many geological studies have documented the imprint of these processes, but little was known about the deeper structure. We therefore deployed seismic stations along an SE-NW trending profile spanning nearly all geological domains of southern Madagascar. Here, we focus on the crustal structure, which we determined based on joint analysis of receiver functions and surface waves derived from ambient noise measurements. For the sedimentary basin we document a thinning of the underlying crystalline basement by up to ∼60% to 13 km. The crustal velocity structure demonstrates that the thinning was accomplished by removal or exhumation of the lower crust. Both the Proterozoic and Archean crust have a 10 km thick upper crust and 10-12 km thick midcrust. However, in contrast to the typical structure of Proterozoic and Archean aged crust, the Archean lower crust is thicker and faster than the Proterozoic one, indicating possible magmatic intrusions; an underplated layer of 2-8 km thickness is present only below the Archean crust. The Proterozoic mafic lower crust might have been lost during continental collision by delamination or subduction, or thinned as a result of extensional collapse. Finally, the Cretaceous volcanics along the east coast are characterized by thin crust (30 km) and very large VP/VS ratios.

Published
2017
Full Text
View/download PDF

6. Shear velocity structure of the crust and upper mantle of Madagascar derived from surface wave tomography

Author

G. I. Aleqabi, Patrick J. Shore, Gérard Rambolamanana, Michael E. Wysession, Douglas A. Wiens, Tsiriandrimanana Rakotondraibe, Andrew A. Nyblade, E. J. Rindraharisaona, M. J. Pratt, Guilhem Barruol, Fenitra Andriampenomanana, Robert D. Tucker, Washington University in Saint Louis (WUSTL), Department of Geosciences, Pennsylvania State University (Penn State), Penn State System-Penn State System, Institut et Observatoire de Géophysique et Astronomie d'Antananarivo, Madagascar (IOGA), University of Maryland [College Park], University of Maryland System, Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), MACOMO project was provided by NSF award EAR-0838426DFG (Deutsche Forschungsgemeinschaft) grant SI1538/2-1, ANR-11-BS56-0013,RHUM-RUM,Imagerie mantellique du point chaud de La Réunion(2011), and Washington University in St Louis

Subjects
010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Volcanism, tomography, 010502 geochemistry & geophysics, ambient noise, 01 natural sciences, Geochemistry and Petrology, Asthenosphere, Madagascar, Earth and Planetary Sciences (miscellaneous), surface wave, 14. Life underwater, Shear velocity, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, ambient noise tomography, Crust, Sedimentary basin, Continental fragment, Geophysics, Space and Planetary Science, Magmatism, Intraplate earthquake, intraplate volcanism, Geology, Seismology
Abstract

International audience; The crust and upper mantle of the Madagascar continental fragment remained largely unexplored until a series of recent broadband seismic experiments. An island-wide deployment of broadband seismic instruments has allowed the first study of phase velocity variations, derived from surface waves, across the entire island. Late Cenozoic alkaline intraplate volcanism has occurred in three separate regions of Madagascar (north, central and southwest), with the north and central volcanism active until

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results