Search

Your search keyword '"Deroussi, Sébastien"' showing total 25 results
Start Over Author "Deroussi, Sébastien"
25 results on '"Deroussi, Sébastien"'

1. A multi-decadal view of the heat and mass budget of a volcano in unrest: La Soufri\`ere de Guadeloupe (French West Indies)

Author

Jessop, David E., Moune, Séverine, Moretti, Roberto, Gibert, Dominique, Komorowski, Jean-Christophe, Robert, Vincent, Heap, Michael J., Bosson, Alexis, Bonifacie, Magali, Deroussi, Sébastien, Dessert, Céline, Rosas-Carbajal, Marina, Lemarchand, Arnaud, and Burtin, Arnaud

Subjects
Physics - Geophysics
Abstract

Particularly in the presence of a hydrothermal system, many volcanoes output large quantities of heat through the transport of water from deep within the edifice to the surface. Thus, heat flux is a prime tool for evaluating volcanic activity and unrest. We review the volcanic unrest at La Soufri\`ere de Guadeloupe (French West Indies) using an airborne thermal camera survey, and in-situ measurements of temperature and flow rate through temperature probes, Pitot-tube and MultiGAS measurements. We deduce mass and heat fluxes for the fumarolic, ground and thermal spring outputs and follow these over a period spanning 2000--2020. Our results are compared with published data and we performed a retrospective analysis of the temporal variations in heat flux over this period using the literature data. We find that the heat emitted by the volcano is 36.5 +/- 7.9 MW, of which the fumarolic heat flux is dominant at 28.3 +/- 6.8 MW. Given a total heated area of 26780 m2, this equates to a heat flux density of 627 +/- 94 W/m2, which is amongst the highest established for worldwide volcanoes with hydrothermal systems, particularly for dome volcanoes. A major change at La Soufri\`ere de Guadeloupe, however, is the development of a widespread region of ground heating at the summit where heat output has increased from 0.2 +/- 0.1 MW in 2010 to 5.7 +/- 0.9 MW in 2020. This change is concurrent with accelerating unrest at the volcano, and the emergence of two new high-flux fumaroles in recent years. Our findings highlight the importance of continued and enhanced surveillance and research strategies at La Soufri\`ere de Guadeloupe, the results of which can be used to better understand hydrothermal volcanism the world over.

Published
2020
Full Text
View/download PDF

2. Three-dimensional density structure of La Soufrie\`ere de Guadeloupe lava dome from simultaneous muon radiographies and gravity data

Author

Rosas-Carbajal, Marina, Jourde, Kevin, Marteau, Jacques, Deroussi, Sébastien, Komorowski, Jean-Christophe, and Gibert, Dominique

Subjects
Physics - Geophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

Muon imaging has recently emerged as a powerful method to complement standard geophysical tools in the understanding of the Earth's subsurface. Muon measurements can yield a radiography of the average density along the muon path, allowing to image large volumes of a geological body from a single observation point. Here we jointly invert muon data from three simultaneous telescope acquisitions together with gravity data to estimate the three-dimensional density structure of the La Soufri\`ere de Guadeloupe lava Dome. Our unique dataset allows us to achieve an unprecedented spatial resolution with this novel technique. The retrieved density model reveals an extensive, low-density anomaly where the most active part of the volcanic hydrothermal system is located, supporting previous studies that indicate this region as the most likely to be involved in a partial edifice collapse., Comment: 4 figures, 7 pages

Published
2017
Full Text
View/download PDF

3. The 2018 unrest phase at La Soufrière of Guadeloupe (French West Indies) andesitic volcano: Scrutiny of a failed but prodromal phreatic eruption

Author

Moretti, Roberto, Komorowski, Jean-Christophe, Ucciani, Guillaume, Moune, Séverine, Jessop, David, de Chabalier, Jean-Bernard, Beauducel, François, Bonifacie, Magali, Burtin, Arnaud, Vallée, Martin, Deroussi, Sebastien, Robert, Vincent, Gibert, Dominique, Didier, Tristan, Kitou, Thierry, Feuillet, Nathalie, Allard, Patrick, Tamburello, Giancarlo, Shreve, Tara, Saurel, Jean-Marie, Lemarchand, Arnaud, Rosas-Carbajal, Marina, Agrinier, Pierre, Le Friant, Anne, and Chaussidon, Marc

Published
2020
Full Text
View/download PDF

7. Observation of the Dynamics of Hydrothermal Activity in La Soufrière of Guadeloupe Volcano with Joint Muography, Gravimetry, Electrical Resistivity Tomography, Seismic and Temperature Monitoring

Author

Gibert, Dominique, primary, de Bremond d'Ars, Jean, additional, Carlus, Bruno, additional, Deroussi, Sébastien, additional, Ianigro, Jean‐Christophe, additional, Jessop, David E., additional, Jourde, Kevin, additional, Kergosien, Bruno, additional, Le Gonidec, Yves, additional, Lesparre, Nolwenn, additional, Marteau, Jacques, additional, Moretti, Roberto, additional, Nicollin, Florence, additional, and Rosas‐Carbajal, Marina, additional

Published
2022
Full Text
View/download PDF

8. Optical long range instruments for high resolution monitoring of geohazard in harsh environment

Author

Bernard, Pascal, Plantier, Guy, Ménard, Philippe, Feuilloy, Mathieu, Feron, Romain, Guitton, Damien, Savaton, Guillaume, Deroussi, Sébastien, Hello, Yann, Nercessian, Alexandre, Moretti, Roberto, Boudin, Frédérick, Lemarchand, Arnaud, Métaxian, Jean-Philippe, Longo, Roberto, Ripepe, Maurizio, Pommeau, Thierry, Stutzmann, Eléonore, Trabattoni, Alister, Léger, Félix, 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), École supérieure d'électronique de l'ouest [Angers] (ESEO), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Résif, 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), ESEO-GSII (GSII), ESEO-Tech, Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO)-Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO), Laboratoire d'Acoustique de l'Université du Mans (LAUM), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), and Università degli Studi di Firenze = University of Florence (UniFI)

Subjects
Sismologie, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], RESIF, Seismology
Abstract

International audience; In many areas with high telluric hazard, our understanding of the seismogenic and mechanical processes is limited by the difficulty or impossibility to deploy arrays of high performance seismometers or of other geophsyical sensors, due to high cost and/or difficulty of the installation and maintenance. This led us to develope several optical instruments: the idea was to separate, by a long optical fiber, the robust mechanical part of the sensor from the opto-electronic part, which interrogates the sensor and measures its internal deformation with Fabry-Perot (FP) interferometry. Our IPGP-ESEO team has thus constructed innovative optical seismometers and strainmeters, complemented by borehole and long base optical tiltmeters from Geoscience Montpellier and ENS. Here we present the ESEO-IPGP instruments, and their successful installation in the field: one seismometer at the top of La Soufrière volcano (1.5 km long fiber), 10/2019 (ANR HIPERSIS ); one ocean-bottom seismometer offshore Les Saintes, 06/2021 (FIBROSAINTES, Interreg Caraïbe PREST) (5 km long fiber buried by a plow GEOAZUR); and one strainmeter on the Stromboli volcano (09/2021).

Published
2021

11. Muographic long-term monitoring of the Soufrière of Guadeloupe with a system of coupled muon detection systems

Author

Marteau, Jacques, Rosas-Carbajal, Marina, tramontini, matias, Zyserman, Fabio, De Bremond D'Ars, Jean, Le Gonidec, Yves, Carlus, Bruno, Ianigro, Jean-Christophe, Deroussi, Sébastien, Gibert, Dominique, Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Universidad Nacional de la Plata [Argentine] (UNLP), Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Observatoire Volcanologique et sismologique de la Soufrière de Guadeloupe, American Geophysical Union, Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Abstract

International audience; We present novel developments in muography methods to combine continuous measurementsperformed by 2 independant muon detectors around the dome of an active volcano, the Soufrièreof Guadeloupe. The aim is to reach the best possible performances in the continuous monitoringof its hydrothermal system spatio-temporal dynamics.Volcanic hydrothermal systems give rise to unpredictable hazards such as hydrothermal explo-sions, partial edifice collapse, mudflows and sudden emission of toxic gases. Characterizing the dy-namics of these systems and constraining the models by real-time data is thus critical for develop-ing efficient risk assessment.Within the DIAPHANE project, funded by the french National Research Agency (ANR), 6 muontelescopes have been deployed around the dome since 2015 and acquire muon data continuouslywith a large duty cycle. In this work we show the results obtained with a set of more than 1.5years of continuous measurements acquired with 2 muon detectors scanning different zones of thedome with large overlapping volumes. Characterizing the time changes in the outgoing muon fluxin different regions allows us to study the density changes caused by steam formation, condensa-tion, water infiltration and storage.The details of the analysis is presented : region definition through common geological structures,principal component analysis of the temporal series, determination of the changes in opacity im-plied by the muon-flux changes observed. This strategy allows us to spatially constrain the three-dimensional location of the coherent density changes and to improve the quantification of the as-sociated mass changes. The obtained results on the active zone of the Soufrière of Guadeloupe’sSouth crater are presented in details.

Published
2019

14. Long-term, coupled muon measurements to track density changes at La Soufrière de Guadeloupe volcano

Author

Rosas-Carbajal, Marina, Marteau, Jacques, tramontini, matias, Zyzerman, fabio, De Bremond D'Ars, Jean, Le Gonidec, Yves, Carlus, Bruno, Ianigro, Jean-Christophe, Deroussi, Sébastien, Gibert, Dominique, 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), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional de la Plata [Argentine] (UNLP), Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Observatoire Volcanologique et sismologique de la Soufrière de Guadeloupe, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)

Subjects
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Physics::Geophysics
Abstract

International audience; Volcanic hydrothermal systems give rise to unpredictable hazards such as hydrothermal explosions, partial edifice collapse, mudflows and sudden emission of toxic gases. Characterizing the dynamics of these systems is thus critical for developing efficient risk assessment.Here we present the use of continuous muon measurements at La Soufrière de Guadeloupe volcano as a novel methodology to characterize the spatio-temporal dynamics of its hydrothermal system. Six muon telescopes acquire data continuously around the lava dome since 2015. In this work a set of more than 1.5 years of continuous measurements acquired with two muon detectors is analyzed. The two telescopes scan two different zones of the dome with large overlapping volumes. Characterizing the time changes in the outgoing muon flux in different regions allows us to study the density changes caused by steam formation, condensation, water infiltration and storage. First, we define these regions according to the different geological structures in the volcano presenting characteristic behaviors: active/non-active fumarolic zones, and shallow/deeper sections of the system. We then perform a principal component analysis of the temporal series to identify which lines-of-sight of the two telescopes present coherent temporal variations. Finally, we make use of calibrated static muon radiographies to determine the changes in opacity implied by the muon-flux changes observed. This strategy allows us to spatially constrain the three-dimensional location of the coherent density changes and to improve the quantification of the associated mass changes.

Published
2018

15. Characterizing the dynamics of hydrothermal systems with muon tomography: the case of La Soufrière de Guadeloupe

Author

Rosas-Carbajal, Marina, Marteau, Jacques, Tramontini, Matias, de Bremond d'Ars, Jean, Le Gonidec, Yves, Carlus, Bruno, Ianigro, Jean-Christophe, Deroussi, Sébastien, Komorowski, Jean-Christophe, Gibert, Dominique, Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Universidad Nacional de la Plata [Argentine] (UNLP), Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Observatoire Volcanologique et sismologique de la Soufrière de Guadeloupe, Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Physics::Geophysics
Abstract

International audience; Muon imaging has recently emerged as a powerful method to complement standard geophysical tools in the study of the Earth’s subsurface. Muon measurements yield a radiography of the average density along the muon path, allowing to image large volumes of a geological body from a single observation point. Long-term measurements allow to infer density changes by tracking the associated variations in the muon flux. In the context of volcanic hydrothermal systems, this approach helps to characterize zones of steam formation, condensation, water infiltration and storage. We present results of imaging the La Soufrière de Guadeloupe dome and shallow active hydrothermal system with a network of muon telescopes viewing the dome from different positions around its base. First, we jointly invert the muon radiographies of the different telescopes with gravity data to obtain a three-dimensional density model of the lava dome. The model reveals an extended low density region where the hydrothermal system is most active. We then analyze the dynamics of the hydrothermal system from long-term measurements (more than 2 years of almost non-interrupted acquisition) with 5 simultaneous muon telescopes. We identify a periodicity of ~1-2 months in the density increase/decrease in the most active zones below fumaroles and acid boiling ponds. Our simultaneous-muon telescope strategy provides constraints on the three-dimensional location of the density changes and an improved quantification of the associated mass flux changes. We compare the temporal trends acquired by the different muon telescopes to time-series of rainfall on the summit recharge area as well as to ground temperature profiles in the vicinity of thermal anomalies and high-discharge summit fumaroles.

Published
2017

16. 3-D Resistivity Structure of La Soufrière Volcano (Guadeloupe): New Insights into the Hydrothermal System and Associated Hazards

Author

Rosas-Carbajal, Marina, Nicollin, Florence, Komorowski, Jean-Christophe, Gibert, Dominique, Deroussi, Sébastien, Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Observatoire Volcanologique et sismologique de la Soufrière de Guadeloupe, American Geophysical Union, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Abstract

International audience; The 3-D electrical resistivity model of the dome of La Soufrière of Guadeloupe volcano was obtained by inverting more than 23000 electrical resistivity tomography (ERT) and mise-a-la-masse data points. Data acquisition involved 2-D and 3-D protocols, including several pairs of injection electrodes located on opposite sides of the volcano. For the mise-a-la-masse measurements, the contact with a conductive mass was achieved by immersing one of the current electrodes in the Tarissan acid pond (~25 Siemens/m) located in the volcano's summit. The 3-D inversion was performed using a deterministic smoothness-constrained least-squares algorithm with unstructured grid modeling to accurately account for topography. Resistivity contrasts of more than 4 orders of magnitude are observed. A thick and high-angle conductive structure is located in the volcano's southern flank. It extends from the Tarissan Crater's acid pond on the summit to a hot spring region located close to the dome’s southern base. This suggests that a large hydrothermal reservoir is located below the southern base of the dome, and connected to the acid pond of the summit's main crater. Therefore, the steep southern flanks of the volcano could be resting on a low-strength, high-angle discontinuity saturated with circulating and possibly pressurized hydrothermal fluids. This could favor partial edifice collapse and lateral directed explosions as shown recurrently in the volcano's history. The resistivity model also reveals smaller hydrothermal reservoirs in the south-east and northern flanks that are linked to the main historical eruptive fractures and to ancient collapse structures such as the Cratère Amic structure. We discuss the main resistivity structures in relation with the geometry of observed faults, historical eruptive fractures, the dynamics of the near surface hydrothermal system manifestations on the dome and the potential implications for future hazards scenarios .

Published
2015

18. Géologie des Marquises : des volcans boucliers intra-océaniques effondrés issus d’un point chaud atypique

Author

Maury, René C., Guille, Gérard, Guillou, Hervé, Chauvel, Catherine, Legendre, Christelle, Rossi, Philippe, Blais, Sylvain, Pallares, Carlos, Deroussi, Sébastien, Anne-Marie, Marabal, Université européenne de Bretagne - European University of Brittany (UEB), Domaines Océaniques (LDO), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-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), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), 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), Paléocéanographie (PALEOCEAN), 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), Géochimie, Institut des Sciences de la Terre (ISTerre), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), ccgm, CCGM, Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-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), 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), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Basalte, Polynésie, Hotspot, Marquesas Archipelago, Marquises, Point chaud, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Polynesia, Bouclier (volcan), Caldeira, Basalt, Shield (volcano), Caldera
Abstract

National audience; The Marquesas archipelago is the northernmost of thefour Neogene-Quaternary linear intraplate chains of FrenchPolynesia. We present the first detailed geological maps ofits eight main volcanic islands (Eiao, Nuku Hiva, Ua Huka,Ua Pou, Hiva Oa, Tahuata, Motane, Fatu Hiva). The islandages decrease from northwest (5.5 Ma at Eiao) towardssoutheast (1.1 Ma at Fatu Hiva). The Marquesas shieldvolcanoes experienced important sector collapse eventslinked to caldera formation, which led to the sinking of half ormore of their initial shields. Most islands are made up of anouter remnant of such a shield, in the caldera of which liesan inner, younger and smaller post-shield volcano. The totalvolume of Marquesas volcanic edifices (42,500 km3 abovethe -3 000 m isobath) corresponds to a rather low magmaticproduction (7,700 km3 per million years, i.e. less than 4 % ofthat of Big Island, Hawaii). Magmas uprising from theMarquesas hotspot reach the surface episodically, hence theuncertainties regarding its location, generally thought to beclose to the Marquesas Fracture Zone. These magmasderive from low to moderate melting rates of a highlyheterogeneous (at a 10 km scale) “weak” mantle plumewhich includes two adjacent filaments of slightly differentisotopic compositions. These produced two rows of islandslabelled the northeastern Ua Huka group and thesouthwestern Fatu Hiva group, respectively. The Marquesasvolcanic successions depart from the Hawaiian model, astholeiitic magmas are not restricted to the shield stage, nor alkali basaltic/basanitic magmas to the post-shield stage.These two types are thought to derive from relativelydepleted (peridotitic) and enriched (pyroxenitic) componentsof the plume, respectively.; L’archipel des Marquises comporte huit îlesprincipales (Eiao, Nuku Hiva, Ua Huka, Ua Pou, Hiva Oa,Tahuata, Motane, Fatu Hiva), dont nous présentons lespremières cartes géologiques détaillées. L’âge de cesîles diminue du Nord-Ouest (5,5 Ma à Eiao) au Sud-Est(1,1 Ma à Fatu Hiva). Les volcans boucliers marquisiensdiffèrent considérablement de leurs équivalentshawaiiens. Ils ont fréquemment subi des effondrementssectoriels, responsables de la disparition en mer de lamoitié, voire davantage des boucliers initiaux, dans lacaldeira desquels est apparu un volcan interne plusrécent et plus petit. Le volume total des édificesvolcaniques (42 500 km3 au-dessus de l’isobathe -3 000 m) correspond à une production magmatiquefaible (7 700 km3/Ma, soit moins de 4 % de celle deHawaii). Les magmas issus du point chaud marquisienn’arrivent en surface qu’épisodiquement, d’où lesincertitudes quant à sa position précise au voisinage dela zone de fracture des Marquises. Ils dérivent de taux defusion faibles à modérés d’un panache de manteau trèshétérogène, comportant deux filaments accolés decompositions isotopiques différentes, qui ont produit aucours du temps deux alignements d’îles (groupe de UaHuka au Nord-Est, groupe de Fatu Hiva au Sud-Ouest).

Published
2014

20. Relative campaign during the International Comparison of Absolute Gravimeters ICAG-2005 and the strategy of data treatment combined with the absolute results

Author

Jiang, Zhiheng, Vitushkin, Leonid, Becker, Matthias, Francis, Olivier, Jousset, Philippe, Ferry, Matthieu, Dupont, François, Deroussi, Sébastien, Métivier, Laurent, Pajot, Gwendaline, and others

Subjects
Earth sciences & physical geography [G02] [Physical, chemical, mathematical & earth Sciences], Sciences de la terre & géographie physique [G02] [Physique, chimie, mathématiques & sciences de la terre]
Published
2007

21. Evaluating surface and subsurface water storage variations at small time and space scales from relative gravity measurements in semiarid Niger

Author

Pfeffer, Julia, primary, Champollion, Cédric, additional, Favreau, Guillaume, additional, Cappelaere, Bernard, additional, Hinderer, Jacques, additional, Boucher, Marie, additional, Nazoumou, Yahaya, additional, Oï, Monique, additional, Mouyen, Maxime, additional, Henri, Christopher, additional, Le Moigne, Nicolas, additional, Deroussi, Sébastien, additional, Demarty, Jérôme, additional, Boulain, Nicolas, additional, Benarrosh, Nathalie, additional, and Robert, Olivier, additional

Published
2013
Full Text
View/download PDF

22. A seafloor experiment to monitor vertical deformation at the Lucky Strike volcano, Mid-Atlantic Ridge

Author

Ballu, Valérie, primary, Ammann, Jérome, additional, Pot, Olivier, additional, de Viron, Olivier, additional, Sasagawa, Glenn S., additional, Reverdin, Gilles, additional, Bouin, Marie-Noelle, additional, Cannat, Mathilde, additional, Deplus, Christine, additional, Deroussi, Sébastien, additional, Maia, Marcia, additional, and Diament, Michel, additional

Published
2008
Full Text
View/download PDF

24. Spatio-Temporal Relationships between Fumarolic Activity, Hydrothermal Fluid Circulation and Geophysical Signals at an Arc Volcano in Degassing Unrest: La Soufrière of Guadeloupe (French West Indies).

Author

Tamburello, Giancarlo, Moune, Séverine, Allard, Patrick, Venugopal, Swetha, Robert, Vincent, Rosas-Carbajal, Marina, Deroussi, Sébastien, Kitou, Gaëtan-Thierry, Didier, Tristan, Komorowski, Jean-Christophe, Beauducel, François, De Chabalier, Jean-Bernard, Le Marchand, Arnaud, Le Friant, Anne, Bonifacie, Magali, Dessert, Céline, and Moretti, Roberto

Subjects
VOLCANOES, SOIL air, LAVA domes, ATOMIC mass, VOLCANIC gases, SPATIO-temporal variation, ELECTRICAL resistivity
Abstract

Over the past two decades, La Soufrière volcano in Guadeloupe has displayed a growing degassing unrest whose actual source mechanism still remains unclear. Based on new measurements of the chemistry and mass flux of fumarolic gas emissions from the volcano, here we reveal spatio-temporal variations in the degassing features that closely relate to the 3D underground circulation of fumarolic fluids, as imaged by electrical resistivity tomography, and to geodetic-seismic signals recorded over the past two decades. Discrete monthly surveys of gas plumes from the various vents on La Soufrière lava dome, performed with portable MultiGAS analyzers, reveal important differences in the chemical proportions and fluxes of H2O, CO2, H2S, SO2 and H2, which depend on the vent location with respect to the underground circulation of fluids. In particular, the main central vents, though directly connected to the volcano conduit and preferentially surveyed in past decades, display much higher CO2/SO2 and H2S/SO2 ratios than peripheral gas emissions, reflecting greater SO2 scrubbing in the boiling hydrothermal water at 80–100 m depth. Gas fluxes demonstrate an increased bulk degassing of the volcano over the past 10 years, but also a recent spatial shift in fumarolic degassing intensity from the center of the lava dome towards its SE–NE sector and the Breislack fracture. Such a spatial shift is in agreement with both extensometric and seismic evidence of fault widening in this sector due to slow gravitational sliding of the southern dome sector. Our study thus provides an improved framework to monitor and interpret the evolution of gas emissions from La Soufrière in the future and to better forecast hazards from this dangerous andesitic volcano. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results