Search

Your search keyword '"Jorry, Stephan"' showing total 380 results
Start Over Author "Jorry, Stephan"
380 results on '"Jorry, Stephan"'

1. Experimental evidence for the shallow production of phonolitic magmas at Mayotte

Author

Andújar, Joan, Scaillet, Bruno, Moreira, Manuel, Di Carlo, Ida, Le Friant, Anne, Bickert, Manon, Paquet, Fabien, Jorry, Stephan, and Feuillet, Nathalie

Subjects
Mayotte, Phase equilibria, Phonolite, Iron-enrichment, Basanite, Geophysics. Cosmic physics, QC801-809, Chemistry, QD1-999, Geology, QE1-996.5
Abstract

Since May 2018 till the end of 2021, Mayotte island has been the locus of a major submarine volcanic eruption characterized by the offshore emission of more than 6.5 km$^{3}$ of basanitic magma. The eruption occurred along a WNW–ESE trending submarine ridge on the east flank of the island where, in addition, several seemingly recent phonolitic bodies were also identified close to the island. To define realistic scenarios of magma ascent and potentially predict the style of an upcoming event, it is crucial to have a precise understanding on the plumbing system operating below volcanoes. The putative relationships between basanites emitted by the new volcano and these recent phonolites have been experimentally explored by performing crystallization experiments on a representative basanite over a large range of pressures (up to 400 MPa). The results show that the crystallization of basanite at crustal levels (${\le }$12–15 km) yields a phonolitic residual liquid containing up to 3–4 wt% $\mathrm{H}_{2}\mathrm{O}$ after ${\ge }$65 wt% of an assemblage of olivine$+$plagioclase$+$amphibole$+$clinopyroxene$+$biotite$+$magnetite$+$ilmenite$+$apatite. The final iron content of the residual phonolitic liquids is strongly controlled by the depth/pressure of fractionation. Fe-rich phonolites from the submarine ridge are produced at 6–8 km depth, while a shallower differentiation (${\le }$4–5 km) results in the production of liquids with trachyte–benmoreite affinities. If the fractionation process occurs at depths higher than 8 km, the resulting phonolitic melts are progressively enriched in $\mathrm{SiO}_{2}$–$\mathrm{Al}_{2}\mathrm{O}_{3}$ but depleted in FeO*, ie unlike those erupted. We therefore conclude that phonolitic magma production and storage at Mayotte is a rather shallow process.

Published
2023
Full Text
View/download PDF

2. Volcano-tectonic structures of Mayotte’s upper submarine slope: insights from high-resolution bathymetry and in-situ imagery from a deep-towed camera

Author

Puzenat, Valentine, Feuillet, Nathalie, Komorowski, Jean-Christophe, Escartín, Javier, Deplus, Christine, Bachèlery, Patrick, Berthod, Carole, Gurioli, Lucia, Scalabrin, Carla, Cathalot, Cécile, Rinnert, Emmanuel, Loubrieu, Benoît, Pierre, Delphine, Pitel-Roudaut, Mathilde, Tanguy, Nina, Fouquet, Yves, Jorry, Stephan J., Lebas, Elodie, Paquet, Fabien, and Thinon, Isabelle

Subjects
Mayotte, Submarine volcanism, Geological mapping, High-resolution bathymetry, In-situ imagery, Geophysics. Cosmic physics, QC801-809, Chemistry, QD1-999, Geology, QE1-996.5
Abstract

Unlike subaerial volcanic activity, deep submarine eruptions are difficult to detect, observe and monitor. The objective of this paper is to describe a large and complex volcanic region, named the Horseshoe area, recently discovered at ${\sim }$1500 m below sea level on the eastern upper submarine slope of Mayotte Island. The area is crucial because, since 2018, it has experienced an exceptionally deep seismic activity associated with the ongoing submarine eruption that formed a new volcanic edifice, Fani Maoré, about 40 km to the east. We present the results of a multiscale study, based on high-resolution bathymetry and in-situ seafloor observations carried out with autonomous underwater vehicles (AUVs) and deep-towed camera systems. In-situ imagery provides ground-truth for the geological interpretation of seafloor textures mapped with the bathymetry. The combination of both datasets allows us to discuss the nature of the volcanic structures and to propose a relative chronology of previous eruptive events in the Horseshoe area. Based on our analyses, we propose the following chronology: (a) the emplacement of a large explosive volcanic cone, the Horseshoe edifice, (b) the later collapse of this edifice that resulted in the formation of an elongated, 2 km wide horseshoe-shaped depression, crosscutting older hummocky lava flows, (c) the development of an E–W eruptive fissure associated with numerous explosive craters, east of the Horseshoe edifice, and (d) late volcanism emanating from the rim of the horseshoe-shaped depression that fed elongated thin lava flows both towards and away from the depression. While all volcanic features mapped at the Horseshoe area were emplaced prior to the 2018 eruption, our study shows that this region has still been volcanically active in the recent past. Our results thus document a complex geological history at small spatial scales involved in the construction of major submarine edifices, and that are controlled by volcano-tectonic processes at larger scales.

Published
2022
Full Text
View/download PDF

3. Temporal magmatic evolution of the Fani Maoré submarine eruption 50 km east of Mayotte revealed by in situ sampling and petrological monitoring

Author

Berthod, Carole, Komorowski, Jean-Christophe, Gurioli, Lucia, Médard, Etienne, Bachèlery, Patrick, Besson, Pascale, Verdurme, Pauline, Chevrel, Oryaëlle, Di Muro, Andrea, Peltier, Aline, Devidal, Jean-Luc, Nowak, Sophie, Thinon, Isabelle, Burckel, Pierre, Hidalgo, Samia, Deplus, Christine, Loubrieu, Benoît, Pierre, Delphine, Bermell, Sylvain, Pitel-Roudaut, Mathilde, Réaud, Yvan, Fouchard, Sacha, Bickert, Manon, Le Friant, Anne, Paquet, Fabien, Feuillet, Nathalie, Jorry, Stephan L., Fouquet, Yves, Rinnert, Emmanuel, Cathalot, Cécile, and Lebas, Elodie

Subjects
Fractional crystallization, Mixing, Mayotte, Submarine eruption, Dredging, Petrological monitoring, Magmatic system, Geophysics. Cosmic physics, QC801-809, Chemistry, QD1-999, Geology, QE1-996.5
Abstract

The “Fani Maoré” eruption off the coasts of Mayotte has been intensively monitored by applying methods similar to those used for subaerial eruptions. Repeated high-resolution bathymetric surveys and dredging, coupled with petrological analyses of time-constrained samples, allowed tracking the evolution of magma over the whole submarine eruptive sequence. Indeed, after one year of direct ascent (Phase 1), basanitic magma switched to a different pathway that sampled a tephri-phonolitic subcrustal reservoir (Phase 2). Later, the magma pathway shifted again in the crust resulting in a new eruption site located 6 km northwest of the main edifice (Phase 3). The petrological signature of lava flows reveals both an evolution by fractional crystallization and syn-eruptive mixing with a tephri-phonolitic magma.We demonstrate that high-flux eruption of large volumes of basanitic magma from a deep-seated reservoir can interact with shallower reservoirs and remobilize eruptible magma. This has significant hazards implications with respect to the capacity of such large eruptions to reactivate shallow-seated inactive reservoirs from a transcrustal magmatic system that could be located potentially at a distance from the high-flux eruptive site.

Published
2022
Full Text
View/download PDF

4. Volcanism and tectonics unveiled in the Comoros Archipelago between Africa and Madagascar

Author

Thinon, Isabelle, Lemoine, Anne, Leroy, Sylvie, Paquet, Fabien, Berthod, Carole, Zaragosi, Sébastien, Famin, Vincent, Feuillet, Nathalie, Boymond, Pierre, Masquelet, Charles, Mercury, Nicolas, Rusquet, Anaïs, Scalabrin, Carla, Van der Woerd, Jérôme, Bernard, Julien, Bignon, Julie, Clouard, Valérie, Doubre, Cécile, Jacques, Eric, Jorry, Stephan J., Rolandone, Frédérique, Chamot-Rooke, Nicolas, Delescluse, Matthias, Franke, Dieter, Watremez, Louise, Bachèlery, Patrick, Michon, Laurent, Sauter, Daniel, Bujan, Stéphane, Canva, Albane, Dassie, Emilie, Roche, Vincent, Ali, Said, Sitti Allaouia, Abdoul Hamid, Deplus, Christine, Rad, Setareh, and Sadeski, Ludivine

Subjects
Volcanic province, Active tectonics, Incipient plate boundary, Bathymetry, Backscatter, Northern Mozambique Channel, Comoros Archipelago, Geophysics. Cosmic physics, QC801-809, Chemistry, QD1-999, Geology, QE1-996.5
Abstract

Geophysical and geological data from the North Mozambique Channel acquired during the 2020–2021 SISMAORE oceanographic cruise reveal a corridor of recent volcanic and tectonic features 200 km wide and 600 km long within and north of Comoros Archipelago. Here we identify and describe two major submarine tectono-volcanic fields: the N’Droundé province oriented N160°E north of Grande-Comore Island, and the Mwezi province oriented N130°E north of Anjouan and Mayotte Islands. The presence of popping basaltic rocks sampled in the Mwezi province suggests post-Pleistocene volcanic activity. The geometry and distribution of recent structures observed on the seafloor are consistent with a current regional dextral transtensional context. Their orientations change progressively from west to east (${\sim }$N160°E, ${\sim }$N130°E, ${\sim }$EW). The volcanism in the western part appears to be influenced by the pre-existing structural fabric of the Mesozoic crust. The 200 km-wide and 600 km-long tectono-volcanic corridor underlines the incipient Somalia–Lwandle dextral lithospheric plate boundary between the East-African Rift System and Madagascar.

Published
2022
Full Text
View/download PDF

10. Birth of a large volcanic edifice offshore Mayotte via lithosphere-scale dyke intrusion

Author

Feuillet, Nathalie, Jorry, Stephan, Crawford, Wayne C., Deplus, Christine, Thinon, Isabelle, Jacques, Eric, Saurel, Jean Marie, Lemoine, Anne, Paquet, Fabien, Satriano, Claudio, Aiken, Chastity, Foix, Océane, Kowalski, Philippe, Laurent, Angèle, Rinnert, Emmanuel, Cathalot, Cécile, Donval, Jean-Pierre, Guyader, Vivien, Gaillot, Arnaud, Scalabrin, Carla, Moreira, Manuel, Peltier, Aline, Beauducel, François, Grandin, Raphaël, Ballu, Valérie, Daniel, Romuald, Pelleau, Pascal, Gomez, Jérémy, Besançon, Simon, Geli, Louis, Bernard, Pascal, Bachelery, Patrick, Fouquet, Yves, Bertil, Didier, Lemarchand, Arnaud, and Van der Woerd, Jérome

Published
2021
Full Text
View/download PDF

14. Multiscale spatial patterns and environmental drivers of seamount and island slope megafaunal assemblages along the Mozambique channel

Author

Hanafi Portier, Melissa, Samadi, Sarah, Corbari, Laure, Boulard, Marion, Miramontes, Elda, Penven, Pierrick, Leroy, Boris, Napoléon, Thibault, Jorry, Stephan, Olu - Le Roy, Karine, Hanafi Portier, Melissa, Samadi, Sarah, Corbari, Laure, Boulard, Marion, Miramontes, Elda, Penven, Pierrick, Leroy, Boris, Napoléon, Thibault, Jorry, Stephan, and Olu - Le Roy, Karine

Abstract

Seamounts are vulnerable ecosystems targeted by fishing and potentially by future mineral exploitation. Their abundance, widespread distribution, and heterogeneity of faunal and abiotic components require integrated studies at multiscale to describe spatial patterns and identify environmental drivers needed by conservation plans. There is also a lack of knowledge on seamount benthic ecosystems in some regions, such as the Indian Ocean. These gaps, in the context of Marine Protected Areas establishment in the region, have motivated the present study focusing on the Mozambique Channel Eparses islands and flat top seamounts, along a 10-degree latitude gradient. These structures are characterized by complex volcanic and carbonate geomorphologies at multiscale and are distributed along a highly dynamic turbulent ocean circulation area with large anticyclonic eddies. For the first time, we analysed, from seabed image transects obtained by towed-camera on four seamounts, and two volcanic islands - Bassas da India and Mayotte - external slopes, and from multiscale environmental data, how benthic communities respond to this high habitat heterogeneity at regional, and local scales. This study reveals high discrepancies of benthic megafauna richness, density, and beta diversity between seamounts and between slopes of the same islands. Moreover, at similar latitude, seamounts display higher densities than island slopes. The highest densities found on a seamount of the Glorieuses archipelago are explained by strong currents and flat homogeneous geomorphology. Except on this seamount, the beta diversity is high, despite the quite limited depth range explored (84–734 m) and is the highest on island slopes and Hall Bank, driven by the diversity and hardness of the substrate. Beta diversity is mainly due to taxa turnover, with high contribution of the habitat-forming sponges and cnidarians, together with a few mobile taxa. We identified from biogeographic network analysis 12 dominan

Published
2024
Full Text
View/download PDF

16. Decadal timescale evolution of coral islands: insights from Lakshadweep Archipelago.

Author

Menon, Shradha, Khanna, Pankaj, Misra, Saikat Kumar, and Jorry, Stephan J.

Subjects
CORAL reefs & islands, GLOBAL warming, SOUTHERN oscillation, OCEAN acidification, SEA level
Abstract

Low–lying coral islands are susceptible to rising sea levels and climate change, posing risks to island habitability over the next century. The decadal timescale evolution of the islands can provide an understanding of the governing controls of change and island response. This study investigates variations in the shoreline morphology of the Lakshadweep coral islands (Northern Indian Ocean/Arabian Sea) using satellite datasets (2003–2022; CNES/Airbus;0.3m – 0.7m resolution) and sedimentological data. Of the thirty islands (ten inhabited), six islands (Bangaram, Thinnakara, Suheli, Minicoy, Androth and Bitra) have been studied. Most of these islands are less than 1 km² in size except Androth and Minicoy (>4 km² ). While the data is discontinuous for the islands due to cloud obscuring, the shoreline morphology depicts variations for all the islands’ studied, irrespective of habitation and size. Larger islands have undergone consistent erosion since 2007 (total land loss is approximately 3 - 5% cumulatively). Smaller islands have undergone lateral migration, with sediment erosion usually along the southern edge and sediment migration and accumulation northwards, however, overall, their size remains consistently stable. The migration of sediments is observed only from 2007–2017, which coincides with severe El–Nino Southern Oscillation (ENSO) and low amplitude positive Indian Ocean Dipole (IOD) events. Furthermore, sedimentological analysis along Bangaram’s (small island) accreting margin reveals unconsolidated bio-detrital grainstones with predominant sand-sized fractions (2 – 0.25mm). Corals (43%), molluscs (33%), forams (13%), and algae (8%) are the major sediment producers (with 3% unidentified bioclasts). The ongoing climate warming and ocean acidification will influence the carbonate sediment budget in addition to the changing hydrodynamics owing to monsoons, cyclones, and coupled ocean-atmospheric regional phenomenon, altering the sediment production, transport and accumulation on these islands. Furthermore, rising sea levels and consequent erosion by wave action might lead to rapid drowning in the next few centuries. Our study identifies the current status of the island size variability in the Lakshadweep Archipelago and how site-specific and global factors influence them, thus providing insights into assessing the habitability within these low-lying coral islands. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

20. Mantle xenolith-bearing phonolites and basanites feed the active volcanic ridge of Mayotte (Comoros archipelago, SW Indian Ocean)

Author

Berthod, Carole, Médard, Etienne, Di Muro, Andrea, Hassen Ali, Théo, Gurioli, Lucia, Chauvel, Catherine, Komorowski, Jean-Christophe, Bachèlery, Patrick, Peltier, Aline, Benbakkar, Mhammed, Devidal, Jean-Luc, Besson, Pascale, Le Friant, Anne, Deplus, Christine, Nowak, Sophie, Thinon, Isabelle, Burckel, Pierre, Hidalgo, Samia, Feuillet, Nathalie, Jorry, Stephan, and Fouquet, Yves

Published
2021
Full Text
View/download PDF

27. A two-million-year-long hydroclimatic context for hominin evolution in southeastern Africa

Author

Caley, Thibaut, Extier, Thomas, Collins, James A., Schefuß, Enno, Dupont, Lydie, Malaizé, Bruno, Rossignol, Linda, Souron, Antoine, McClymont, Erin L., Jimenez-Espejo, Francisco J., García-Comas, Carmen, Eynaud, Frédérique, Martinez, Philippe, Roche, Didier M., Jorry, Stephan J., Charlier, Karine, Wary, Mélanie, Gourves, Pierre-Yves, Billy, Isabelle, and Giraudeau, Jacques

Published
2018
Full Text
View/download PDF

28. Sea-level fluctuations control the distribution of highly liquefaction-prone layers on volcanic-carbonate slopes

Author

Sultan, Nabil, Jouet, Gwenael, Riboulot, Vincent, Terzariol, Marco, Garziglia, Sebastien, Cattaneo, Antonio, Giraudeau, J., Jorry, Stephan, Sultan, Nabil, Jouet, Gwenael, Riboulot, Vincent, Terzariol, Marco, Garziglia, Sebastien, Cattaneo, Antonio, Giraudeau, J., and Jorry, Stephan

Abstract

Understanding and quantifying the hazards related to earthquake-induced submarine liquefaction and landslides are particularly significant offshore of tropical volcanic-carbonate islands, where carbonate production competes with volcanism to create highly contrasted lithological successions. To improve the detection of liquefaction-prone layers, we analyzed physical properties and mineralogy and performed 70 dynamic triaxial tests on 25 sediment cores offshore of the eastern side of Mayotte (Comoros archipelago in the western Indian Ocean) in an area that has experienced significant seismicity since 2018. We found that the main parameter controlling the liquefaction potential offshore of Mayotte is the presence of low-density layers with high calcite content accumulating along the slope during lowstands. This phasing with sea-level fluctuations implies a significant recurrent geohazard for tropical volcanic-carbonate islands worldwide. Furthermore, the relationship we found between the cyclic resistance of sediment and its density and magnetic susceptibility represents a time-effective approach for identifying the hazards related to earthquake-induced liquefaction.

Published
2023
Full Text
View/download PDF

32. Volcanism and tectonics unveiled in the Comoros Archipelago between Africa and Madagascar

Author

Thinon, Isabelle, primary, Lemoine, Anne, additional, Leroy, Sylvie, additional, Paquet, Fabien, additional, Berthod, Carole, additional, Zaragosi, Sébastien, additional, Famin, Vincent, additional, Feuillet, Nathalie, additional, Boymond, Pierre, additional, Masquelet, Charles, additional, Mercury, Nicolas, additional, Rusquet, Anaïs, additional, Scalabrin, Carla, additional, Van der Woerd, Jérôme, additional, Bernard, Julien, additional, Bignon, Julie, additional, Clouard, Valérie, additional, Doubre, Cécile, additional, Jacques, Eric, additional, Jorry, Stephan J., additional, Rolandone, Frédérique, additional, Chamot-Rooke, Nicolas, additional, Delescluse, Matthias, additional, Franke, Dieter, additional, Watremez, Louise, additional, Bachèlery, Patrick, additional, Michon, Laurent, additional, Sauter, Daniel, additional, Bujan, Stéphane, additional, Canva, Albane, additional, Dassie, Emilie, additional, Roche, Vincent, additional, Ali, Said, additional, Sitti Allaouia, Abdoul Hamid, additional, Deplus, Christine, additional, Rad, Setareh, additional, and Sadeski, Ludivine, additional

Published
2023
Full Text
View/download PDF

33. Volcano-tectonic structures of Mayotte’s upper submarine slope: insights from high-resolution bathymetry and in-situ imagery from a deep-towed camera

Author

Puzenat, Valentine, primary, Feuillet, Nathalie, additional, Komorowski, Jean-Christophe, additional, Escartín, Javier, additional, Deplus, Christine, additional, Bachèlery, Patrick, additional, Berthod, Carole, additional, Gurioli, Lucia, additional, Scalabrin, Carla, additional, Cathalot, Cécile, additional, Rinnert, Emmanuel, additional, Loubrieu, Benoît, additional, Pierre, Delphine, additional, Pitel-Roudaut, Mathilde, additional, Tanguy, Nina, additional, Fouquet, Yves, additional, Jorry, Stephan J., additional, Lebas, Elodie, additional, Paquet, Fabien, additional, and Thinon, Isabelle, additional

Published
2023
Full Text
View/download PDF

34. Temporal magmatic evolution of the Fani Maoré submarine eruption 50 km east of Mayotte revealed by in situ sampling and petrological monitoring

Author

Berthod, Carole, primary, Komorowski, Jean-Christophe, additional, Gurioli, Lucia, additional, Médard, Etienne, additional, Bachèlery, Patrick, additional, Besson, Pascale, additional, Verdurme, Pauline, additional, Chevrel, Oryaëlle, additional, Di Muro, Andrea, additional, Peltier, Aline, additional, Devidal, Jean-Luc, additional, Nowak, Sophie, additional, Thinon, Isabelle, additional, Burckel, Pierre, additional, Hidalgo, Samia, additional, Deplus, Christine, additional, Loubrieu, Benoît, additional, Pierre, Delphine, additional, Bermell, Sylvain, additional, Pitel-Roudaut, Mathilde, additional, Réaud, Yvan, additional, Fouchard, Sacha, additional, Bickert, Manon, additional, Le Friant, Anne, additional, Paquet, Fabien, additional, Feuillet, Nathalie, additional, Jorry, Stephan L., additional, Fouquet, Yves, additional, Rinnert, Emmanuel, additional, Cathalot, Cécile, additional, and Lebas, Elodie, additional

Published
2023
Full Text
View/download PDF

35. The Fe-rich, mildly alkaline magma series of Mayotte’s Eastern submarine volcanic chain (Mayotte, France, Western Indian Ocean)

Author

Chaudron Vrignaud, Emma, primary, Lacombe, Tristan, additional, Médard, Etienne, additional, Berthod, Carole, additional, Bachèlery, Patrick, additional, Komorowski, Jean-Christophe, additional, Gurioli, Lucia, additional, Verdurme, Pauline, additional, Besson, Pascale, additional, LeBas, Elodie, additional, Thinon, Isabelle, additional, Jorry, Stephan, additional, Paquet, Fabien, additional, Rinnert, Emmanuel, additional, Feuillet, Nathalie, additional, Yves, Fouquet, additional, Cathalot, Cécile, additional, and Le Friant, Anne, additional

Published
2023
Full Text
View/download PDF

38. Mayotte seismic crisis: building knowledge in near real-time by combining land and ocean-bottom seismometers, first results

Author

Saurel, Jean-marie, Jacques, Eric, Aiken, Chastity, Lemoine, Anne, Retailleau, Lise, Lavayssière, Aude, Foix, Oceane, Dofal, Anthony, Laurent, Angèle, Mercury, Nicolas, Crawford, Wayne, Lemarchand, Arnaud, Daniel, Romuald, Pelleau, Pascal, De Berc, Maxime Bès, Dectot, Grégoire, Bertil, Didier, Roullé, Agathe, Broucke, Céleste, Colombain, Alison, Jund, Hélène, Besançon, Simon, Guyavarch, Pierre, Kowalski, Philippe, Roudaut, Mickael, Apprioual, Ronan, Battaglia, Jean, Bodihar, Soumya, Boissier, Patrice, Bouin, Marie Paule, Brunet, Christophe, Canjamale, Kévin, Catherine, Philippe, Desfete, Nicolas, Doubre, Cécile, Dretzen, Rémi, Dumouche, Tom, Fernagu, Philippe, Ferrazzini, Valérie, Fontaine, Fabrice, Gaillot, Arnaud, Géli, Louis, Griot, Cyprien, Grunberg, Marc, Guzel, Emre Can, Hoste-colomer, Roser, Lambotte, Sophie, Lauret, Frédéric, Léger, Félix, Maros, Emmanuel, Peltier, Aline, Vergne, Jérôme, Satriano, Claudio, Tronel, Frédéric, Van Der Woerd, Jérôme, Fouquet, Yves, Jorry, Stephan, Rinnert, Emmanuel, Thinon, Isabelle, Feuillet, Nathalie, Saurel, Jean-marie, Jacques, Eric, Aiken, Chastity, Lemoine, Anne, Retailleau, Lise, Lavayssière, Aude, Foix, Oceane, Dofal, Anthony, Laurent, Angèle, Mercury, Nicolas, Crawford, Wayne, Lemarchand, Arnaud, Daniel, Romuald, Pelleau, Pascal, De Berc, Maxime Bès, Dectot, Grégoire, Bertil, Didier, Roullé, Agathe, Broucke, Céleste, Colombain, Alison, Jund, Hélène, Besançon, Simon, Guyavarch, Pierre, Kowalski, Philippe, Roudaut, Mickael, Apprioual, Ronan, Battaglia, Jean, Bodihar, Soumya, Boissier, Patrice, Bouin, Marie Paule, Brunet, Christophe, Canjamale, Kévin, Catherine, Philippe, Desfete, Nicolas, Doubre, Cécile, Dretzen, Rémi, Dumouche, Tom, Fernagu, Philippe, Ferrazzini, Valérie, Fontaine, Fabrice, Gaillot, Arnaud, Géli, Louis, Griot, Cyprien, Grunberg, Marc, Guzel, Emre Can, Hoste-colomer, Roser, Lambotte, Sophie, Lauret, Frédéric, Léger, Félix, Maros, Emmanuel, Peltier, Aline, Vergne, Jérôme, Satriano, Claudio, Tronel, Frédéric, Van Der Woerd, Jérôme, Fouquet, Yves, Jorry, Stephan, Rinnert, Emmanuel, Thinon, Isabelle, and Feuillet, Nathalie

Abstract

The brutal onset of seismicity offshore Mayotte island North of the Mozambique Channel, Indian Ocean, that occurred in May 2018 caught the population, authorities, and scientific community off guard. Around 20 potentially felt earthquakes were recorded in the first 5 days, up to magnitude Mw 5.9. The scientific community had little pre-existing knowledge of the seismic activity in the region due to poor seismic network coverage. During 2018 and 2019, the MAYOBS/REVOSIMA seismology group was progressively built between four French research institutions to improve instrumentation and data sets to monitor what we know now as an on-going exceptional sub-marine basaltic eruption. After the addition of 3 medium-band stations on Mayotte island and 1 on Grande Glorieuse island in early 2019, the data recovered from the Ocean Bottom Seismometers were regularly processed by the group to improve the location of the earthquakes detected daily by the land network. We first built a new local 1D velocity model and established specific data processing procedures. The local 1.66 low VP/VS ratio we estimated is compatible with a volcanic island context. We manually picked about 125,000 P and S phases on land and sea bottom stations to locate more than 5,000 events between February 2019 and May 2020. The earthquakes outline two separate seismic clusters offshore that we named Proximal and Distal. The Proximal cluster, located 10km offshore Mayotte eastern coastlines, is 20 to 50 km deep and has a cylindrical shape. The Distal cluster start 5 km to the east of the Proximal cluster and extends below Mayotte's new volcanic edifice, from 50 km up to 25 km depth. The two clusters appear seismically separated, however our dataset is insufficient to firmly demonstrate this.

Published
2022
Full Text
View/download PDF

39. Evidence expérimentale de la production de magmas phonolitiques à faible profondeur à Mayotte

Author

Andújar, Joan, Scaillet, Bruno, Moreira, Manuel, Di Carlo, Ida, Le Friant, Anne, Bickert, Manon, Paquet, Fabien, Jorry, Stephan, Feuillet, Nathalie, Andújar, Joan, Scaillet, Bruno, Moreira, Manuel, Di Carlo, Ida, Le Friant, Anne, Bickert, Manon, Paquet, Fabien, Jorry, Stephan, and Feuillet, Nathalie

Abstract

Since May 2018 till the end of 2021, Mayotte island has been the locus of a major submarine volcanic eruption characterized by the offshore emission of more than 6.5 km of basanitic magma. The eruption occurred along a WNW–ESE trending submarine ridge on the east flank of the island where, in addition, several seemingly recent phonolitic bodies were also identified close to the island. To define realistic scenarios of magma ascent and potentially predict the style of an upcoming event, it is crucial to have a precise understanding on the plumbing system operating below volcanoes. The putative relationships between basanites emitted by the new volcano and these recent phonolites have been experimentally explored by performing crystallization experiments on a representative basanite over a large range of pressures (up to 400 MPa). The results show that the crystallization of basanite at crustal levels (12–15 km) yields a phonolitic residual liquid containing up to 3–4 wt% after 65 wt% of an assemblage of olivineplagioclaseamphiboleclinopyroxenebiotitemagnetiteilmeniteapatite. The final iron content of the residual phonolitic liquids is strongly controlled by the depth/pressure of fractionation. Fe-rich phonolites from the submarine ridge are produced at 6–8 km depth, while a shallower differentiation (4–5 km) results in the production of liquids with trachyte–benmoreite affinities. If the fractionation process occurs at depths higher than 8 km, the resulting phonolitic melts are progressively enriched in – but depleted in FeO*, ie unlike those erupted. We therefore conclude that phonolitic magma production and storage at Mayotte is a rather shallow process., Depuis mai 2018 et jusqu’à la fin de l’année 2021, l’île de Mayotte a été le scenario d’une éruption volcanique sous-marine majeure caractérisée par l’émission en mer de plus de 6,5 km de magma basanitique. L’éruption s’est produite le long d’une ride sous-marine orientée ONO–ESE sur le flanc est de l’île où, entre autre, plusieurs corps phonolitiques d’ aspect récent ont également été identifiés à proximité de l’île. Pour définir des scénarios réalistes d’ascension du magma et potentiellement prévoir le style d’un événement à venir, il est crucial d’avoir une compréhension précise du système de plomberie magmatique opérant sous les volcans. Les relations génétiques potentielles entre les basanites émises par le nouveau volcan et ces phonolites récentes ont été explorées expérimentalement en effectuant des expériences de cristallisation sur une basanite représentative, et ce sur une large gamme de pressions (jusqu’à 400 MPa). Les résultats montrent que la cristallisation de la basanite à des profondeurs crustales (12–15 km) produit un liquide résiduel phonolitique contenant jusqu’à 3–4 % en poids (pd.%) de HO, après la précipitation d’au moins 65 pd.% d’un assemblage d’olivineplagioclaseamphiboleclinopyroxènebiotitemagnétiteilméniteapatite. La teneur finale en fer des liquides phonolitiques résiduels est fortement contrôlée par la profondeur/pression de cristallisation. Les phonolites riches en fer de la dorsale sous-marine sont produites à 6–8 km de profondeur, tandis qu’une différenciation moins profonde (4–5 km) entraîne la production de liquides à affinités trachyte–benmoreite. Si le processus de fractionnement se produit à des profondeurs supérieures à 8 km, les liquides phonolitiques résultants sont progressivement enrichis en SiO–AlO mais appauvris en FeO*, c’est-à-dire différents des phonolites naturelles. Nous concluons donc que la production et le stockage de magma phonolitique à Mayotte est un processus plutôt superficiel.

Published
2022
Full Text
View/download PDF

40. First characterization of the volcanism in the southern Mozambique Channel: Geomorphological and structural analyses

Author

Berthod, C., Bachèlery, P., Jorry, Stephan, Pitel-roudaut, Mathilde, Ruffet, G., Revillon, Sidonie, Courgeon, S., Doucelance, R., Berthod, C., Bachèlery, P., Jorry, Stephan, Pitel-roudaut, Mathilde, Ruffet, G., Revillon, Sidonie, Courgeon, S., and Doucelance, R.

Abstract

The southern part of the Mozambique Channel is characterized by a cluster of isolated seamounts, including the Bassas da India atoll and Europa Island, ranging in latitude from 20°S to 22°S and from 38° to 40° in longitude, and located at the Rovuma-Lwandle plate boundary. Only Cenozoic carbonate platforms have previously been studied in this region, with very little work done on the volcanic history. We confirm here the volcanic nature of the basement of the Bassa da India/Europa complex by providing important constraints on the setting of this hitherto poorly understood volcanism. Recent bathymetric surveys and dredging operations allowed us to map and date these seamounts, comprising, from west to east, the Hall Bank, the Jaguar Bank, Bassas da India, Ptolemee, and Europa. In addition, we discovered, to the south of Bassas da India, two large new polygenetic volcanic edifices, Pamela Seamount 1 (PS1) and Pamela Seamount 2 (PS2), showing heights and diameters of up to 900 m and 13 km, respectively. Mapping and statistical analysis carried out revealed that the volcanic structures of the Bassas da India/Europa complex are organized along two main alignments with different stages of development: (i) a NE-SW volcanic alignment characterized by volcanic ridges up to 700 m in height, comprising small individual volcanic cones; and (ii) a NW-SE volcanic alignment in which many large and well-developed individual volcanic cones can be found. From this distribution of the volcanism, we suggest that the large volcanic edifices of the Bassas da India/Europa complex were fed by long-lived magma systems, repeatedly supplied from deep magma reservoirs through a significant network of dykes and faults, with lateral injections of magma guided by a dense network of faults allowing magma to reach the surface along rift-zones. 40Ar/39Ar dating confirms that the volcanism covers a period from the Oligo-Miocene to the Pleistocene, and probably extends to the present day. The two volc

Published
2022
Full Text
View/download PDF

45. Evolution du mont sous-marin des Glorieuses (Sud-Ouest Océan Indien) et du bassin profond Somali depuis le Crétacé

Author

Leroux, Estelle, Counts, John, Jorry, Stephan, Jouet, Gwenael, Révillon, Sidonie, Boudagher-Fadel, Marcelle, Courgeon, Simon, Berthod, Carole, Ruffet, Gilles, Bachelery, Patrick, Grenard-Grand, Elise, United States Geological Survey (USGS), Géosciences Rennes (GR), 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), Laboratoire Magmas et Volcans (LMV-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-SPIN-Centre National de la Recherche Scientifique (CNRS)-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)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-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), Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), SGF, CNRS, Laboratoire de Géologie de Lyon ou l’étude de la Terre, des planètes et de l’environnement, and Sciencesconf.org, CCSD

Subjects
soulèvement), marin des Glorieuses, plate, volcanisme, stratigraphie sismique, 40Ar/39Ar, [SDU] Sciences of the Universe [physics], tectonique, forme carbonatée, [SDU]Sciences of the Universe [physics], mont sous, Bassin Somali, ComputingMilieux_MISCELLANEOUS, mouvements verticaux (subsidence
Abstract

International audience

Published
2021

46. Discovery of recent volcanic and tectonic provinces along the Comoros archipelago (North Mozambique Channel) ─ Preliminary results of the SISMAORE oceanographic cruise (ANR-COYOTES project)

Author

Thinon, Isabelle, Lemoine, Anne, Leroy, Sylvie, Ali, Said, Berthod, Carole, Bernard, Julien, Bignon, Julie, Boymond, Pierre, Bujan, Stéphane, Canva, Albane, Chamot-Rooke, Nicolas, Clouard, Valérie, Dassie, Emilie, Delescluse, Matthias, Doubre, Cécile, Famin, Vincent, Feuillet, Nathalie, Franke, Dieter, Jacques, Eric, Jorry, Stephan, Masquelet, Charles, Mercury, Nicolas, Paquet, Fabien, Roche, Vincent, Rolandone, Frédérique, Rusquet, Anais, Sadeski, Ludivine, Scalabrin, Carla, Abdoulhamid, Sitti Allaouia, Woerd, Jerome van Der, Watremez, Louise, Zaragosi, Sébastien, Michon, Laurent, Bachelery, Patrick, Deplus, Christine, Sauter, Daniel, Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Institut des Sciences de la Terre de Paris (iSTeP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université des Comores, 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), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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), 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]), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Géosciences Environnement Toulouse (GET), 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)-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)-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), Université Paris sciences et lettres (PSL), Institut Terre Environnement Strasbourg (ITES), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université de La Réunion - Faculté des Sciences et Technologies (FST), Université de La Réunion (UR), Faculté des sciences de la vie (Université de Strasbourg), Ecole et Observatoire des Sciences de la Terre (EOST), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), ANR-19-CE31-0018, SGF, CNRS, Laboratoire de Géologie de Lyon ou l’étude de la Terre, des planètes et de l’environnement, ANR-19-CE31-0018,COYOTES,COmores & maYotte : vOlcanisme, TEctonique et Sismicité(2019), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS), Ingénierie des Matériaux Polymères (IMP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), 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 normale supérieure - Paris (ENS Paris), Institut national des sciences de l'Univers (INSU - CNRS)-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 Fédérale Toulouse Midi-Pyrénées-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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Université de Strasbourg - UFR Mathématique et Informatique (UNISTRA UFR MI), Université de Strasbourg (UNISTRA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut national des sciences de l'Univers (INSU - CNRS), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (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), and Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
Comoros archipelago, Mayotte, inheritance, ANR COYOTES, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mozambique Channel, Recent tectonic and volcanic deformation, SISMAORE
Abstract

International audience; A new geophysical and geological dataset, acquired during the SISMAORE oceanographic campaign (2020-2021), reveals a recent tectonic and volcanic deformation distributed over 130km in the abyssal plain that permit to unravel the unconstrained lithospheric plate boundaries between Lwandle and Somalia blocks and the controversial origin of the Comoros Archipelago.Two recent submarine volcanic and tectonic provinces of 5000km2 , with a large number of varied volcanic structures and faults, are unveiled: the N160° N'Droundé (north of GrandeComore) and the N130° Mwezi provinces (north of Anjouan/Mayotte). Dredged Mwezi rocks suggest a recent gas-rich volcanic activity. It is also identified a recent N130° trending volcanic structures (cones, lava flows, eruptive fissures) between Anjouan and Mayotte in agreement with the presence of shallow earthquakes, and also recent lava flows on the southern flanks of the Grande Comore and Moheli. Southwards, recent sedimentation is important with no volcanism and deformation. A consistent sedimentary thickness covers the flanks of Mayotte and Anjouan and the presence of large areas of submarine instability at the foot and on the slope of the islands is confirmed.These first observations suggest a transtensional deformation, accommodated by dextral strike-slip motion, strongly influenced by pre-existing structuration of the Mesozoic oceanic crust and by the East Africa Rift system. The 130km wide zone of intraplate deformationcharacterizes an immature lithospheric plate boundary of the north Lwandle block.

Published
2021

48. The 2018-ongoing Mayotte submarine eruption: Magma migration imaged by petrological monitoring

Author

Berthod, Carole, primary, Médard, Etienne, additional, Bachèlery, Patrick, additional, Gurioli, Lucia, additional, Di Muro, Andrea, additional, Peltier, Aline, additional, Komorowski, Jean-Christophe, additional, Benbakkar, Mhammed, additional, Devidal, Jean-Luc, additional, Langlade, Jessica, additional, Besson, Pascale, additional, Boudon, Georges, additional, Rose-Koga, Estelle, additional, Deplus, Christine, additional, Le Friant, Anne, additional, Bickert, Manon, additional, Nowak, Sophie, additional, Thinon, Isabelle, additional, Burckel, Pierre, additional, Hidalgo, Samia, additional, Kaliwoda, Melanie, additional, Jorry, Stephan J., additional, Fouquet, Yves, additional, and Feuillet, Nathalie, additional

Published
2021
Full Text
View/download PDF

49. Mayotte seismic crisis: building knowledge in near real-time by combining land and ocean-bottom seismometers, first results

Author

Saurel, Jean-Marie, primary, Jacques, Eric, additional, Aiken, Chastity, additional, Lemoine, Anne, additional, Retailleau, Lise, additional, Lavayssière, Aude, additional, Foix, Océane, additional, Dofal, Anthony, additional, Laurent, Angèle, additional, Mercury, Nicolas, additional, Crawford, Wayne, additional, Lemarchand, Arnaud, additional, Daniel, Romuald, additional, Pelleau, Pascal, additional, Bès de Berc, Maxime, additional, Dectot, Grégoire, additional, Bertil, Didier, additional, Roullé, Agathe, additional, Broucke, Céleste, additional, Colombain, Alison, additional, Jund, Hélène, additional, Besançon, Simon, additional, Guyavarch, Pierre, additional, Kowalski, Philippe, additional, Roudaut, Mickaël, additional, Apprioual, Ronan, additional, Battaglia, Jean, additional, Bodihar, Soumya, additional, Boissier, Patrice, additional, Bouin, Marie Paule, additional, Brunet, Christophe, additional, Canjamale, Kévin, additional, Catherine, Philippe, additional, Desfete, Nicolas, additional, Doubre, Cécile, additional, Dretzen, Rémi, additional, Dumouche, Tom, additional, Fernagu, Philippe, additional, Ferrazzini, Valérie, additional, Fontaine, Fabrice R, additional, Gaillot, Arnaud, additional, Géli, Louis, additional, Griot, Cyprien, additional, Grunberg, Marc, additional, Guzel, Emre Can, additional, Hoste-Colomer, Roser, additional, Lambotte, Sophie, additional, Lauret, Frédéric, additional, Léger, Félix, additional, Maros, Emmanuel, additional, Peltier, Aline, additional, Vergne, Jérôme, additional, Satriano, Claudio, additional, Tronel, Frédéric, additional, Van der Woerd, Jérôme, additional, Fouquet, Yves, additional, Jorry, Stephan J, additional, Rinnert, Emmanuel, additional, Thinon, Isabelle, additional, and Feuillet, Nathalie, additional

Published
2021
Full Text
View/download PDF

50. Non-linear forcing of climate on denudation in the Alps over the last 75 ka

Author

Mariotti , Apolline, Blard , Pierre-Henri, Charreau , Julien, Toucanne , Samuel, Jorry , Stephan, Molliex , Stéphane, and ASTER , Team

Abstract

Reconstruction of denudation rates through time is an important task to quantify and understand the impact of climate on landscape evolution. Cosmogenic nuclides have been widely used as a tool to infer denudation rates at the watershed scale from both river sediments and past stratigraphic records. Here, we analyze the in-situ 10Be cosmogenic concentration over the last 75 ka in sediments cores that were collected offshore the Var River (Western Mediterranean Sea). We present 26 10Be paleo denudation rates ranging from 0.15 ± 0.01 and 1.26 ± 0.16 mm yr−1. At the exception of the LGM period, the 10Be paleo denudation rates are similar to these of today in the Var (0.24 ± 0.04 mm yr−1). However, during the LGM, paleo denudation rates were 2 to 3 times higher than today, suggesting that glaciers may have played a role. To investigate this sharp increase in denudation rates, we use a mass balance approach to differentiate the glacial from the fluvial component of denudation rates. The resulting average glacial erosion rate during the LGM is 1.5 (+0.9 / -1.0) mm yr−1, roughly four times above the value of 0.4 (+0.4 / -0.5) mm yr−1 obtained during MIS 3-4 (29 - 71 ka) Our data suggest that climatic variations may only strongly affect denudation beyond a certain threshold, probably controlled by glacier dynamics, the duration of glacial advances, and temperature-driven processes such as frost cracking. Our study indicates that the denudation response to Quaternary glaciations is complex and nonlinear in glaciated areas.

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results