Aline Peltier; Sébastien Saur; Valérie Ballu; François Beauducel; Pierre Briole; Kristel Chanard; Denis Dausse; Jean-Bernard De Chabalier; Raphael Grandin; Perrine Rouffiac; Yann-Treden Tranchant; Maxime Bès de Berc; Simon Besançon; Patrice Boissier; Céleste Broucke; Christophe Brunet; Kevin Canjamalé; Erwan Carme; Philippe Catherine; Alison Colombain; Wayne Crawford; Romuald Daniel; Grégoire Dectot; Nicolas Desfete; Cécile Doubre; Tom Dumouch; Cyprien Griot; Marc Grunberg; Hélène Jund; Philippe Kowalski; Frédéric Lauret; Jacques Lebreton; Frédérick Pesqueira; Frédéric Tronel; Pierre Valty; Jérôme van der Woerd
Comptes Rendus. Géoscience, Volume 354 (2022) p. 171-193
Abstract : ... In May 2018, the Mayotte island, located in the Indian Ocean, was affected by an unprecedented seismic crisis, followed by anomalous on-land surface displacements in July 2018. Cumulatively from July 1, 2018 to December 31, 2021, the horizontal displacements were approximately 21 to 25 cm eastward, and subsidence was approximately 10 to 19 cm. ...
Lise Retailleau; Jean-Marie Saurel; Marine Laporte; Aude Lavayssière; Valérie Ferrazzini; Weiqiang Zhu; Gregory C. Beroza; Claudio Satriano; Jean-Christophe Komorowski; OVPF Team
Comptes Rendus. Géoscience, Volume 354 (2022) p. 153-170
Abstract : ... The seismic crisis that began in May, 2018 off the coast of Mayotte announced the onset of a volcanic eruption that started two months later 50 km southeast of the island. This seismicity has since been taken as an indicator of the volcanic and tectonic activity in the area. ...
Joan Andújar; Bruno Scaillet; Manuel Moreira; Ida Di Carlo; Anne Le Friant; Manon Bickert; Fabien Paquet; Stephan Jorry; Nathalie Feuillet
Comptes Rendus. Géoscience, Volume 354 (2022) p. 225-256
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. ...
Maud H. Devès; Sophie Moirand; Louise Le Vagueresse; Geoffrey Robert
Comptes Rendus. Géoscience, Volume 354 (2022) p. 391-415
Abstract : ... It shows how the voices of the main actors (the inhabitants, the administrative and scientific authorities) are put on the stage, conveying differing representations, differing forms of explanation and contributing to an effect of “enunciatory muddling”. It aims to provide food for thought for people called upon to intervene in the media, in Mayotte or elsewhere. ...
Agathe Roullé; Marie Baillet; Didier Bertil; Cécile Cornou
Comptes Rendus. Géoscience, Volume 354 (2022) p. 317-341
Abstract : ... Since the 2000s, local seismic hazard studies have shown that Mayotte Island presented superficial geological formations prone to lithological site effects. The seismic sequence initiated in May 2018 confirmed the importance of such effects, both in terms of intensity and spatial extension. ...
Nicolas Taillefer; Didier Bertil; Caterina Negulescu; Agathe Roullé; Christian Iasio; Samuel Auclair; Robin Quique
Comptes Rendus. Géoscience, Volume 354 (2022) p. 343-359
Abstract : ... A new marine volcano is erupting offshore Mayotte since May 2018, generating numerous earthquakes. The population felt many of them and the stronger shaking of the ongoing sequence caused slight damage to buildings. Historical records also confirm that damaging earthquakes had occurred in the past in this region. ...
Sara Bazin; Jean-Yves Royer; Flavie Dubost; Fabien Paquet; Benoît Loubrieu; Aude Lavayssière; Christine Deplus; Nathalie Feuillet; Éric Jacques; Emmanuel Rinnert; Isabelle Thinon; Élodie Lebas; Delphine Pierre; Lise Retailleau; Jean-Marie Saurel; Alexey Sukhovich; Robin Bonnet; the REVOSIMA group
Comptes Rendus. Géoscience, Volume 354 (2022) p. 257-273
Abstract : ... In 2019, a new underwater volcano was discovered at 3500 m below sea level (b.s.l.), 50 km east of Mayotte Island in the northern part of the Mozambique Channel. In January 2021, the submarine eruption was still going on and the volcanic activity, along with the intense seismicity that accompanies this crisis, was monitored by the recently created REVOSIMA (MAyotte VOlcano and Seismic Monitoring) network. ...
Marco Liuzzo; Andrea Di Muro; Andrea Luca Rizzo; Fausto Grassa; Massimo Coltorti; Magali Ader
Comptes Rendus. Géoscience, Volume 354 (2022) p. 275-298
Abstract : ... The archipelago results from intra-plate volcanism, the most recent eruptions having occurred on the youngest island of Grande Comore and on the oldest one of Mayotte. Since 2018, the eastern submarine flank of Mayotte has been the site of one of the largest recent eruptive events on Earth in terms of erupted lava volume. On land, the most recent volcanic activity occurred in Holocene on the eastern side of Mayotte, corresponding to the small Petite Terre Island, where two main and persistent gas seep areas are present (Airport Beach, namely BAS, and Dziani Dzaha intracrateric lake). ...
Charles Masquelet; Sylvie Leroy; Matthias Delescluse; Nicolas Chamot-Rooke; Isabelle Thinon; Anne Lemoine; Dieter Franke; Louise Watremez; Philippe Werner; Fabien Paquet; Carole Berthod; Victor Cabiativa Pico; Daniel Sauter
Comptes Rendus. Géoscience, Volume 354 (2022) p. 65-79
Abstract : ... The deepest tip of this volcanic layer lies below the top-Oligocene seismic horizon, indicating that the volcanism of Mayotte Island likely began around 26.5 Ma, earlier than previously assumed. ...
Pablo Poulain; Anne Le Friant; Rodrigo Pedreros; Anne Mangeney; Andrea G. Filippini; Gilles Grandjean; Anne Lemoine; Enrique D. Fernández-Nieto; Manuel J. Castro Díaz; Marc Peruzzetto
Comptes Rendus. Géoscience, Volume 354 (2022) p. 361-390
Abstract : ... Since May 2018, Mayotte Island has been experiencing seismo-volcanic activities that could trigger submarine landslides and, in turn, tsunamis. To address these hazards, we use the HySEA numerical model to simulate granular flow dynamics and the Boussinesq FUNWAVE-TVD numerical model to simulate wave propagation and subsequent inundations. ...
Anthony Dofal; Laurent Michon; Fabrice R. Fontaine; Elisa Rindraharisaona; Guilhem Barruol; Hrvoje Tkalčić
Comptes Rendus. Géoscience, Volume 354 (2022) p. 47-64
Abstract : ... Teleseismic receiver-functions and Rayleigh-wave dispersion curves are jointly inverted for quantifying $S$-wave velocity profiles beneath the active volcanic zone off Mayotte. We show that the lithosphere in the east-northeast quadrant is composed of four main layers, interpreted as the volcanic edifice, the crust with underplating, the lithospheric mantle, and the asthenosphere, the latter two presenting a main low-velocity zone. ...
Pierre Cadeau; Didier Jézéquel; Alexis Groleau; Andrea Di Muro; Magali Ader
Comptes Rendus. Géoscience, Volume 354 (2022) p. 299-316
Abstract : ... Since May 2018, an unexpected long and intense seismic crisis started offshore Mayotte (Indian Ocean, France). This ongoing seismic sequence is associated with the birth of a newly discovered submarine volcano 50 km east of Petite Terre. Here, we investigate the indirect impact of this crisis on the stability of an atypical ecosystem located in Mayotte, the Dziani Dzaha Lake. ...
Frédérique Rolandone; Jeffrey Poort; Charles Masquelet; Sylvie Leroy; Isabelle Thinon; Anne Lemoine; Fabien Paquet
Comptes Rendus. Géoscience, Volume 354 (2022) p. 35-46
Abstract : ... Three of the sites yield values of 42–47 $\text{mW/m}^2$, confirming low regional heat flow in this area. Our values are consistent with a Jurassic oceanic lithosphere around Mayotte, although the presence of very thin continental crust or continental fragments could also explain the observed heat flow. Our values do not support a regional thermal anomaly and so do not favor a hotspot model for Mayotte. ...
Didier Bertil; Nicolas Mercury; Cécile Doubre; Anne Lemoine; Jérôme Van der Woerd
Comptes Rendus. Géoscience, Volume 353 (2021) p. 211-235
Abstract : ... The Mayotte seismic sequence that started on 10 May 2018, with a main shock of magnitude Mw 5.9 on May 15, followed by a major offshore volcanic activity, raises several questions of seismo-volcanic hazards in the Comoros region. ...
Gérard Sarazin; Didier Jézéquel; Christophe Leboulanger; Eric Fouilland; Emilie Le Floc’h; Marc Bouvy; Emmanuelle Gérard; Hélène Agogué; Cécile Bernard; Mylène Hugoni; Vincent Grossi; Marc Troussellier; Magali Ader
Comptes Rendus. Géoscience, Volume 352 (2020) p. 559-577
Keywords : ... Thalassohaline lake, Endorheic ecosystem, Cyanobacteria, Methane emission, Biogeochemistry, Mayotte ...
Carole Berthod; Jean-Christophe Komorowski; Lucia Gurioli; Etienne Médard; Patrick Bachèlery; Pascale Besson; Pauline Verdurme; Oryaëlle Chevrel; Andrea Di Muro; Aline Peltier; Jean-Luc Devidal; Sophie Nowak; Isabelle Thinon; Pierre Burckel; Samia Hidalgo; Christine Deplus; Benoît Loubrieu; Delphine Pierre; Sylvain Bermell; Mathilde Pitel-Roudaut; Yvan Réaud; Sacha Fouchard; Manon Bickert; Anne Le Friant; Fabien Paquet; Nathalie Feuillet; Stephan L. Jorry; Yves Fouquet; Emmanuel Rinnert; Cécile Cathalot; Elodie Lebas
Comptes Rendus. Géoscience, Volume 354 (2022) p. 195-223
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. ...
Catalina Morales-Yáñez; Zacharie Duputel; Luis Rivera
Comptes Rendus. Géoscience, Volume 354 (2022) p. 137-152
Abstract : ... The archipelago of Comoros was generally considered a moderately seismic region. However, since May 2018, unusual seismicity has been observed off the east coast of Mayotte Island. Following this increase of seismic activity, oceanographic campaigns led to the discovery of a new submarine volcano, indicating that the observed seismicity had a volcanic origin. In this study, we estimate Centroid Moment Tensor (CMT) solutions of $M_w\ge 5$ earthquakes of this sequence using 3D Green’s functions and analyze their non-double-couple (non-DC) components. ...
Nicolas Mercury; Anne Lemoine; Cécile Doubre; Didier Bertil; Jérôme Van Der Woerd; Roser Hoste-Colomer; Jean Battaglia
Comptes Rendus. Géoscience, Volume 354 (2022) p. 105-136
Abstract : ... From 10 May 2018 to 1 November 2022 (time of writing), an unprecedented seismic activity is observed east of Mayotte Island (France), related to the largest submarine eruption ever recorded with offshore geophysical studies. Using signals from regional and local seismic stations, we build a comprehensive catalog of the local seismicity for the first ten months of the sequence. ...
Jérôme van der Woerd; Vincent Famin; Eric Humler
Comptes Rendus. Géoscience, Volume 354 (2022) p. 1-6
Full text : ...
The challenges posed by unexpected and poorly known natural hazard are manifold: scientific, technical and societal. Until 2018, Mayotte was classified as a zone of moderate seismicity and low probability of volcanism among French territories. The onset of the seismic crisis offshore Mayotte in May 2018, which appeared to be volcanic in the course of its discovery, has triggered an unprecedented mobilization of the French scientific, administrative and political communities (Figure 1). ...
Miki Mori
Comptes Rendus. Géoscience, Volume 354 (2022) p. 417-437
Abstract : ... The earthquake swarm that struck Mayotte in 2018 incited panic and various reactions among the local population. Because earthquakes are rare on the island, people were beside themselves, with many leaving their homes to wait out the night under the open air. ...