Ground deformation monitoring of the eruption offshore Mayotte

Peltier, Aline; Saur, Sébastien; Ballu, Valérie; Beauducel, François; Briole, Pierre; Chanard, Kristel; Dausse, Denis; Chabalier, Jean-Bernard de; Grandin, R.; Rouffiac, Perrine; Tranchant, Yann-Treden; Berc, Maxime Bès de; Besançon, Simon; Boissier, Patrice; Broucke, Céleste; Brunet, Christophe; Canjamale, Kévin; Carme, Erwan; Catherine, Philippe; Colombain, Alison; Crawford, Wayne; Daniel, Romuald; Dectot, Grégoire; Desfete, Nicolas; Doubre, Cécile; Dumouch, Tom; Griot, Cyprien; Grunberg, Marc; Jund, Hélène; Kowalski, Philippe; Lauret, Fréderic; Lebreton, Jacques; Pesqueira, Frédérick; Tronel, Frédéric; Valty, P.; Woerd, J. van der

doi:10.5802/crgeos.176

Cited by 6 publications

(5 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This 820 m tall, 5.0 ± 0.3 km 3 volcanic edifice, now officially called "Fani Maoré", built in one year of eruption [Rinnert et al, 2019, is interpreted as evidence of the damping of a deep and exceptionally large reservoir. This is supported by the large GPS surface displacements, implying a barycenter of deformation located 40 km eastward of Mayotte and 30 km deep [Lemoine et al, 2020a; see also Peltier et al, 2022].…”

Section: The Recent Mayotte Seismo-volcanic Sequencementioning

confidence: 71%

Onset of a submarine eruption east of Mayotte, Comoros archipelago: the first ten months seismicity of the seismo-volcanic sequence (2018–2019)

Mercury¹,

Lemoine²,

Doubre³

et al. 2023

Comptes Rendus. Géoscience

Self Cite

View full text Add to dashboard Cite

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. This catalog includes a total of 2874 events of magnitude (Mlv) ranging from 2.4 to 6.0, with 77% of them relocated using a double difference location procedure. The hypocentral locations over this period are highly dependent on the small seismic network available. Therefore we compare the locations of later events using a similar network and those estimated from a local ocean bottom seismometer (OBS) network installed since March 2019. Based on the time space evolution and characteristics of the seismicity, five distinct phases can be identified, corresponding to the successive activation of two deep seismic swarms, related to the lithospheric-scale magma ascent up to the seafloor, along with progressive deepening of the seismicity interpreted as decompression of a 40 km deep reservoir.

show abstract

Section: The Recent Mayotte Seismo-volcanic Sequencementioning

confidence: 71%

Onset of a submarine eruption east of Mayotte, Comoros archipelago: the first ten months seismicity of the seismo-volcanic sequence (2018–2019)

Mercury¹,

Lemoine²,

Doubre³

et al. 2023

Comptes Rendus. Géoscience

Self Cite

View full text Add to dashboard Cite

show abstract

“…Very-long-period seismic signals were also detected [Cesca et al, 2020, Lemoine et al, 2020, and could be generated by the resonance of a fluid-filled cavity [Feuillet et al, 2021. At the same time, GNSS stations recorded significant ground deformation of the island, with ∼20 cm of subsidence, and a horizontal displacement of ∼15 cm eastward [Lemoine et al, 2020, REVOSIMA, 2022, Peltier et al, 2022. It was later proposed that the intense seismicity and significant surface deformation were linked to the drainage of a deep magma reservoir through dykes, leading to a deep submarine eruption [Cesca et al, 2020, Lemoine et al, 2020.…”

Section: Geological Settingmentioning

confidence: 96%

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

Puzenat¹,

Feuillet²,

Komorowski³

et al. 2023

Comptes Rendus. Géoscience

View full text Add to dashboard Cite

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 ∼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 highresolution 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.

show abstract

“…If we now consider that the impulsive events date the emplacement of the lava and that they occurred in the 41 days between the first and last swarms, the effusion rate can be estimated to 14 m 3 /s. Using continuous GNSS data, Peltier et al [33] had estimated the effusion rate by modeling the observed surface deformation and the associated volume variation over time. They computed that the source flow rate decreased from 357 ± 60 m 3 /s in December 2018 to 5 ± 7 m 3 /s in 2021.…”

Section: Evolution In Space and Time Of The Lava Flowsmentioning

confidence: 99%

“…Associated with an important tilt (10-19 cm of subsidence and 21-25 cm eastward displacement) [29,30], this seismicity has been linked with intense magmatic activity at depth, which later gave birth to a new underwater volcanic edifice ∼50 km offshore, named Fani Maoré (Figure 1). Comprehensive seismic catalogs [31,32], ground deformation studies [33], and extensive petrological and geochemical analyses [34,35] have helped interpreting the eruption processes of Fani Maoré as well as previous submarine eruptions in the region. Moreover, several lava flows around the new volcanic structure have been evidenced by repeated bathymetric surveys every 6 months to a year.…”

Section: Introductionmentioning

confidence: 99%

Hydroacoustic Monitoring of Mayotte Submarine Volcano during Its Eruptive Phase

Lavayssière,

Bazin,

Royer

2024

Geosciences

View full text Add to dashboard Cite

Submarine volcanoes are more challenging to monitor than subaerial volcanoes. Yet, the large eruption of the Hunga Tonga-Hunga Ha’apai volcano in the Tonga archipelago in 2022 was a reminder of their hazardous nature and hence demonstrated the need to study them. In October 2020, four autonomous hydrophones were moored in the sound fixing and ranging channel 50 km offshore Mayotte Island, in the North Mozambique Channel, to monitor the Fani Maoré 2018–2020 submarine eruption. Between their deployment and July 2022, this network of hydrophones, named MAHY, recorded sounds generated by the recent volcanic activity, along with earthquakes, submarine landslides, marine mammals calls, and marine traffic. Among the sounds generated by the volcanic activity, impulsive signals have been evidenced and interpreted as proxy for lava flow emplacements. The characteristics and the spatio-temporal evolution of these hydroacoustic signals allowed the estimation of effusion and flow rates, key parameters for volcano monitoring. These sounds are related to the non-explosive quenching of pillow lavas due to the rapid heat transfer between hot lava and cold seawater, with this process releasing an energy equivalent to an airgun source as used for active seismic exploration. Volcano observatories could hence use autonomous hydrophones in the water column to detect and monitor active submarine eruptions in the absence of regular on-site seafloor survey.

show abstract

Ground deformation monitoring of the eruption offshore Mayotte

Abstract: Ground deformation monitoring of the eruption offshore MayotteSuivi des déformations liées à l'éruption au large de Mayotte

Cited by 6 publications

References 39 publications

Onset of a submarine eruption east of Mayotte, Comoros archipelago: the first ten months seismicity of the seismo-volcanic sequence (2018–2019)

Onset of a submarine eruption east of Mayotte, Comoros archipelago: the first ten months seismicity of the seismo-volcanic sequence (2018–2019)

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

Hydroacoustic Monitoring of Mayotte Submarine Volcano during Its Eruptive Phase

Contact Info

Product

Resources

About