Volcanic eruptions shape Earth’s surface and provide a window into deep Earth processes. How the primary asthenospheric melts form, pond and ascend through the lithosphere is, however, still poorly understood. Since 10 May 2018, magmatic activity has occurred offshore eastern Mayotte (North Mozambique channel), associated with large surface displacements, very-low-frequency earthquakes and exceptionally deep earthquake swarms. Here we present geophysical and marine data from the MAYOBS1 cruise, which reveal that by May 2019, this activity formed an 820-m-tall, ~5 km³ volcanic edifice on the seafloor. This is the largest active submarine eruption ever documented. Seismic and deformation data indicate that deep (>55 km depth) magma reservoirs were rapidly drained through dykes that intruded the entire lithosphere and that pre-existing subvertical faults in the mantle were reactivated beneath an ancient caldera structure. We locate the new volcanic edifice at the tip of a 50-km-long ridge composed of many other recent edifices and lava flows. This volcanic ridge is an extensional feature inside a wide transtensional boundary that transfers strain between the East African and Madagascar rifts. We propose that the massive eruption originated from hot asthenosphere at the base of a thick, old, damaged lithosphere.
This is a preview of subscription content, access via your institution
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Get just this article for as long as you need it
Prices may be subject to local taxes which are calculated during checkout
The authors declare that most of the data supporting the findings of this study are available within the paper and its Supplementary Information files. GNSS data are available on the website (http://mayotte.gnss.fr) and can be downloaded from ftp://rgpdata.ign.fr/pub/gnss_mayotte/. Ship-borne geophysical data from the MAYOBS1 cruise can be obtained through the French national oceanographic data centre SISMER (http://en.data.ifremer.fr/SISMER, https://doi.org/10.17600/18001217), but restrictions apply to the availability of these data. The compilations of older bathymetric and topographic data are available on the SHOM website (http://www.shom.fr, https://doi.org/10.17183/S201406900). Rock samples are referenced at https://wwz.ifremer.fr/echantillons/Echantillons/Carte#/map (https://campagnes.flotteoceanographique.fr/prl?id=BFBGX-134187). Samples are accessible on site at IFREMER, Plouzané, France. Map were created using Globe software (https://doi.org/10.17882/70460)75, ArcGIS software by Esri (https://www.arcgis.com/index.html), Generic Mapping Tools86, Adobe illustrator (https://www.adobe.com/) and MATLAB. In addition to MAYOBS1 cruise multibeam data (resolution: 30 m)18, Figs. 1, 2, 4, and 5 and Extended Data Figs. 1–3 and 6–9 include topographic and bathymetric compilation16,87,88 (https://doi.org/10.17600/14000900, https://doi.org/10.17183), the General Bathymetric Chart of the Oceans (https://www.gebco.net) and global topography from SRTM GL1 (https://catalog.data.gov/dataset/shuttle-radar-topography-mission-srtm-gl1-global-30m); Litto3D Mayotte (https://diffusion.shom.fr/presentation/litto3d-mayot2012.html). Topography and bathymetry of Fig. 5b from GeoMapApp (www.geomapapp.org) CC BY. In Fig. 5 and Extended Data Figs. 6, 8 and 9, focal mechanisms for M > 5 earthquakes are from ref. 40. In Fig. 5, M > 2.5 earthquakes are from ref. 4.
Ship-borne multibeam data were processed with the GLOBE software75. The 3D acoustic water-column data were processed using SonarScope https://wwz.ifremer.fr/flotte_en/Facilities/Shipboard-software/Analyse-et-traitement-de-l-information/SonarScope and GLOBE software: https://doi.org/10.17882/7046075. GNSS solutions were computed using the GipsyX/JPL software available at https://gipsy-oasis.jpl.nasa.gov. Deformation source modelling codes (Mogi and Nikkhoo) are available at https://github.com/IPGP/deformations-matlab, and data processing has been achieved using the WebObs open-source system available at https://ipgp.github.io/webobs/. Pressure-gauge data were processed with Python89. VLF event analysis has been performed using ObsPy90, NumPy91 and Matplotlib92. Earthquake phase picking was performed with SeisComP393, and initial locations used Hypo7183. Final locations were performed with NonLinLoc76, and results were converted back to SeisComP3 using ObsPy90.
Cesca, S. et al. Drainage of a deep magma reservoir near Mayotte inferred from seismicity and deformation. Nat. Geosci. 13, 87–93 (2020).
Lemoine, A. et al. The 2018–2019 seismo-volcanic crisis east of Mayotte, Comoros islands: seismicity and ground deformation markers of an exceptional submarine eruption. Geophys. J. Int. 223, 22–44 (2020).
Bulletin de l’ActivitéSismo-Volcanique à Mayotte Report no. 2680-1205 (REVOSIMA, 2020).
Search Earthquake Catalog (USGS, 2019); https://earthquake.usgs.gov/earthquakes/search
Zinke, J., Reijmer, J. & Thomassin, B. Systems tracts sedimentology in the lagoon of Mayotte associated with the Holocene transgression. Sediment. Geol. 160, 57–79 (2003).
Phethean, J. J. et al. Madagascar’s escape from Africa: a high‐resolution plate reconstruction for the Western Somali Basin and implications for supercontinent dispersal. Geochem. Geophys. Geosyst. 17, 5036–5055 (2016).
Pelleter, A.-A. et al. Melilite-bearing lavas in Mayotte (France): an insight into the mantle source below the Comores. Lithos 208-209, 281–297 (2014).
Class, C., Goldstein, S. L., Altherr, R. & Bachèlery, P. The process of plume–lithosphere interactions in the ocean basins—the case of Grande Comore. J. Petrol. 39, 881–903 (1998).
Claude-Ivanaj, C., Bourdon, B. & Allègre, C. J. Ra–Th–Sr isotope systematics in Grande Comore Island: a case study of plume–lithosphere interaction. Earth Planet. Sci. Lett. 164, 99–117 (1998).
Ebinger, C. J. & Sleep, N. Cenozoic magmatism throughout east Africa resulting from impact of a single plume. Nature 395, 788–791 (1998).
Reiss, M., Long, M. & Creasy, N. Lowermost mantle anisotropy beneath Africa from differential SKS‐SKKS shear‐wave splitting. J. Geophys. Res. Solid Earth 124, 8540–8564 (2019).
Class, C., Goldstein, S. L., Stute, M., Kurz, M. D. & Schlosser, P. Grand Comore Island: a well-constrained “low 3He/4He” mantle plume. Earth Planet. Sci. Lett. 233, 391–409 (2005).
Nougier, J., Cantagrel, J. & Karche, J. The Comores archipelago in the western Indian Ocean: volcanology, geochronology and geodynamic setting. J. Afr. Earth Sci. 5, 135–145 (1986).
Michon, L. in Active Volcanoes of the Southwest Indian Ocean (eds Bachelery, P. et al.) 233–244 (Springer, 2016).
Nehlig, P. et al. Report on the French Geological Map (1/30 000) Mayotte Sheet no. 1179 (BRGM, 2013).
Audru, J.-C., Guennoc, P., Thinon, I. & Abellard, O. Bathymay : la structure sous-marine de Mayotte révélée par l’imagerie multifaisceaux. Comptes Rendus Geosci. 338, 1240–1249 (2006).
Sanjuan, B. et al. Estimation du Potentiel Géothermique de Mayotte: Phase 2—Étape 2. Investigations Géologiques, Géochimiques et Géophysiques Complémentaires, Synthèse des Résultats (BRGM, 2008).
Feuillet, N. MAYOBS1 French Oceanographic Cruise, RV Marion Dufresne SISMER Database (French Oceanographic Fleet, 2019); https://doi.org/10.17600/18001217
Transit valorisé de Mayotte à Brest (SHOM, 2014); https://doi.org/10.17183/S201406900
Rubin, K. H. et al. Volcanic eruptions in the deep sea. Oceanography 25, 142–157 (2012).
Chadwick, W. W. Jr et al. Recent eruptions between 2012 and 2018 discovered at West Mata submarine volcano (NE Lau Basin, SW Pacific) and characterized by new ship, AUV, and ROV data. Front. Mar. Sci. 6, 495 (2019).
Clague, D. A. et al. Structure of Lō’ihi Seamount, Hawai’i, and lava flow morphology from high-resolution mapping. Front. Earth Sci. 7, 58 (2019).
Cole, J., Milner, D. & Spinks, K. Calderas and caldera structures: a review. Earth Sci. Rev. 69, 1–26 (2005).
Yeo, I. A. & Searle, R. High‐resolution remotely operated vehicle (ROV) mapping of a slow‐spreading ridge: mid‐Atlantic ridge 45° N. Geochem. Geophys. Geosyst. 14, 1693–1702 (2013).
Clague, D. A. et al. High-resolution AUV mapping and targeted ROV observations of three historical lava flows at Axial Seamount. Oceanography 30, 82–99 (2017).
Bachelery, P. et al. Petrological and geochemical characterization of the lava from the 2018–2019 Mayotte eruption: first results. In AGU Fall Meeting 2019 abstr. V52D–06 (AGU, 2019).
Cathalot, C. et al. Acoustic and geochemical anomalies in the water column around the newly formed volcano offshore Mayotte Island. In AGU Fall Meeting 2019 abstr. V52D–05 (AGU, 2019).
Resing, J. A. et al. Active submarine eruption of boninite in the northeastern Lau Basin. Nat. Geosci. 4, 799–806 (2011).
Baumberger, T. et al. Understanding a submarine eruption through time series hydrothermal plume sampling of dissolved and particulate constituents: West Mata, 2008–2012. Geochem. Geophys. Geosyst. 15, 4631–4650 (2014).
Baker, E. T. et al. Hydrothermal discharge during submarine eruptions: the importance of detection, response, and new technology. Oceanography 25, 128–141 (2012).
Chadwick, W. W. et al. Imaging of CO2 bubble plumes above an erupting submarine volcano, NW Rota‐1, Mariana Arc. Geochem. Geophys. Geosyst. 15, 4325–4342 (2014).
Somoza, L. et al. Evolution of submarine eruptive activity during the 2011–2012 El Hierro event as documented by hydroacoustic images and remotely operated vehicle observations. Geochem. Geophys. Geosyst. 18, 3109–3137 (2017).
Sohn, R. A. et al. Explosive volcanism on the ultraslow-spreading Gakkel ridge, Arctic Ocean. Nature 453, 1236–1238 (2008).
Tarantola, A. Linearized inversion of seismic reflection data. Geophys. Prospect. 32, 998–1015 (1984).
Anderson, E. Dynamics of formation of cone-sheets, ring-dikes, and cauldron subsidences. Proc. R. Soc. Edinb. 56, 128–157 (1937).
Nikkhoo, M., Walter, T. R., Lundgren, P. R. & Prats-Iraola, P. Compound dislocation models (CDMs) for volcano deformation analyses. Geophys. J. Int. 208, 877–894 (2016).
Dofal, A., Fontaine, F. R., Michon, L., Barruol, G. & Tkalcic, H. Crustal structure variation across the southwestern Indian Ocean from receiver functions determined at Ocean-Bottom Seismometers. In AGU Fall Meeting 2018 abstr. T43G0497 (AGU, 2018).
Merz, D., Caplan‐Auerbach, J. & Thurber, C. Seismicity and velocity structure of Lō’ihi submarine volcano and southeastern Hawai’i. J. Geophys. Res. Solid Earth 124, 11380–11393 (2019).
Wolfe, C., Okubo, P. & Shearer, P. Mantle fault zone beneath Kilauea Volcano, Hawaii. Science 300, 478–480 (2003).
Ekström, G., Nettles, M. & Dziewoński, A. The global CMT project 2004–2010: centroid-moment tensors for 13,017 earthquakes. Phys. Earth Planet. Inter. 200, 1–9 (2012).
Toda, S., Stein, R. & Sagiya, T. Evidence from the AD 2000 Izu Islands earthquake swarm that stressing rate governs seismicity. Nature 419, 58–61 (2002).
Ágústsdóttir, T. et al. Strike‐slip faulting during the 2014 Bárðarbunga‐Holuhraun dike intrusion, central Iceland. Geophys. Res. Lett. 43, 1495–1503 (2016).
Sigmundsson, F. et al. Segmented lateral dyke growth in a rifting event at Bárðarbunga volcanic system, Iceland. Nature 517, 191–195 (2015).
Jacques et al. The ongoing Mayotte crisis suggesting reactivation of a caldera structure below the Moho. In AGU Fall Meeting 2020 abstr. V040-0006 (AGU, 2020).
Gudmundsson, M. T. et al. Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow. Science 353, aaf8988 (2016).
Roche, O., Druitt, T. & Merle, O. Experimental study of caldera formation. J. Geophys. Res. Solid Earth 105, 395–416 (2000).
Kumagai, H. et al. Very-long-period seismic signals and caldera formation at Miyake Island, Japan. Science 293, 687–690 (2001).
Fazio, M., Alparone, S., Benson, P. M., Cannata, A. & Vinciguerra, S. Genesis and mechanisms controlling tornillo seismo-volcanic events in volcanic areas. Sci. Rep. 9, 1–11 (2019).
Maeda, Y. & Kumagai, H. A generalized equation for the resonance frequencies of a fluid-filled crack. Geophys. J. Int. 209, 192–201 (2017).
Sigmundsson, F. et al. Unexpected large eruptions from buoyant magma bodies within viscoelastic crust. Nat. Commun. 11, 1–11 (2020).
Famin, V., Michon, L. & Bourhane, A. The Comoros archipelago: a right-lateral transform boundary between the Somalia and Lwandle plates. Tectonophysics 789, 228539 (2020).
Armijo, R., Meyer, B., Navarro, S., King, G. & Barka, A. Asymmetric slip partitioning in the Sea of Marmara pull‐apart: A clue to propagation processes of the North Anatolian fault? Terra Nova 14, 80–86 (2002).
Dauteuil, O. & Brun, J.-P. Oblique rifting in a slow-spreading ridge. Nature 361, 145–148 (1993).
Brune, S. Evolution of stress and fault patterns in oblique rift systems: 3‐D numerical lithospheric‐scale experiments from rift to breakup. Geochem. Geophys. Geosyst. 15, 3392–3415 (2014).
Pagli, C., Yun, S.-H., Ebinger, C., Keir, D. & Wang, H. Strike-slip tectonics during rift linkage. Geology 47, 31–34 (2019).
Franke, D. et al. The offshore East African rift system: structural framework at the toe of a juvenile rift. Tectonics 34, 2086–2104 (2015).
Rufer, D., Preusser, F., Schreurs, G., Gnos, E. & Berger, A. Late Quaternary history of the Vakinankaratra volcanic field (central Madagascar): insights from luminescence dating of phreatomagmatic eruption deposits. Bull. Volcanol. 76, 817 (2014).
Peacock, D. & Anderson, M. The scaling of pull‐aparts and implications for fluid flow in areas with strike‐slip faults. J. Pet. Geol. 35, 389–399 (2012).
Pratt, M. J. et al. Shear velocity structure of the crust and upper mantle of Madagascar derived from surface wave tomography. Earth Planet. Sci. Lett. 458, 405–417 (2017).
Mazzullo, A. et al. Anisotropic tomography around La Réunion Island from Rayleigh waves. J. Geophys. Res. Solid Earth 122, 9132–9148 (2017).
Barruol, G. et al. Large-scale flow of Indian Ocean asthenosphere driven by Réunion plume. Nat. Geosci. 12, 1043–1049 (2019).
Zhong, S. & Watts, A. Lithospheric deformation induced by loading of the Hawaiian Islands and its implications for mantle rheology. J. Geophys. Res. Solid Earth 118, 6025–6048 (2013).
Watts, A. B. et al. Rapid rates of growth and collapse of Monowai submarine volcano in the Kermadec Arc. Nat. Geosci. 5, 510–515 (2012).
Chadwick, W. W. Jr et al. A recent volcanic eruption discovered on the central Mariana back-arc spreading center. Front. Earth Sci. 6, 172 (2018).
Schipper, C. I., White, J. D., Houghton, B., Shimizu, N. & Stewart, R. B. Explosive submarine eruptions driven by volatile-coupled degassing at Lōihi Seamount, Hawaii. Earth Planet. Sci. Lett. 295, 497–510 (2010).
Carey, R. et al. The largest deep-ocean silicic volcanic eruption of the past century. Sci. Adv. 4, e1701121 (2018).
Thordarson, T. & Self, S. The Laki (Skaftár Fires) and Grímsvötn eruptions in 1783–1785. Bull. Volcanol. 55, 233–263 (1993).
Neal, C. et al. The 2018 rift eruption and summit collapse of Kīlauea volcano. Science 363, 367–374 (2019).
Cogné, J.-P. & Humler, E. Temporal variation of oceanic spreading and crustal production rates during the last 180 My. Earth Planet. Sci. Lett. 227, 427–439 (2004).
Marty, B. & Tolstikhin, I. N. CO2 fluxes from mid-ocean ridges, arcs and plumes. Chem. Geol. 145, 233–248 (1998).
Debeuf, D. Étude de l’Evolution Volcano-Structurale et Magmatique de Mayotte, Archipel des Comores, Océan Indien: Approches Structurale, Pétrographique, Géochimique et Géochronologique. PhD report, Reunion Univ. (2009).
Stamps, D., Saria, E. & Kreemer, C. A geodetic strain rate model for the East African Rift System. Sci. Rep. 8, 732 (2018).
Deville, E. et al. Active fault system across the oceanic lithosphere of the Mozambique Channel: implications for the Nubia–Somalia southern plate boundary. Earth Planet. Sci. Lett. 502, 210–220 (2018).
Macgregor, D. History of the development of the East African Rift System: a series of interpreted maps through time. J. Afr. Earth Sci. 101, 232–252 (2015).
Poncelet C., Billant G, & Corre M.P. Globe (GLobal Oceanographic Bathymetry Explorer) Software (SEANOE, 2020); https://doi.org/10.17882/70460
Lomax, A., Michelini, A. & Curtis, A. in Encyclopedia of Complexity and Systems Science (ed. Meyers, R.) (Springer, 2009); https://doi.org/10.1007/978-3-642-27737-5_150-2
Poiata, N., Satriano, C., Vilotte, J.-P., Bernard, P. & Obara, K. Multiband array detection and location of seismic sources recorded by dense seismic networks. Geophys. J. Int. 205, 1548–1573 (2016).
Dupré, S. et al. Tectonic and sedimentary controls on widespread gas emissions in the Sea of Marmara: results from systematic, shipborne multibeam echo sounder water column imaging. J. Geophys. Res. Solid Earth 120, 2891–2912 (2015).
Charlou, J. L., Dmitriev, L., Bougault, H. & Needham, H. D. Hydrothermal CH4 between 12° N and 15° N over the mid-Atlantic ridge. Deep Sea Res. A 35, 121–131 (1988).
Donval, J.-P. & Guyader, V. Analysis of hydrogen and methane in seawater by “Headspace” method: determination at trace level with an automatic headspace sampler. Talanta 162, 408–414 (2017).
Bertil et al. MAYEQSwarm2018: BRGM Earthquake Catalogue for the Earthquake Swarm Located East of Mayotte (BRGM, 2018); http://ressource.brgm.fr/data/data/372c5809-3d30-440c-b44a-1c89385f176a
Hanka, W. et al. Real-time earthquake monitoring for tsunami warning in the Indian Ocean and beyond. Nat. Hazards Earth Syst. Sci. 10, 2611–2622 (2010).
Lee, W. H. K. & Lahr, J. C. HYPO71: A Computer Program for Determining Hypocenter, Magnitude, and First Motion Pattern of Local Earthquakes (USGS, 1972).
Vilaseca, G. et al. Oceanographic signatures and pressure monitoring of seafloor vertical deformation in near-coastal, shallow water areas: a case study from Santorini caldera. Mar. Geod. 39, 401–421 (2016).
Fox, C. G. In situ ground deformation measurements from the summit of Axial volcano during the 1998 volcanic episode. Geophys. Res. Lett. 26, 3437–3440 (1999).
Wessel, P. & Smith, W. H. New, improved version of Generic Mapping Tools released. Eos 79, 579–579 (1998).
MNT Bathymétrique de la Façade de Mayotte (SHOM, 2016); https://doi.org/10.17183/MNT_MAY100m_HOMONIM_WGS84
Jorry, S. PTOLEMEE French Oceanographic Cruise, RV L’Atalante SISMER database (French Oceanographic Fleet, 2014); https://doi.org/10.17600/14000900
Van Rossum, G. & Drake, F. L. Python Reference Manual (iUniverse, 2000).
Krischer, L. et al. ObsPy: a bridge for seismology into the scientific Python ecosystem. Comput. Sci. Discov. 8, 014003 (2015).
Harris, C. R. et al. Array programming with NumPy. Nature 585, 357–362 (2020).
Hunter, J. D. Matplotlib: a 2D graphics environment. Comput. Sci. Eng. 9, 90–95 (2007).
Weber, B. et al. SeisComP3—automatic and interactive real time data processing. Geophys. Res. 9, 219 (2007).
We thank A. Eyssautier and the officers and the crew of the RV Marion Dufresne (TAAF/IFREMER/LDA), GENAVIR’s coordinator, M. Boudou D’hautefeuille and the shipboard operations engineers. We thank the captain and crew of the MV Ylang (SGTM company). This research was supported by the French Ministries of Environment, Research and Overseas under a research project to N.F. (proposal INSU-CT3 TELLUS SISMAYOTTE 2019). The French National Geographic Institute (IGN) provided the Mayotte GNSS data. The la Réunion university (Laboratory of Atmosphere and Hurricanes) provided data from the DSUA station in Madagascar (contract INTERREG-5 Indian Ocean 2014–2020 "ReNovRisk-Cyclones"). We thank CNRS/INSU, IPGP, IFREMER, BRGM for additional support under internal funds. We thank our colleagues F. Tronel, A. Roulle, E. Dectot, A. Colombain, C. Doubre, Daniel Sauter, A. Dofal and A. Villié for assistance in the field, previous data acquisition, processing and model development. We thank O. Desprez de Gesincourt, L. Testut and T. Tranchant for loan and data processing of the seafloor pressure sensors. We thank the French National Marine Hydrographic and Oceanographic Service (SHOM) for providing us with previous data from the area. We thank G. Barruol for discussions. This is IPGP contribution number 4233.
The authors declare no competing interests.
Peer review information Nature Geoscience thanks Kenneth Rubin and Cynthia Ebinger for their contribution to the peer review of this work. Primary Handling Editor: Stefan Lachowycz.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended Data Fig. 1 The Mayotte Ridge.
Extended Data Fig. 2 Volcanic features offshore Mayotte.
a) 30-m resolution EM122 multibeam bathymetry (MAYOBS 1 cruise) and16,87 with locations of Fig. 2. b,c,d indicated. b), c) Interpreted MAYOBS1 shipboard bathymetry and backscatter of the upper slope east of Mayotte (location in a). Cones, lava flows and canyons as in Fig. 1b. Black dots: bathymetric depression. Dashed red lines: pre-existing caldera structure. d) Interpreted bathymetry of the lower slope east of Mayotte (localisation in a). e) zoom on d) showing monogenetic cones and lava flows.
Extended Data Fig. 3 The new volcanic edifice.
a) 2014 EM122 multibeam seafloor backscatter19. b) 2019 reflectivity (MAYOBS 1 cruise)18. c) Depth changes between the 2014 and 2019 surveys, superimposed on 2019 reflectivity. The white areas of the 2019 backscatter map exceeding the bathymetric difference map indicate the extent of new volcanic material.
Extended Data Fig. 4 CTD (conductivity temperature-depth)-Rosette measurements.
a) Nephelometry and b) temperature vertical profiles. c–g) sample analyses from 8L ®Niskin bottles. c–e) Gas concentrations(CH4, H2, CO2); f) pH, g) total alkalinity and total CO2.
Extended Data Fig. 5 Acoustic plumes over the Horseshoe volcanic structure.
a) Southward 3D view of the horseshoe morphology and two water column acoustic plumes observed on the western internal flank. b) Processed polar echogram from one EM122 multibeam ping of the data set displayed in (a) acquired on May 18th (05:41 UT) horizontal and vertical-axes correspond respectively to the cross-track distance and the water depth, in meters) – see also Acoustic plume movie 2.
Extended Data Fig. 6 Seismicity.
Top: map views, bottom: cross-sections (A-A’) projection along azimuth N115°E; (B-B’) along azimuth N45°E. a) Earthquakes recorded by onshore seismological stations before the deployment of the Ocean bottom seismometers (OBS). Colored circles are events occuring in the first six weeks of the crisis, white circles are earthquakes in the intervening 8 months. b) Earthquakes recorded by the OBS+land stations between February 25 and May 6 2019 (pink dots). Yellow diamonds: location of the Very Low Frequency (VLF) events located in this study (see supplementary 2.3). c) Focal mechanisms of the largest earthquakes from the Harvard CMT catalog40 with color scale as in a).
Extended Data Fig. 7 Global Navigation Satellite System (GNSS) data modelling and seafloor subsidence estimated from seafloor pressure variations.
a) Stations locations. Arrows with colors and names: GNSS velocity vectors (mm/yr) and station names. Coloured numbers: vertical deformation (mm/yr). Inset: yellow dots : pressure sensors on ocean bottom seismometer stations (see supplementary Fig. 2.1), red arrows: Mayotte GNSS velocity vectors (mm/yr), white arrows: far field GNSS velocity vectors. b) GNSS Time series with relative displacements recorded on the east (top), north (middle) and vertical (bottom) components of the stations between January 2018 and January 2020. c) Best fit-models with 1σ uncertainties of the GNSS data for one isotropic point source and a triple volumetric discontinuity pCDM source. d) Top panel: Pressure recorded by Seabird SBE37 gauges at the six ocean-bottom seismometer stations (Yellow dots inset Figure 7a and supplementary Fig. 2.1) de-tided and converted to vertical motion. Middle panel: vertical deformation estimated at each seafloor instrument location, using the best isotropic source model obtained from the GNSS data for the March 1st to May 1st 2019 period.
Extended Data Fig. 8 Conceptual model for the Mayotte seismo-volcanic event.
Circles and diamonds are events as in Extended Data Fig. 6. Focal mechanisms of main earthquakes are from Harvard CMT catalog40) with the same color scale as the May 10 to June 30, 2018 Volcano-Tectonic (VT) earthquakes, Yellow circle and blue patch: Location, with 3 sigma uncertainties, of the most robust isotropic source deformation model. a) Map view: The redish ellipse: Mayotte ridge, dashed circular area: old caldera structure in the morphology. Double black arrows: local extension Dashed red arrow: dyke intrusion b) Cross-section (projection along azimuth 115 degree, location on a)). Symbols as in a). Red lines: magma migration (dykes). Red ellipses and circle: magma reservoirs or mushes. Pink arrow: possible downsag along caldera structures. Redish zone: Eastern segment of the Mayotte ridge.
Extended Data Fig. 9 Regional volcano-tectonic setting of the submarine eruption offshore Mayotte.
a) Volcano-tectonic setting of the new volcanic edifice (NVE). Volcanic cones and ridges (purple) from this study and13,16,51,71. Beach balls: focal mechanisms for M>5 earthquakes40. Dotted white arrow: dyking event along the N130° E trending eastern segment of the volcanic ridge. Pink ellipse: inferred main volcano-tectonic ridges. Purple ellipses: highly damaged zones in between the en echelon ridges. Dashed grey lines: Mesozoic fracture zones6. Inset: sandbox model adapted from58 illustrating the possible arrangement of the main volcano-tectonic structures in Comoros. Thick black arrows: local extension direction.
Supplementary Sections 1–3, Figs. 2.1–2.18 and Tables 1.1, 1.2, 2.1, 2.2 and 3.1–3.3.
Supplementary Movie 1
3D flight-through over the NVE and the acoustic plume.
Supplementary Movie 2
3D flight-through over the upper insular shelf of Mayotte, the Horseshoe and the acoustic plumes.
Rights and permissions
About this article
Cite this article
Feuillet, N., Jorry, S., Crawford, W.C. et al. Birth of a large volcanic edifice offshore Mayotte via lithosphere-scale dyke intrusion. Nat. Geosci. 14, 787–795 (2021). https://doi.org/10.1038/s41561-021-00809-x
This article is cited by
Monochromatic Rayleigh Waves of a Period Around 15 s Recorded from Long-Period Earthquakes at the East of Mayotte, North Mozambique Channel, and Characteristics of Oscillations at the Source
Pure and Applied Geophysics (2022)
Detecting the effects of rapid tectonically induced subsidence on Mayotte Island since 2018 on beach and reef morphology, and implications for coastal vulnerability to marine flooding
Geo-Marine Letters (2021)