Nathalie Feuillet

Institut de Physique du Globe de Paris

The 2018–2021 Fani Maor´e submarine eruption (offshore of Mayotte, Mozambique Channel) extruded a bulk volume of ~6.5 km3 of basanite magma onto the seafloor at a depth of 3300 m, with effusion rates ranging from 150 to 200 m3/s in the first year of the eruption, to less than 11 m3/s in the final months. Six oceanographic campaigns provided a large...

The seismic potential of the Lesser Antilles subduction zone is poorly known and highly debated. Only two damaging earthquakes have been reported in the historical period, in 1839 and 1843, but their sources and magnitude are still uncertain. Global Navigation Satellite Systems and coral data contradict each other, and no conclusion has been reache...

Decadal and multidecadal changes in the meridional overturning circulation may originate from either the subpolar North Atlantic or the Southern Hemisphere. New records of carbon and oxygen isotopes from an eastern Martinique Island (Lesser Antilles) coral reveal irregular, decadal, double-step events of low ∆ ¹⁴ C and enhanced vertical mixing, hig...

Low-lying coasts and small islands, such as in the Lesser Antilles, are particularly vulnerable to hurricane-induced marine floods. In September 2017, category 5 Hurricane Irma, with winds up to 360 km h−1, hit the northern Caribbean islands and caused the destruction of 95 % of the structures on Barbuda Island. We investigated the geomorphological...

Seismic hazard levels used as reference for the French Lesser Antilles are derived from probabilistic seismic hazard assessment studies performed in 2002. However, scientific knowledge has greatly increased over the past 20 years in this area, warranting an update of the seismic hazard models. As part of a project linking the French Ministry of Eco...

The seismic hazard posed by submarine faults and the capacity of submarine earthquakes to trigger mass wasting are poorly understood because we lack detailed characterizations of coseismic ruptures at the seafloor. Here, we present comprehensive mapping of a seafloor rupture caused by the 2004 Mw 6.3 Les Saintes earthquake on the Roseau normal faul...

The seismic hazard related to megathrust earthquakes in the Ryukyus (southern Japan) is poorly constrained as no large earthquake has been reported there. The Meiwa tsunami impacted the coasts of the Yaeyama and Miyako islands in 1771 but its origin is still debated. Global Navigation Satellite Systems measurements indicate that strain is accumulat...

Low-lying coasts and small islands, such as in the Lesser Antilles, are particularly vulnerable to hurricane-induced marine floods. In September 2017, Category 5 Hurricane Irma, with winds up to 360 km/h, hit the northern Caribbean islands and caused the destruction of 95 % of the structures on Barbuda Island. We investigated the geomorphological i...

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 wer...

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...

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 provinc...

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...

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 seq...

Three main types of factors commonly control the nature of the clasts, the arrangement of the distinctive lithologies, and the general architecture of turbidite systems: sedimentation rate and carbonate production; climates and glacio-eustatism; and morphology and tectonics. The coexistence of adjacent systems of distinctive nature is, however, sca...

Scrub Island lagoon (Anguilla, Caribbean) provides the opportunity to display both tropical cyclones, near-field and far-field tsunami deposits within the same sediment core. Here, we use X-ray tomography to highlight the sedimentary fabric and link it to processes that occurred during these events. Overall, the tsunami sedimentary fabric remains h...

In the context of increasing evidence of plate interface coupling variability in subduction zones, there is a need to extend the short time window given by instrumental data and to gather data over multiple time and spatial scales. We hence investigated the long‐term topography on Barbuda island, located in the northern part of the Lesser Antilles,...

In 2019, a new underwater volcano was discovered at 3500m 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 ongoing and the volcanic activity, along with the intense seismicity that accompanies this crisis, is monitored by the recently-created REV...

No megathrust earthquake similar to the Magnitude class 9 events in Sumatra in 2004 or in Japan in 2011 was firmly reported at the Lesser Antilles subduction zone. The largest known tsunamis followed either a strong intraplate earthquake (1867, Virgin Islands) or were transoceanic due to the 1755 Lisbon earthquake. In this region, where the converg...

The seismic potential of the Lesser Antilles megathrust remains poorly known, despite the potential hazard it poses to numerous island populations and its proximity to the Americas. As it has not produced any large earthquakes in the instrumental era, the megathrust is often assumed to be aseismic. However, historical records of great earthquakes i...

A new submarine volcano has been discovered offshore Mayotte, a part of the Comoros volcanic archipelago located between Africa and Madagascar. The edifice arose from the sea-floor following a seismo-volcanic crisis that started in May 2018. This seismo-volcanic activity highlights very deep magma reservoirs and dykes in the East Mayotte volcanic s...

A major challenge in subaqueous palaeoseismology is to understand the relationship between an earthquake/tsunami and a sedimentary event deposit recorded in drillcores. Expedition 381 of the International Ocean Discovery Program was dedicated to understanding the development of the Corinth Rift, Greece. Its drilled cores provide a potentially impor...

Unlike subaerial eruptions, the nature and dynamics of deep submarine eruptions are poorly constrained. Here we present a multiscale study of the eastern upper submarine slope of Mayotte Island, based on high-resolution bathymetry and seafloor observations carried out with autonomous underwater vehicles (AUVs) and deep-towed camera systems. Additio...

A new submarine volcano has been discovered offshore Mayotte, a part of the Comoros volcanic archipelago located between Africa and Madagascar. Regarding this seismo-volcanic activity, a 3-D passive tomography was conducted, in order to determine the structure of the volcanic plumbing system (Foix et al., 2021). Using > 3,000 earthquakes from an on...

In May 2018, a seismically quiet region of the Indian Ocean awoke. More than 130 magnitude 4+ earthquakes were recorded in the first month, including a MW 5.9 event on May 15th, 2018. This seismic activity was later identified as being related to an exceptional underwater volcanic eruption offshore Mayotte Island, which had emitted more than 6.5 km...

Deep-sea submarine eruptions are the least known type of volcanic activity, due to the difficulty of detecting, monitoring, and sampling them. Following an intense seismic crisis in May 2018, a large submarine effusive eruption offshore the island of Mayotte (Indian Ocean) has extruded at least 6.5 km3 of magma to date, making it the largest monito...

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 displac...

Since 2018, the submarine east flank of Mayotte Island (Comoros archipelago) is the site of a major eruption located at 3.5 km depth bsl on a WNW-ESE volcanic ridge. Samples brought by oceanographic cruises carried out to monitor this seismo-volcanic crisis indicate that this volcanic ridge is built by a bimodal sodic alkaline magmatic series that...

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 kno...

Understanding the processes that may be at the origin of major earthquakes in subduction zones is highly challenging, especially in the case of slowly converging areas such as the Lesser Antilles subduction zone. Our study reveals a recorded increase in seismicity rate and cumulative seismic moment over the last two decades offshore Martinique isla...

Due to challenges involved in mapping the seafloor at high‐resolution (e.g., <2 m), data are lacking to understand processes that control the evolution of submarine normal fault scarps, which cover large parts of the global seafloor. Here, we use data from autonomous deep‐sea vehicles to quantify local erosion and deposition associated with a prono...

Paleomagnetism is a powerful tool for establishing an almost continuous chronostratigraphy for an entire region. When combined with other dating methods, absolute or relative, it can be used to develop a regional reference chronostratigraphic framework. During the summer of 2016, several piston cores were collected along the Atlantic side of the Le...

A major challenge in subaqueous paleoseismology is to understand the relationship between an earthquake/tsunami and a sedimentary event deposit recorded in drillcores. Expedition 381 of the International Ocean Discovery Program was dedicated to understanding the development of the Corinth Rift, Greece. Its drilled cores provide a potentially import...

Following an intense seismic crisis in May 2018, a large submarine effusive eruption offshore the island of Mayotte (SW Indian Ocean) has extruded at least 6.4 km 3 of magma, making it the largest witnessed submarine eruption as well as the largest effusive eruption since Iceland's 1783 Laki eruption. We present a detailed petrological and geochemi...

The Comoros volcanic archipelago is related to a complex E-W zone of immature right-lateral wrenching of the lithosphere in the context of the Lwandle and Somalian plate boundaries. A major volcano-tectonic crisis began in May 2018 offshore Mayotte, the easternmost island of the archipelago, resulting in the construction of a large submarine volcan...

The Lesser Antilles are a densely populated region where local populations and industrial facilities are concentrated at the coastlines, and are therefore exposed to many rapid-onset hazards such as hurricanes and tsunamis. However, the historical catalog of these events is too short to allow risk assessment and return period estimations, and it ne...

The arc of the Lesser Antilles is associated with a significant tectonic activity due to the subduction of the Atlantic oceanic plate under the Caribbean plate. Earthquakes in this context have the potential to trigger landslides and tsunamis due to the important vertical seafloor displacement. The historical tsunamigenic earthquakes in this region...

The Lesser Antilles arc is a mixed siliciclastic and carbonate active margin made of active volcanic and flat plio-quaternary carbonate islands. It was built as a result of a complex tectonic history at the slowly converging boundary between the American plates and the Caribbean plate. The sedimentary processes as a consequence of external forcing...

This study focuses on Okinawa and Yoron islands, in order to better understand tectonics in the Ryukyu Arc related to the subduction zone. We used coral microatolls—known for their centimetric accuracy in the record of relative sea‐level (RSL) changes—to reconstruct RSL changes over the last century from living microatolls. A fossil microatoll in Y...

The relation between slip at the near surface and at depth during earthquakes is still not fully resolved at the moment. This deficiency leads to large uncertainties in the evaluation of the magnitude of past earthquakes based on surface observations, which is the only accessible evidence for such events. A better knowledge of the way slip distribu...

The Enriquillo-Plantain Garden Fault (EPGF) ruptured several times in Haiti, producing large historical earthquakes (e.g., 18 October 1751, 21 November 1751, and 3 June 1770). Their location and lateral extents are poorly known. The most devastating one, the Mw7.0, 12 January 2010 earthquake should have been the occasion to constrain the fault kine...

The active faults in Haiti were not well known and no detailed mapping of active fault traces was available before the 2010, M7.0 earthquake. The lack of detailed fault mapping hindered the interpretation of the event and the seismic hazard assessment. Here, using high-resolution LIDAR topography, aerial photographs, bathymetric charts, together wi...

After 25 years of gradual increase, volcanic unrest at la Soufrièere of Guadeloupe reached its highest seismic energy level on 27 April 2018, with the largest volcano-tectonic (VT) earthquake recorded since the 1976-1977 phreatic eruptive crisis.

Geodetic measurements reveal modern rates of tectonic deformation along subduction zones, but the kinematics of long-term deformation are typically poorly constrained. We explore the use of submarine coral reefs as a record of long-term coastal vertical motion in order to determine deformation rate and discuss its origins. The Lesser Antilles arc r...

The Mayotte Island (Indian Ocean, Comoros archipelago) is facing an exceptional, offshore, volcano-tectonic crisis. It started on May 2018, with a seismic activity eastward of Mayotte and peaked in May - June 2018 with 29 5<M<5.9+ shocks. The shocks migrated both ESE and WNW, along a N115°E trending volcanic ridge (Lemoine et al., 2019). At the ESE...

The Mayotte island (Indian Ocean, Comoros archipelago) is undergoing an exceptional offshore volcano-tectonic seismic crisis which started May 10th, 2018, peaked with a magnitude Mw5.9 on the 15th of the same month, and has produced more than two thousand M4+ events to date (Bertil 2019). To monitor this crisis, since February 2019, several French...

Volcanic eruptions are foundational events shaping the Earth's surface and providing a window into deep Earth processes and composition. Most eruptions occur on established volcanoes, exploiting longstanding magma reservoirs and pathways. Those creating new volcanoes are rare and usually too small or too remote to be well monitored, particularly in...

After 24 August and 30 October 2016 central Italy earthquakes (Mw 6.0 and 6.5, respectively), photogrammetry and geodetic survey were performed at various sites along a 6-km-long portion of the rupturing Monte Vettore fault system, providing very high-resolution georeferenced 3-D point clouds and imagery of the 24 August rupture and a data set of b...

Paleomagnetic studies have mostly focused on hemipelagic sediments, avoiding all rapidly deposited layers such as turbidites to reconstruct Earth' geomagnetic field variations. Nonetheless, a few laboratory experiments and natural sediment core studies have begun to explore the impact of such rapidly deposited layers on the paleomagnetic records in...

Sea surface reservoir ages (R) are reported from radiocarbon ( ¹⁴ C) measurements of the annual growth bands of coral Siderastrea siderea collected on the Atlantic coast off Martinique Island, in the Lesser Antilles volcanic arc. Mean values of R are similar between 1835 and 1845 during pre-anthropogenic times at 385±30 yr and between 1895 and 1905...

We provide a database of the coseismic geological surface effects following the Mw 6.5 Norcia earthquake that hit central Italy on 30 October 2016. This was one of the strongest seismic events to occur in Europe in the past thirty years, causing complex surface ruptures over an area of >400 km2. The database originated from the collaboration of sev...

We present a 1:25,000 scale map of the coseismic surface ruptures following the 30 October 2016 M w 6.5 Norcia normal-faulting earthquake, central Italy. Detailed rupture mapping is based on almost 11,000 oblique photographs taken from helicopter flights, that has been verified and integrated with field data (>7000 measurements). Thanks to the comm...

Beside classical turbidites representing fluidized gravity-reworked sediments (different from flood-induced ones), homogenites may occur, either as unique separate layers, or overlying, and associated to, a normally graded coarse interval similar to the basal terms of a turbidite. In this so-called homogenite+turbidite (HmTu), a third specific laye...

This study, focusing on the northern zone of the Lesser Antilles, aims to identify sedimentary facies (turbidite, homogeneite, hemipelagite) in sediment cores and then to correlate them in order toestablish the spatial distribution of turbidite deposits. The questions we try to answer in this preliminary study are: 1)Can several turbiditic sequence...

The Lesser Antilles subduction zone in the western Atlantic has a short historic record of earthquakes and little is known about the prehistoric record of great earthquakes and tsunami. The oblique convergence between the North America and Caribbean plates forms the Barbados Accretionary prism and may be a significant source of earthquake and tsuna...

The Lesser Antilles subduction zone in the western Atlantic has a short historic record of earthquakes and little is known about the prehistoric record of great earthquakes and tsunami. The oblique convergence between the North America and Caribbean plates forms the Barbados Accretionary prism and may be a significant source of earthquake and tsuna...

Extraordinary marine inundation scattered clasts southward on the island of Anegada, 120 km south of the Puerto Rico Trench, sometime between 1200 and 1480 calibrated years (cal yr) CE. Many of these clasts were likely derived from a fringing reef and from the sandy flat that separates the reef from the island's north shore. The scattered clasts in...

Properly assessing the extent and magnitude of fault ruptures associated with large earthquakes is critical for understanding fault behavior and associated hazard. Submarine faults can trigger tsunamis, whose characteristics are defined by the geometry of seafloor displacement, studied primarily through indirect observations (e.g., seismic event pa...

Properly assessing the extent and magnitude of fault ruptures associated with large earthquakes is critical for understanding fault behavior and associated hazard. Submarine faults can trigger tsunamis, whose characteristics are defined by the geometry of seafloor displacement, studied primarily through indirect observations (e.g., seismic event pa...

New high-resolution marine geophysical data allow to characterize a large normal fault system in the Lesser Antilles arc, and to investigate the interactions between active faulting, volcanism, sedimentary, and mass-wasting processes. Les Saintes fault system is composed of several normal faults that form a 30 km wide half-graben accommodating NE-S...

We sampled six coral microatolls that recorded the relative sea level changes over the last 230 years east of Martinique, on fringing reefs in protected bays. The microatolls are cup-shaped, which is characteristic of corals that have been experiencing submergence. X-ray analysis of coral slices and reconstructions of the highest level of survival...

We sampled six coral microatolls that recorded the relative sea level changes over the last 230 years east of Martinique, on fringing reefs in protected bays. The microatolls are cup-shaped, which is characteristic of corals that have been experiencing submergence. X-ray analysis of coral slices and reconstructions of the highest level of survival...

The prevailing consensus is that the 2010 Mw7.0 Haiti earthquake left the Enriquillo–Plantain Garden strike-slip Fault (EPGF) unruptured but broke unmapped blind north-dipping thrusts. Using high-resolution topography, aerial images, bathymetry and geology we identified previously unrecognized south-dipping NW-SE-striking active thrusts in southern...

Download for free till October 1st: http://authors.elsevier.com/a/1RWi65mVdSq3U Reef positions record the interaction between eustasy and tectonics, and have been used worldwide to characterize vertical deformations of upper-plates at different time-scales and constrain the seismic behavior of megathrusts. Along the Lesser Antilles volcanic arc, h...

IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide...

IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide...

Resulting from the interplay between tectonics and eustatism, reef terraces are powerful markers of vertical movements at a scale of 1,000 to 100,000 years. In the Lesser Antilles, they grow around every island of the archipelago and record both local and subduction-related tectonics. The recent acquisition and interpretation of very high-resolutio...

[1] At Santorini, active normal faulting controls the emission of volcanic products. Such geometry has implication on seismic activity around the plumbing system during unrest. Static Coulomb stress changes induced by the 2011–2012 inflation within a preexisting NW-SE extensional regional stress field, compatible with fault geometry, increased by m...

New high-resolution seismic data (GWADASEIS-2009 and JC45/46-2010 cruises; 72 and 60 channels respectively) combined with previous ones (AGUADOMAR-1999 and CARAVAL-2002; 6 and 24 channels respectively) allow a detailed investigation of mass-transport processes around the volcanic island of Montserrat in the Lesser Antilles. Ten submarine deposits w...

During the GWADASEIS cruise (Lesser Antilles volcanic arc, February–March 2009) a very high resolution (VHR) seismic-reflection survey was performed in order to constrain Late Quaternary to Present faulting. The profiles we obtained evidence frequent "ponding" of reworked sediments in the deepest areas, similar to the deposition of Mediterranean "h...

The oblique convergence between North American and Caribbean plates is accommodated in a bookshelf faulting manner by active, oblique-normal faults in the northern part of the Lesser Antilles arc. In the last 20 years, two M > 6 earthquakes occurred along a large, arc parallel, en echelon fault system, the 16 March 1985 in Redonda and 21 November 2...

On November 21, 2004, a magnitude 6.3 earthquake occurred offshore, 10 km south of Les Saintes archipelago in Guadeloupe (French West Indies). There were more than 30000 aftershocks recorded in the following two years, most of them at shallow depth near the islands of the archipelago. The main shock and its main aftershock of February 14, 2005 (Mw...

New high-resolution multichannel seismic data (GWADASEIS-2009 and JC45/46-2010 cruises; 72 and 60 channels, respectively) combined with previous data (AGUADOMAR-1999 and CARAVAL-2002; 6 and 24 channels, respectively) allow a detailed investigation of mass-wasting processes around the volcanic island of Montserrat in the Lesser Antilles. Seven subma...

1] New high‐resolution marine data acquired aboard R/V Le Suroît was used to map active normal faults offshore Montserrat in greater detail. The main faults of the Montserrat‐Havers fault zone have cumulative scarps up to 200 m high, and offset sedimentary layers by hundreds of meters. They are arranged in a right‐stepping, en echelon, trans‐tensio...

This contribution provides an analysis of the 1995-2009 eruptive period of Soufrière Hills volcano (Montserrat) from a unique offshore perspective. The methodology is based on five repeated swath bathymetric surveys. The difference between the 2009 and 1999 bathymetry suggests that at least 395 Mm3 of material has entered the sea. This proximal dep...

On November 21, 2004 an Mw6.3 intraplate earthquake occurred at sea in the French Caribbean. The aftershock sequence continues to this day and is the most extensive sequence in a French territory in more than a century. We recorded aftershocks from day 25 to day 66 of this sequence, using a rapidly-deployed temporary array of ocean bottom seismomet...

The Lesser Antilles arc is a region of high seismic hazard, which results from the convergence of American and Caribbean plates at 2cm/yr. Several earthquakes of magnitude >= 7 have struck the islands in the past. The largest, latest ones occurred only 4 years apart in the mid-19th century, on January 11, 1839 and February 8, 1843, destroying the t...

AGUADOMAR marine cruise data acquired 11 years ago allowed us to identified and map two main sets of active faults within the Lesser Antilles arc (Feuillet et al., 2002; 2004). The faults belonging to the first set, such as Morne-Piton in Guadeloupe, bound up to 100km-long and 50km-wide arc-perpendicular graben or half graben that disrupt the fore-...

On November 21, 2004, a magnitude 6.3 earthquake occurred offshore, 10-km south of Les Saintes archipelago in Guadeloupe (FWI). The ensuing seismic sequence lasted more than two years, with several tens of earthquakes still recorded monthly today by the Lesser Antilles monitoring network. There were more than 30,000 aftershocks, most of them at sha...