Title :

Sedimentary Records in the Lesser Antilles Fore‐Arc Basins Provide Evidence of Large Late Quaternary Megathrust Earthquakes

Author(s) :

Seibert, Chloé [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Lamont-Doherty Earth Observatory [LDEO]
Feuillet, Nathalie [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Ratzov, G. [Auteur]
Géoazur [GEOAZUR 7329]
Beck, Christian [Auteur]
Institut des Sciences de la Terre [ISTerre]
Morena, P. [Auteur]
Géoazur [GEOAZUR 7329]
Geo-Ocean [GEO-OCEAN]
Université de Brest [UBO]
Johannes, L. [Auteur]
Muséum national d'Histoire naturelle [MNHN]
Ducassou, E. [Auteur]
Environnements et Paléoenvironnements OCéaniques [EPOC]
Cattaneo, A. [Auteur]
Geo-Ocean [GEO-OCEAN]
Goldfinger, C. [Auteur]
College of Earth, Ocean and Atmospheric Sciences [Corvallis] [CEOAS]
Moreno, Eva [Auteur]
Variabilité de l'Océan et de la Glace de mer [LOCEAN-VOG]
Bieber, A. [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Institut des Sciences de la MER de Rimouski [ISMER]
Bénâtre, G. [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Caron, Benoît [Auteur]
Institut des Sciences de la Terre de Paris [iSTeP]
Caron, M. [Auteur]
Institut des Sciences de la MER de Rimouski [ISMER]
Casse, M. [Auteur]
Institut des Sciences de la MER de Rimouski [ISMER]
Cavailhes, T. [Auteur]
Environnements et Paléoenvironnements OCéaniques [EPOC]
del Manzo, G. [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Deschamps, C. [Auteur]
Institut des Sciences de la MER de Rimouski [ISMER]
Desiage, P. [Auteur]
Institut des Sciences de la MER de Rimouski [ISMER]
Duboc, Q. [Auteur]
Institut des Sciences de la MER de Rimouski [ISMER]
Fauquembergue, K. [Auteur]
Environnements et Paléoenvironnements OCéaniques [EPOC]
Ferrant, A. [Auteur]
Unité Recherches et Développements Technologiques [RDT]
Guyard, H. [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Jacques, E. [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Laurencin, M. [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Leclerc, Frédérique [Auteur]
Géoazur [GEOAZUR 7329]
Patton, J. [Auteur]
College of Earth, Ocean and Atmospheric Sciences [Corvallis] [CEOAS]
Saurel, J. [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
St-Onge, G. [Auteur]
Institut des Sciences de la MER de Rimouski [ISMER]
Woerther, P. [Auteur]
Unité Recherches et Développements Technologiques [RDT]

Journal title :

Geochemistry, Geophysics, Geosystems

Publisher :

AGU and the Geochemical Society

Publication date :

2024-01-31

HAL domain(s) :

Planète et Univers [physics]/Sciences de la Terre

English abstract : [en]

Abstract 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 ...
Show more >Abstract 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 reached on the coupling ratio of the plate interface. Given the threat posed by the possible occurrence of a large megathrust earthquake, it is crucial to gain information on prehistorical events. We present the results of a submarine paleoseismological study that covers an exceptional ∼120 Kyr‐long period. We studied the sediments sampled in six up to 26 m‐long piston cores collected in deep fore‐arc basins located over the epicentral region of the 1843 earthquake. Using a multiproxy approach combining geophysical, geochemical, and sedimentological analysis, biostratigraphy and radiocarbon dating, we identified, characterized, and dated numerous event deposits that we then correlated with the sampled basins over an up to 160 km‐long area. We show that at least 33 earthquakes likely triggered these sediment remobilizations in the last 120 Kyr. Four of these events promoted exceptional deposits of turbidites + homogenites. From peak ground acceleration calculated for potential earthquakes occurring on various faults, and the absence of deposits linked to the historical earthquakes, we propose that the sources are likely megathrust earthquakes. Over the last 60 Kyr, we inferred at least three 15–25 Kyr‐long seismic cycles in which the recurrence times of earthquakes shortens from ∼5 to ∼2 Kyr.Show less >

Language :

Anglais

Popular science :

Non

Collections :

• Laboratoire d'Océanologie et de Géosciences (LOG) - UMR 8187

Source :

Harvested from HAL