First direct observation of coseismic slip and seafloor rupture along a submarine normal fault and implications for fault slip history
| Type | Article | ||||||||||||
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| Date | 2016-09 | ||||||||||||
| Language | English | ||||||||||||
| Author(s) | Escartin Javier1, Leclerc Frederique2, Olive Jean-Arthur3, Mevel Catherine1, Cannat Mathilde1, Petersen Sven 4, Augustin Nico4, Feuillet Nathalie1, Deplus Christine1, Bezos Antoine5, Bonnemains Diane1, Chavagnac Valerie6, Choi Yujin1, Godard Marguerite7, Haaga Kristian A.8, Hamelin Cedric8, Ildefonse Benoit7, Jamieson John W.4, John Barbara E.9, Leleu Thomas6, Macleod Christopher J.10, Massot-Campos Miguel11, Nomikou Paraskevi12, Paquet Marine1, Rommevaux-Jestin Celine1, Rothenbeck Marcel4, Steinfuehrer Anja4, Tominaga Masako13, Triebe Lars2, Campos Ricard14, Gracias Nuno, Garcia Rafael, Andreani Muriel15, Vilaseca Geraud1 |
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| Affiliation(s) | 1 : CNRS UMR7154, Inst Phys Globe Paris, Paris, France. 2 : Earth Observ Singapore, Singapore, Singapore. 3 : Lamont Doherty Earth Observ, Palisades, NY USA. 4 : GEOMAR Helmholtz Ctr Ocean Res, Kiel, Germany. 5 : Univ Nantes, Nantes, France. 6 : CNRS UMR5563, Geosci Environm Toulouse, Toulouse, France. 7 : Univ Montpellier, Geosci Montpellier, Montpellier, France. 8 : Univ Bergen, Bergen, Norway. 9 : Univ Wyoming, Laramie, WY 82071 USA. 10 : Cardiff Univ, Cardiff, S Glam, Wales. 11 : Univ Balearic Isl, Palma De Mallorca, Spain. 12 : Univ Athens, Athens, Greece. 13 : Texas A&M Univ, College Stn, TX USA. 14 : Univ Girona, Girona, Spain. 15 : Univ Lyon, Lyon, France. |
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| Source | Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2016-09 , Vol. 450 , P. 96-107 | ||||||||||||
| DOI | 10.1016/j.epsl.2016.06.024 | ||||||||||||
| WOS© Times Cited | 21 | ||||||||||||
| Keyword(s) | submarine fault, surface rupture, earthquake, fault slip, neotectonics, microbathymetry | ||||||||||||
| Abstract | 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 parameters, seismic profiles, shipboard bathymetry, coring) rather than direct ones. Using deep-sea vehicles, we identify for the first time a marker of coseismic slip on a submarine fault plane along the Roseau Fault (Lesser Antilles), and measure its vertical displacement of ∼0.9 m in situ. We also map recent fissuring and faulting of sediments on the hangingwall, along ∼3 km of rupture in close proximity to the fault's base, and document the reactivation of erosion and sedimentation within and downslope of the scarp. These deformation structures were caused by the 2004 Mw 6.3 Les Saintes earthquake, which triggered a subsequent tsunami. Their characterization informs estimates of earthquake recurrence on this fault and provides new constraints on the geometry of fault rupture, which is both shorter and displays locally larger coseismic displacements than available model predictions that lack field constraints. This methodology of detailed field observations coupled with near-bottom geophysical surveying can be readily applied to numerous submarine fault systems, and should prove useful in evaluating seismic and tsunamigenic hazard in all geodynamic contexts. | ||||||||||||
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