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Escartin, Javier; Leclerc, Frederique; Olive, Jean-arthur; Mevel, Catherine; Cannat, Mathilde; Petersen, Sven; Augustin, Nico; Feuillet, Nathalie; Deplus, Christine; Bezos, Antoine; Bonnemains, Diane; Chavagnac, Valerie; Choi, Yujin; Godard, Marguerite; Haaga, Kristian A.; Hamelin, Cedric; Ildefonse, Benoit; Jamieson, John W.; John, Barbara E.; Leleu, Thomas; Macleod, Christopher J.; Massot-campos, Miguel; Nomikou, Paraskevi; Paquet, Marine; Rommevaux-jestin, Celine; Rothenbeck, Marcel; Steinfuehrer, Anja; Tominaga, Masako; Triebe, Lars; Campos, Ricard; Gracias, Nuno; Garcia, Rafael; Andreani, Muriel; Vilaseca, Geraud. |
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... |
Tipo: Text |
Palavras-chave: Submarine fault; Surface rupture; Earthquake; Fault slip; Neotectonics; Microbathymetry. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00344/45500/45051.pdf |
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Sauter, Daniel; Cannat, Mathilde; Roumejon, Stephane; Andreani, Muriel; Birot, Dominique; Bronner, Adrien; Brunelli, Daniele; Carlut, Julie; Delacour, Adelie; Guyader, Vivien; Macleod, Christopher J.; Manatschal, Gianreto; Mendel, Veronique; Menez, Benedicte; Pasini, Valerio; Ruellan, Etienne; Searle, Roger. |
The global mid-ocean ridge system, where tectonic plates diverge, is traditionally thought of as the largest single volcanic feature on the Earth. Yet, wide expanses of smooth sea floor in the easternmost part of the Southwest Indian Ridge in the Indian Ocean lacks the hummocky morphology that is typical for submarine volcanism. At other slow-spreading ridges, the sea floor can extend by faulting the existing lithosphere, along only one side of the ridge axis. However, the smooth sea floor in the easternmost Southwest Indian Ridge also lacks the corrugated texture created by such faulting. Instead, the sea floor is smooth on both sides of the ridge axis and is thought to be composed of altered mantle-derived rocks. Here we use side-scan sonar to image the... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00136/24771/22950.pdf |
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Andreani, Muriel; Escartin, Javier; Delacour, Adelie; Ildefonse, Benoit; Godard, Marguerite; Dyment, Jerome; Fallick, Anthony E.; Fouquet, Yves. |
Rainbow is a dome-shaped massif at the 36°14′N nontransform offset along the Mid-Atlantic Ridge. It hosts three ultramafic-hosted hydrothermal sites: Rainbow is active and high temperature; Clamstone and Ghost City are fossil and low temperature. The MoMARDREAM cruises (2007, 2008) presented here provided extensive rock sampling throughout the massif that constrains the geological setting of hydrothermal activity. The lithology is heterogeneous with abundant serpentinites surrounding gabbros, troctolites, chromitites, plagiogranites, and basalts. We propose that a W dipping detachment fault, now inactive, uplifted the massif and exhumed these deep-seated rocks. Present-day deformation is accommodated by SSW-NNE faults and fissures, consistent with oblique... |
Tipo: Text |
Palavras-chave: Rainbow; Hydrothermal; Serpentinization; Atlantic ridge. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00210/32151/30609.pdf |
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