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| Riou, Brieuc; Chaumillon, Eric; Chagu, Catherine; Sabatier, Pierre; Schneider, Jean-luc; Walsh, John-patrick; Zawadzki, Atun; Fierro, Daniela. |
| Following recent tsunamis, most studies have focused on the onshore deposits, while the offshore backwash deposits, crucial for a better understanding of the hydrodynamic processes during such events and offering an opportunity for sedimentary archives of past tsunamis, have mostly been omitted. Here, we present a unique sedimentary record of the backwash from two historical tsunamis sampled in a sheltered bay in American Samoa, namely the 2009 South Pacific Tsunami and the 1960 Great Chilean Earthquake Tsunami. Although not always concomitant with a marked grain size change, backwash deposits are identified by terrestrial geochemical and mineralogical signatures, associated with basal soft sediment micro-deformations. These micro-deformations, including... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77079/78407.pdf |
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| Sultan, Nabil; Cattaneo, Antonio; Sibuet, Jean-claude; Schneider, Jean-luc. |
| The swath bathymetric data acquired during the "Sumatra Aftershocks" cruise from the Sunda trench in the Indian Ocean to the north of the Sumatra Island imaged several scars and deposits. In situ pore pressure measurements using the Ifremer piezometer and coring demonstrate that high excess pore pressure and sediment deformation was generated by a recent event in the scar of the slope failure zone identified by J.T. Henstock and co-authors. This excess pore pressure is localized in the upper sedimentary layers and is not related to an interplate subduction process. Numerical simulations of the hydrological system that take into account the hydro-mechanical properties of the upper sediment layer show that the excess pore pressure and sediment deformations... |
| Tipo: Text |
Palavras-chave: Tsunami; Sumatra; Slope failure; Pore pressure; Earthquake. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6740.pdf |
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| Van Vliet-lanoe, Brigitte; Schneider, Jean-luc; Gudmundsson, Agust; Guillou, Herve; Nomade, Sebastien; Chazot, Gilles; Liorzou, Celine; Guegan, Solene. |
| Central southern Iceland is one of the main outlets of the Icelandic Ice Sheet where a MIS 5e sedimentary complex, the Ranga Formation, is extensively observed below the last deglaciation terminal moraines. Sedimentary facies demonstrate that the Ranga Formation is mostly tidal, up to 215 m (transgression I) and 168 m (transgression II) in altitude. The first highstand reworks a thick tephra from the Grimsvotn volcano, known in marine cores as 5e low/Bas-IV and positioned at ca. 127 Ka BP, the Eemian thermal optimum. This formation is related to a rapid deglaciation followed by two marine transgressions marked by the development of extended mud flats, which were separated by a complex regression phase, associated with loess deposition, ca. 9 Ka in... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00638/75001/75938.pdf |
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| Kong, Eleonore; Zaragosi, Sebastien; Schneider, Jean-luc; Garlan, Thierry; Bachelery, Patrick; Sabine, Marjolaine; San Pedro, Laurine. |
| In the Ionian Sea, the subduction of the Nubia plate underneath the Eurasia plate leads to an important sediment remobilization on the Calabrian Arc and the Mediterranean Ridge. These events are often associated with earthquakes and tsunamis. In this study, we analyze gravity-driven deposits in order to establish their recurrence time on the Calabrian Arc and the western Mediterranean Ridge. Four gravity cores collected on ridges and slope basins of accretionary prisms record turbidites, megaturbidites, slumping and micro-faults over the last 330,000 years. These turbidites were dated by correlation with a hemipelagic core with a multi-proxy approach: radiometric dating, 18O, b* colour curve, sapropels and tephrochronology. The origin of the gravity-driven... |
| Tipo: Text |
Palavras-chave: Ionian Sea; Accretionary wedges; Palaeoearthquakes; Etna volcanism; Natural hazard; Turbidites. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00638/75012/75691.pdf |
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