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Gasperini, Luca; Stucchi, Massimiliano; Cedro, Vincenzo; Meghraoui, Mustapha; Ucarkus, Gulsen; Polonia, Alina. |
A new analysis of high-resolution multibeam and seismic reflection data, collected during several oceanographic expeditions starting from 1999, allowed us to compile an updated morphotectonic map of the North Anatolian Fault below the Sea of Marmara. We reconstructed kinematics and geometries of individual fault segments, active at the time scale of 10 ka, an interval which includes several earthquake cycles, taking as stratigraphic marker the base of the latest marine transgression. Given the high deformation rates relative to sediment supply, most active tectonic structures have a morphological expression at the seafloor, even in presence of composite fault geometries and/or overprinting due to mass-wasting or turbidite deposits. In the frame of the... |
Tipo: Text |
Palavras-chave: North Anatolian fault; Sea of Marmara; Earthquakes; Active fault segments; Marine geophysics; Seismic hazard. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79575/82244.pdf |
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Geli, Louis; Lee, T; Cochran, J; Francheteau, J; Abbott, D; Labails, Cinthia; Appriou, D. |
We analyze available heat flow data from the flanks of the Southeast Indian Ridge adjacent to or within the Australian-Antarctic Discordance (AAD), an area with patchy sediment cover and highly fractured seafloor as dissected by ridge- and fracture-parallel faults. The data set includes 23 new data points collected along a 14-Ma old isochron and 19 existing measurements from the 20- to 24-Ma old crust. Most sites of measurements exhibit low heat flux (from 2 to 50 mW m(-2)) with near-linear temperature-depth profiles except at a few sites, where recent bottom water temperature change may have caused nonlinearity toward the sediment surface. Because the igneous basement is expected to outcrop a short distance away from any measurement site, we hypothesize... |
Tipo: Text |
Palavras-chave: Mid ocean ridges; Heat flow; Marine geophysics. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3878.pdf |
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Kaub, C; Geoffroy, Laurent; Bollinger, L; Perrot, Julie; Le Roy, Pascal; Authemayou, C. |
The ∼M6 1799 Bouin earthquake is considered as one of the largest earthquakes to have struck Western France. However, the seismogenic source potentially responsible for this event remain marginally documented. We present results from a focused offshore-onshore multidisciplinary survey in its meizoseismal area in order to identify the fault segments that potentially ruptured during this earthquake. Based on macroseismic data and the geology, we focused our study on the so-called Machecoul Fault as a potential source of the 1799 Bouin event. Our survey includes extensive high-resolution seismic reflection, high resolution bathymetry and a one-year seismological survey. These data were combined with existing topography, onshore gravity data and drill data to... |
Tipo: Text |
Palavras-chave: Intra-plate processes; Seismicity and tectonics; Marine geophysics; Geomorphology; Europe. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79394/81927.pdf |
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Vanneste, Maarten; Sultan, Nabil; Garziglia, Sebastien; Forsberg, Carl Fredrik; L'Heureux, Jean-sebastien. |
In this paper, we present the current practice of investigations of seafloor instabilities and deformation processes, based on extensive research conducted over the last years, which sets the scene for future research activities in this field. The mapping of the continental margins and coastal areas with ever increasing resolution systematically reveals evidence of instabilities and deformation processes, both active and palaeo-features. In order to properly assess the hazards and risks related to these features, an integrated and multi-disciplinary approach is essential, but challenging. Such an approach consists of combining field data (geophysics, geology, sedimentology, geochemistry and geotechnical data) with numerical simulations constrained by... |
Tipo: Text |
Palavras-chave: Marine geotechnics; Slope stability; Sediment failures; Fluid flow; Shear strength; Marine geophysics; Monitoring; Excess pore pressure; Site investigations. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28378/26692.pdf |
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