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| Registros recuperados: 11 | |
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| Courboulex, Francoise; Mercerat, E. Diego; Deschamps, Anne; Migeon, Sebastien; Baques, Marion; Larroque, Christophe; Rivet, Diane; Hello, Yann. |
| A broadband seismological station (PRIMA) installed offshore Nice airport (southeastern France) reveals a strong amplification effect of seismic waves. PRIMA station was in operation for 2 years (9/2016 to 10/2018) on the outer shelf at a water depth of 18 m. Situated at the mouth of the Var River, this zone is unstable and prone to landslides. A catastrophic landslide and tsunami already occurred in 1979, causing 10 casualties. Given the level of seismicity of the area, it is important to infer the impact of an earthquake on this zone. We analyze the recordings of earthquakes and seismic noise at the PRIMA station by comparing them to nearby inland stations. We find that the seismic waves are strongly amplified at PRIMA at some specific frequencies (with... |
| Tipo: Text |
Palavras-chave: Earthquakes; Site effects; Landslides; Offshore seismometer; Seismic hazard. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77081/78405.pdf |
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| Migeon, Sebastien; Cattaneo, Antonio; Hassoun, Virginie; Larroque, Christophe; Corradi, Nicola; Fanucci, Francesco; Dano, Alexandre; De Lepinay, Bernard Mercier; Sage, Francoise; Gorini, Christian. |
| Based on new multibeam bathymetric data, seismic-reflection profiles and side-scan sonar images, a great number of submarine failures of various types and sizes was identified along the northern margin of the Ligurian Basin and characterized with 3 distinct end-members concerning their location on the margin, sedimentary processes and possible triggering mechanisms. They include superficial landslides mainly located in the vicinity of the main mountain-supplied rivers and on the inner walls of canyons (typically smaller that 10(8) m(3) in volume: Type 1), deep scars 100-500 m high along the base of the continental slope (Type 2), and large-scale scars and Mass Transport Deposits (MTDs) affecting the upper part of the slope (Type 3 failures). The MTDs are... |
| Tipo: Text |
Palavras-chave: Ligurian Sea; Submarine landslides; Seafloor morphology; Seismic-reflection profiles; Side-scan sonar. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15387/14028.pdf |
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| Bourillet, Jean-francois; Damy, Gilbert; Dussud, Loic; Sultan, Nabil; Woerther, Patrice; Migeon, Sebastien. |
| Various observations pointed out that cores performed with gravity piston corer show signifi cant distortions mainly located at the top of the core. A series of 15 cores were performed at the same location on a submarine sand wave (Var canyon, France). Six different settings of the corer – three freefall heights and three slacks of the piston cable – were tested, including duplicates. Two accelerometers recorded simultaneously the movements of the core tube and the movements of the triggering arm. Then the z displacements were obtained by a double integration versus time of the measured acceleration. The analyses of results allowed the authors to estimate the amplitude and the duration of the elastic recoil of the aramid cable, andto distinguish four steps... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00071/18198/15766.pdf |
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| Dano, Alexandre; Praeg, Daniel; Migeon, Sebastien; Augustin, Jean-marie; Ceramicola, Silvia; Ketzer, Joao Marcelo; Augustin, Adolfo Herbert; Ducassou, Emmanuelle; Mascle, Jean. |
| The central Nile Deep-Sea Fan contains a broad area of seabed destabilisation in association with fluid seepage: slope-parallel sediment undulations are associated with multibeam high-backscatter patches (HBPs) related to authigenic carbonates. During the 2011 APINIL campaign, a deep-towed sidescan and profiling system (SAR) was used to acquire high-resolution data along three transects across water depths of 1,700-2,650 m. Three seabed domains are distinguished, all developed within stratified sediments overlying mass-transport deposits (MTDs). Upslope of the undulations (<1,950 m), sidescan HBPs record focused fluid seepage via seabed cracks. In the western area of undulations, sidescan HBPs are distinct from intermediate-backscatter patches (IBPs)... |
| Tipo: Text |
Palavras-chave: Fluid seepage; Sediment deformation; Backscatter; Gas flares. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00226/33752/37059.pdf |
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| Praeg, Daniel; Ketzer, Joao Marcelo; Augustin, Adolfo Herbert; Migeon, Sebastien; Ceramicola, Silvia; Dano, Alexandre; Ducassou, Emmanuelle; Dupre, Stephanie; Mascle, Jean; Rodrigues, Luiz Frederico. |
| On the central Nile deep-sea fan, stratified sediments overlying mass-transport deposits (MTDs) are deformed into slope-parallel seabed undulations associated with fluid seepage. The western part of this system, in water depths of 1,950–2,250 m, is examined using multi-frequency data from hull-mounted and deep-towed swath/profiling systems. Sub-bottom profiles show sub-vertical fluid pipes that terminate both at and below seabed, and gas signatures along fault planes bounding the undulations. Fluid seepage is recorded by high- to intermediate-backscatter patches (HBPs, IBPs) that differ in appearance on multibeam imagery (30 kHz, ≤3 m penetration) and sidescan swaths (170/190 kHz, <0.1 m penetration). Comparison of the two suggests a distinction of (a)... |
| Tipo: Text |
Palavras-chave: Slope undulations; Fluid seeps; Backscatter; Carbonates; Pipes; Faults. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00158/26956/25251.pdf |
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| Cattaneo, Antonio; Badhani, Shray; Caradonna, Cristina; Bellucci, Massimo; Leroux, Estelle; Babonneau, Nathalie; Garziglia, Sebastien; Poort, Jeffrey; Akhmanov, Grigorii G.; Bayon, Germain; Dennielou, Bernard; Jouet, Gwenael; Migeon, Sebastien; Rabineau, Marina; Droz, Laurence; Clare, Michael. |
| Megabeds are thick sedimentary layers extending over thousands square kilometres in deep sea basins and are thought to result from large slope failures triggered by major external events. Such deposits have been found in at least three areas of the Mediterranean Sea. Although their discovery dates back to the early 1980s, many questions remain, concerning their initiation, source area, extent, and the nature of their emplacement. One of the largest previously documented megabeds was emplaced during the Last Glacial Maximum across the Balearic Abyssal Plain with a thickness of 8-10 m in water depths of up to 2800 m. New 3.5 kHz sub-bottom profiles and sediment cores provide greater constraint on the lateral variability of the megabed and allow to map it... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72597/71595.pdf |
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| Collot, Jean-yves; Ratzov, Gueorgui; Silva, P.; Proust, J.‐n.; Migeon, Sebastien; Hernandez, M.‐j.; Michaud, F.; Pazmino, A.; Barba Castillo, D.; Alvarado, A.; Khumara, S.. |
| Deciphering the migration pattern of the Esmeraldas submarine Canyon (EC) and its history of cut‐and‐fill allows constraining the Pliocene‐Pleistocene tectonic evolution of the Ecuador‐Colombia convergent margin. Swath bathymetry, multichannel seismic reflection and chronological data show that the EC is a 143‐km–long, shelf‐incising, river‐connected canyon that started incising slope apron deposits in the Manglares fore‐arc basin ~ 5.3 Ma ago. The EC inception appears contemporaneous with the subduction of the Carnegie Ridge that is believed to have initiated 5‐6 Myr ago and is considered an indirect cause of the EC formation. During its two‐stage left‐lateral migration, the EC upper‐half scoured deep incisions providing evidences for uplift episodes in... |
| Tipo: Text |
Palavras-chave: Convergent margin tectonics; Submarine canyon; Fore-arc basin; Natural hazards; Paleoseismology. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62060/66236.pdf |
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| Poort, Jeffrey; Lucazeau, Francis; Le Gal, Virginie; Dal Cin, Michaela; Leroux, Estelle; Bouzid, Abderrezak; Rabineau, Marina; Palomino, Désirée; Battani, Anne; Akhmanov G., Grigory; Ferrante G., Matilde; Gafurova R., Dina; Si Bachir, Roza; Koptev, Alexander; Tremblin, Maxime; Bellucci, Massimo; Pellen, Romain; Camerlenghi, Angelonghi; Migeon, Sebastien; Alonso, Belen; Ercilla, Gemma; Yelles-chaouche A., Karim; Khlystov M., Oleg. |
| The Western Mediterranean basin has been formed by Miocene back-arc extension and is underlain by a thin and young lithosphere. This young lithosphere is warm, as testified by an overall elevated offshore heat flow. Heat flow within the Western Mediterranean is, however, highly variable and existing data are unevenly distributed and poorly studied in the central part of the Liguro-Provençal and Algero-Balearic basins. This central part is floored by a young oceanic crust, bordered by different continental margins, cut by transform faults, and filled by up to 8 km of sediments. We present a total of 148 new heat flow data collected during the MedSalt and WestMedFlux cruises in 2015 and 2016 and aligned along seven regional profiles that show an important... |
| Tipo: Text |
Palavras-chave: Heat flow; Western Mediterranean Sea; Liguro-Provencal basin; Algero-Balearic basin; Continental margins; Oceanic crust. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00588/70052/67992.pdf |
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| Collot, Julien; Migeon, Sebastien; Spence, G.; Legonidec, Y.; Marcaillou, B.; Schneider, J.-l.; Michaud, F.; Alvarado, A.; Lebrun, J.-f.; Sosson, M.; Pazmino, A.. |
| cuador and southwest (SW) Colombia suffered widespread damage during the twentieth century as a result of some of the greatest subduction earthquakes and associated tsunamis ever recorded. In 1906, the Ecuador‐SW Columbia margin, located at the transition between the continent and deep ocean, ruptured over a 500‐kilometer length as a single great (Mw = 8.8) subduction earthquake (Figure 1a) [Kelleher, 1972]. The 1906 rupture zone was partially reactivated in 1942, 1958, and 1979 by earthquakes of Mw 7.7 to 8.2 (Figure 1b), with 100‐200 kilometerlong rupture zones [Beck and Ruff, 1984]. Such considerable variation in earthquake rupture length and magnitude in this area's seismic cycles during the last century has raised questions about the nature and... |
| Tipo: Text |
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| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00451/56257/57826.pdf |
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| Registros recuperados: 11 | |
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