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Minto'O, Charlie Morelle Angue; Bassetti, Maria-angela; Morigi, Caterina; Ducassou, Emmanuelle; Toucanne, Samuel; Jouet, Gwenael; Mulder, Thierry. |
Foraminifera and ostracods have been quantitatively studied in core MD01-2472, from the upper continental slope (at water depth of 501 m), to evaluate their relationship with bottom water condition variability and decipher the control of the Levantine Intermediate Water (LIW) current on benthic faunas. The occurrence of reworked ostracod species (originating from the continental shelf) and, the presence of shallow water Elphidium/Ammonia benthic foraminifera are used to estimate the degree of along-slope transport at the core site. This has revealed two intervals of along-slope transport also associated with coarse-grained contourite deposits, deposited during the YD and HS2 episodes. Planktonic-benthic foraminiferal and ostracod assemblages reflect... |
Tipo: Text |
Palavras-chave: Ostracods; Foraminifera; LIW; Corsica margin. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00245/35648/34208.pdf |
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Mulder, Thierry; Cirac, Pierre; Gaudin, Mathieu; Bourillet, Jean-francois; Trainer, J.; Normand, Alain; Weber, O.; Griboulard, R.; Jouanneau, Jean-marie; Anschutz, Pierre; Jorissen, Frans. |
Submarine canyons are narrow but deep submarine valleys that extend for hundreds of meters. They represent the most impressive structures that shape the present morphology of passive continental margins. They can occur off the mouth of rivers: the Tagus, Zaire, Amazon, and Orinoco in the Atlantic; the Indus in the Indian Ocean; and the Var, Rhone, and Ebro in the Mediterranean. Some are at times disconnected from any stream mouth such as the Nazare canyon, off Portugal, despite the fact that it is close to the coast. Some were connected to a river mouth during lowstands of sea level, such as the Wilmington canyon in the northwest Atlantic, or the Blackmud canyon in the northeast Atlantic. |
Tipo: Text |
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Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00071/18201/15769.pdf |
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Toucanne, Samuel; Jouet, Gwenael; Ducassou, Emmanuelle; Bassetti, Maria-angela; Dennielou, Bernard; Minto'O, Charlie Morelle Angue; Lahmi, Marjolaine; Touyet, Nicolas; Charlier, Karine; Lericolais, Gilles; Mulder, Thierry. |
Sortable silt particle-size data and stable isotope analyses from the Corsica Trough, western Mediterranean Sea, provide a continuous palaeoceanographic record of the inflow, ventilation and vertical fluctuations of the Levantine Intermediate Water (LIW) in the northern Tyrrhenian Sea for the last 130,000 years. The results presented herein reveal that climate changes drive the Mediterranean intermediate circulation on Milankovitch to millennial time-scales. Intensified intermediate inflow and ventilation in the Corsica Trough occurred throughout the last glacial interval, with a cold / faster – warm / slower pattern existing between the Dansgaard-Oeschger climatic oscillations (including Heinrich events) and the LIW variability. By contrast, a weak... |
Tipo: Text |
Palavras-chave: Levantine Intermediate Water; Mediterranean Sea; Thermohaline circulation; Palaeoceanography. |
Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00054/16506/14023.pdf |
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Mulder, Thierry; Lecroart, P; Hanquiez, V; Marches, E; Gonthier, E; Guedes, J; Thiebot, E; Jaaidi, B; Kenyon, N; Voisset, Michel; Perez, C; Sayago, M; Fuchey, Y; Bujan, S. |
Recent multibeam bathymetry and acoustic imagery data provide a new understanding of the morphology of the western part of the Gulf of Cadiz. The gulf is under the influence of a strong current, the Mediterranean Outflow Water (MOW). This current is at the origin of the construction of the giant Contourite Depositional System. Canyons and valleys with erosive flanks are observed. Only the Portimao Canyon is presently connected to the continental shelf. Channels occur on the continental shelf but are presently disconnected from the deeper network of channels and valleys. Slumps are localized in steep slope areas. They are caused by oversteepening and overloading, sometimes probably associated with earthquake activity. Slumps transform sharply into turbidity... |
Tipo: Text |
Palavras-chave: Contour current; Interaction; Turbidity current; Geomorphology; Gulf of Cadiz. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1718.pdf |
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Migeon, Sébastien; Mulder, Thierry; Savoye, Bruno; Sage, Françoise. |
The Var turbidite system is a small sandy system located in the Ligurian Basin. It was deposited during the Pliocene-Quaternary in a flat-floored basin formed during the Messinian salinity crisis. The system was fed through time by the Var and Paillon canyons that connect directly to the Var and Paillon rivers. It is still active during the present sea-level highstand. Two main mechanisms are responsible for gravity-flow triggering in the Var turbidite system: (1) mass-wasting events affect mainly the upper part of the continental slope, in areas where volumes of fresh sediment delivered by rivers are highest, and result from the under-consolidation state of slope sediments and earthquakes, and (2) high-magnitude river floods resulting from melting of snow... |
Tipo: Text |
Palavras-chave: Geomorphology; Sediment waves; Turbidity; Mediterranean sea; Ligurian basin. |
Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/publication-2258.pdf |
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Mazieres, Alais; Gillet, Herve; Castelle, Bruno; Mulder, Thierry; Guyot, Corentin; Garlan, Thierry; Mallet, Cyril. |
In this study, the Capbreton canyon head, just off the coast, is investigated using high-resolution multibeam bathymetry datasets, sediment samples and numerical modeling. The HR bathymetry analysis reveals a morphological connection between the longshore trough and the head of the canyon. The analysis of recent sediment samples shows a clear correlation between the sediment of the canyon head and that of the nearshore. Hydrodynamic modeling (a coupled wave-flow model) shows that for high-energy waves, the rotational nature of surf-zone circulation reverses and wave-induced currents have the potential to transport large quantities of nearshore sands toward the canyon head. All these arguments support the assumption that the canyon head captures a part of... |
Tipo: Text |
Palavras-chave: Longshore drift; Submarine canyon; Capbreton; Hydrodynamic modeling; Sediment transport. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00180/29118/27524.pdf |
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Schnyder, Jara S. D.; Eberli, Gregor P.; Kirby, James T.; Shi, Fengyan; Tehranirad, Babak; Mulder, Thierry; Ducassou, Emmanuelle; Hebbeln, Dierk; Wintersteller, Paul. |
Submarine slope failures are a likely cause for tsunami generation along the East Coast of the United States. Among potential source areas for such tsunamis are submarine landslides and margin collapses of Bahamian platforms. Numerical models of past events, which have been identified using high-resolution multibeam bathymetric data, reveal possible tsunami impact on Bimini, the Florida Keys, and northern Cuba. Tsunamis caused by slope failures with terminal landslide velocity of 20 ms(-1) will either dissipate while traveling through the Straits of Florida, or generate a maximum wave of 1.5 m at the Florida coast. Modeling a worst-case scenario with a calculated terminal landslide velocity generates a wave of 4.5 m height. The modeled margin collapse in... |
Tipo: Text |
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Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00506/61772/65754.pdf |
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Mignard, Salomé; Mulder, Thierry; Martinez, Philippe; Garlan, Thierry. |
The effects of changes in slope gradient on deposition processes and architecture have been investigated in different deep-sea systems both in modern and ancient environments. However, the impact of subtle gradient changes (< 0.3∘) on sedimentary processes along deep-sea fans still needs to be clarified. The Ogooue Fan, located in the northeastern part of the Gulf of Guinea, extends over more than 550 km westwards of the Gabonese shelf and passes through the Cameroon volcanic line. Here, we present the first study of acoustic data (multibeam echosounder and 3.5 kHz, very high-resolution seismic data) and piston cores covering the deep-sea part of this West African system. This study documents the architecture and sedimentary facies distribution along... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00503/61435/65154.pdf |
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