Consulta: subjectFacets:"Seafloor morphology"
Registros recuperados: 7
Data/hora: 09/06/2024 10:46:47

Abyssal hill characterization at the ultraslow spreading Southwest Indian Ridge
Provedor de dados: 5
Autores: Sloan, Heather; Sauter, Daniel; Goff, John A.; Cannat, Mathilde.
The morphology of the flanks of the Southwest Indian Ridge holds a record of seafloor formation and abyssal hill generation at an ultraslow spreading rate. Statistical analysis of compiled bathymetry and gravity data from the flanks of the Southwest Indian Ridge from 54 degrees E to 67 degrees E provides estimates of abyssal hill morphologic character and inferred crustal thickness. The extent of the compiled data encompasses a spreading rate change from slow to ultraslow at similar to 24 Ma, a significant inferred variation in sub-axis mantle temperature, and a patchwork of volcanic and non-volcanic seafloor, making the Southwest Indian Ridge an ideal and unique location to characterize abyssal hills generated by ultraslow spreading and to examine the...
Tipo: Text
Palavras-chave: Southwest Indian Ridge; Abyssal hills; Seafloor morphology.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00266/37682/36757.pdf

Morphology, distribution and origin of recent submarine landslides of the Ligurian Margin (North-western Mediterranean): some insights into geohazard assessment
Provedor de dados: 5
Autores: 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

Distribution, morphology and triggers of submarine mass wasting in the Sea of Marmara
Provedor de dados: 5
Autores: Zitter, T. A. C.; Grall, Celine; Henry, Pierre; Ozeren, M.s.; Cagatay, M. Namik; Sengor, A.m.c.; Gasperini, Luca; Mercier De Lepinay, Marion; Geli, L.
An overview is given of mass wasting features along the slopes of the Sea of Marmara, Turkey, based on new data and previously published information. The Sea of Marmara is characterized by active tectonics along the North Anatolian Fault and by eustatic sea level changes controlling the connections both to the Mediterranean and Black Sea (i.e. lacustrine and marine conditions during sea-level low and high stands, respectively). High resolution bathymetric data, subsurface echo-sounder and seismic reflection profiling, seafloor visual observations, as well as stratigraphic analysis of sediment cores have been used to identify, map and date submarine slope failures and mass wasting deposits. Gravity mass movements are widespread on the steep slopes of the...
Tipo: Text
Palavras-chave: Sea of Marmara; Mass wasting; Seafloor morphology; Sea-level; Normal faulting.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00112/22351/20029.pdf

The Congolobe project, a multidisciplinary study of Congo deep-sea fan lobe complex: Overview of methods, strategies, observations and sampling
Provedor de dados: 5
Autores: Rabouille, C.; Olu, Karine; Baudin, F.; Khripounoff, Alexis; Dennielou, Bernard; Arnaud-haond, Sophie; Babonneau, Nathalie; Bayle, Christophe; Beckler, J.; Bessette, Sandrine; Bombled, B.; Bourgeois, S.; Brandily, Christophe; Caprais, Jean-claude; Cathalot, Cecile; Charlier, K.; Corvaisier, R.; Croguennec, Chantal; Cruaud, Perrine; Decker, Carole; Droz, L.; Gayet, Nicolas; Godfroy, Anne; Hourdez, S.; Le Bruchec, J.; Saout, Johan; Le Saout, Marie-helene; Lesongeur, Francoise; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Mouchel, Olivier; Noel, Philippe; Pastor, Lucie; Picot, M.; Pignet, Patricia; Pozzato, L.; Pruski, A. M.; Rabiller, Manuella; Raimonet, M.; Ragueneau, O.; Reyss, J. L.; Rodier, Philippe; Ruesch, Blandine; Ruffine, Livio; Savignac, F.; Senyarich, C.; Schnyder, J.; Sen, Arunima; Stetten, E.; Sun, Ming Yi; Taillefert, M.; Teixeira, S.; Tisnerat-laborde, N.; Toffin, Laurent; Tourolle, Julie; Toussaint, F.; Vetion, G.; Jouanneau, J. M.; Bez, M.
The presently active region of the Congo deep-sea fan (around 330 000 km2), called the terminal lobes or lobe complex, covers an area of 2500 km2 at 4700–5100 m water depth and 750–800 km offshore. It is a unique sedimentary area in the world ocean fed by a submarine canyon and a channel-levee system which presently deliver large amounts of organic carbon originating from the Congo River by turbidity currents. This particularity is due to the deep incision of the shelf by the Congo canyon, up to 30 km into the estuary, which funnels the Congo River sediments into the deep-sea. The connection between the river and the canyon is unique for major world rivers.  In 2011, two cruises (WACS leg 2 and Congolobe) were conducted to simultaneously investigate the...
Tipo: Text
Palavras-chave: Chemosynthetic habitats; Congo deep-sea fan; Fine sediment; Sedimentation rate; Seafloor morphology; Turbidite; Vesicomyidae.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00335/44580/44298.pdf

High-resolution mapping of large gas emitting mud volcanoes on the Egyptian continental margin (Nile Deep Sea Fan) by AUV surveys
Provedor de dados: 5
Autores: Dupre, Stephanie; Buffet, G.; Mascle, J.; Foucher, Jean-paul; Gauger, S.; Boetius, A.; Marfia, Christian.
Two highly active mud volcanoes located in 990-1,265 m water depths were mapped on the northern Egyptian continental slope during the BIONIL expedition of R/V Meteor in October 2006. High-resolution swath bathymetry and backscatter imagery were acquired with an autonomous underwater vehicle (AUV)-mounted multibeam echosounder, operating at a frequency of 200 kHz. Data allowed for the construction of similar to 1 m pixel bathymetry and backscatter maps. The newly produced maps provide details of the seabed morphology and texture, and insights into the formation of the two mud volcanoes. They also contain key indicators on the distribution of seepage and its tectonic control. The acquisition of high-resolution seafloor bathymetry and acoustic imagery maps...
Tipo: Text
Palavras-chave: Eastern Mediterranean; Seafloor morphology; Backscatter; Bathymetry; AUV; Nile Deep Sea Fan; Mud volcanoes.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6395.pdf

Seafloor geological studies above active gas chimneys off Egypt (Central nile deep sea fan)
Provedor de dados: 5
Autores: Dupre, Stephanie; Woodside, J; Foucher, Jean-paul; De Lange, G; Mascle, J; Boetius, A; Mastalerz, V; Stadnitskaia, A; Ondreas, Helene; Huguen, C; Harmegnies, Francois; Gontharet, Swanne; Loncke, L; Deville, E; Niemann, H; Omoregie, E; Olu, Karine; Fiala Medioni, A; Dahlmann, A; Caprais, Jean-claude; Prinzhofer, A; Sibuet, Myriam; Pierre, C; Damste, J.
Four mud volcanoes of several kilometres diameter named Amon, Osiris, Isis, and North Alex and located above gas chimneys on the Central Nile Deep Sea Fan, were investigated for the first time with the submersible Nautile. One of the objectives was to characterize the seafloor morphology and the seepage activity across the mud volcanoes. The seepage activity was dominated by emissions of methane and heavier hydrocarbons associated with a major thermal contribution. The most active parts of the mud volcanoes were highly gas-saturated (methane concentrations in the water and in the sediments, respectively, of several hundreds of nmol/L and several mmol/L of wet sediment) and associated with significantly high thermal gradients (at 10 m below the seafloor,...
Tipo: Text
Palavras-chave: Seafloor morphology; Methane; Authigenic carbonate precipitation; Gas chimneys; Mud breccia; Mud volcanoes; Fluid seepage; Nile fan.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-4455.pdf

Impact of lower plate structure on upper plate deformation at the NW Sumatran convergent margin from seafloor morphology
Provedor de dados: 5
Autores: Graindorge, D; Klingelhoefer, Frauke; Sibuet, Jean-claude; Mcneill, L; Henstock, T; Dean, S; Gutscher, M; Dessa, J; Permana, H; Singh, S; Leau, H; White, N; Carton, H; Malod, Jacques-andre; Rangin, C; Aryawan, K; Chaubey, A; Chauhan, A; Galih, D; Greenroyd, C; Laesanpura, A; Prihantono, J; Royle, G; Shankar, U.
We present results from multibeam bathymetric data acquired during 2005 and 2006, in the region of maximum slip of the 26 Dec. 2004 earthquake (Mw 9.2). These data provide high-resolution images of seafloor morphology of the entire NW Sumatra forearc from the Sunda trench to the submarine volcanic arc just north of Sumatra. A slope gradient analysis of the combined dataset accurately highlights those portions of the seafloor shaped by active tectonic, depositional and/or erosional processes. The greatest slope gradients are located in the frontal 30 km of the forearc, at the toe of the accretionary wedge. This suggests that long-term deformation rates are highest here and that probably only minor amounts of slip are accommodated by other thrust faults...
Tipo: Text
Palavras-chave: Sumatra; Tectonic; Seafloor morphology; Accretionary wedge; Subduction.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-5166.pdf