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| Dupre, Stéphanie; Woodside, John; Klaucke, Ingo; Mascle, Jean; Foucher, Jean-paul. |
| The Nile deep sea fan system presents a rich variety of fluid escape structures, gas chimneys, pockmarks and carbonate crust mounds, brines pools, and several types of mud volcano. These seep-related structures were explored for the first time with the Nautile submersible during the 2003 Nautinil expedition and are characterized by high thermal gradients and highly gas-saturated sediments. More recently, high resolution side scan sonar data acquired during the 2004 Mimes expedition brings more detail to the geophysical imagery. The EdgeTech DTS-1 deep tow sonar coupled with a 2-8 kHz chirp subbottom penetrator was deployed around 100 m above the seafloor and operated at a frequency of 75 kHz. Several gas plumes were acoustically detected in the water... |
| Tipo: Text |
Palavras-chave: Free gas emission; Backscatter; Authigenic carbonate crust; Mud volcanism; Gas chimneys; Nile Deep Sea Fan. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2005/acte-6396.pdf |
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| Foucher, Jean-paul; Westbrook, Graham K.; Boetius, Antje; Ceramicola, Silvia; Dupre, Stephanie; Mascle, Jean; Mienert, Jurgen; Pfannkuche, Olaf; Pierre, Catherine; Praeg, Daniel. |
| Submarine hydrocarbon seeps are geologically driven "hotspots" of increased biological activity on the seabed. As part of the HERMES project, several sites of natural hydrocarbon seepage in the European seas were investigated in detail, including mud volcanoes and pockmarks, in study areas extending from the Nordic margin, to the Gulf of Cadiz, to the Mediterranean and Black seas. High-resolution seabed maps and the main properties of key seep sites are presented here. Individual seeps show ecosystem zonation related to the strength of the methane flux and distinct biogeochemical processes in surface sediments. A feature common to many seeps is the formation of authigenic carbonate constructions. These constructions exhibit various morphologies ranging... |
| Tipo: Text |
Palavras-chave: Mosby mud volcano; Deep sea fan; Eastern mediterranean sea; Black sea; Anaerobic oxidation; Hydrocarbon seeps; Carbonate crusts; Sidescan sonar; Hydrate ridge; Gas chimneys. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6387.pdf |
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| 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 |
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