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| Registros recuperados: 29 | |
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| Omoregie, Enoma O.; Niemann, Helge; Mastalerz, Vincent; De Lange, Gert J.; Stadnitskaia, Alina; Mascle, Jean; Foucher, Jean-paul; Boetius, Antje. |
| The Eastern Mediterranean hosts a variety of active cold seep systems, such as gas chimneys, mud volcanoes and pockmarks, in water depths of 500 to 3200 m. As part of the NAUTINIL expedition in 2003, the sediments of cold seeps on the Nile Deep Sea Fan (NDSF) were sampled for the first time for biogeochemical and microbiological analyses. Here we compare rates of the anaerobic oxidation of methane (AOM) and sulfate reduction (SR) as well as the microbial community structure of a variety of cold seep systems including mud volcanoes, pockmarks and brine seeps. Our results revealed strong differences in microbial activity among the different seep systems of the Eastern, Central and Western provinces of the NDSF, as well as the Olimpi field (Central... |
| Tipo: Text |
Palavras-chave: Methane oxidation; Sulfate reduction; Archaea; Cold seeps; Mud volcano; Pockmarks; Nile Deep Sea Fan. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11087/7910.pdf |
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| Mascle, J.; Huguen, C.; Benkhelil, J.; Chamot-rooke, N.; Chaumillon, E.; Foucher, Jean-paul; Griboulard, R.; Kopf, A.; Lamarche, G.; Volkonskaia, A.; Woodside, J.; Zitter, T.. |
| Aspects of the initial stages of a collision between European and African plates may have been documented in a geophysical survey of the central Mediterranean Ridge (MR) conducted last year. The idea of an incipient collision was first suggested by Finetti [1976],and details of the seafloor and tectonic deformation along the MR, revealed for the first time in the survey, seem to point in that direction. A unique opportunity may therefore exist for studying the beginnings of such a collision—between the passive margin of a major plate (Africa) acting as a continental indenter against the active margin of another plate (Europe). More wide angle data, deep penetrating multichannel seismic data, and drilling data are crucial to better assess the nature and the... |
| Tipo: Text |
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| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00451/56252/57823.pdf |
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| Sauter, Eberhard; Muyakshin, Sergey; Charlou, Jean-luc; Schluter, Michael; Boetius, Antje; Jerosch, Kerstin; Damm, Ellen; Foucher, Jean-paul; Klages, Michael. |
| The assessment of climate change factors includes a constraint of methane sources and sinks. Although marine geological Sources are recognized as significant, unfortunately, most submarine sources remain poorly quantified. Beside cold vents and coastal anoxic sediments, the large number of submarine mud volcanoes (SMV) may contribute significantly to the oceanic methane pool. Recent research suggests that methane primarily released diff-usively from deep-sea SMVs is immediately oxidized and, thus, has little climatic impact. New hydro-acoustic, Visual, and geochemical observations performed at the deep-sea mud volcano Hakon Mosby reveal the discharge of gas hydrate-coated methane bubbles and gas hydrate flakes forming huge methane plumes extending from... |
| Tipo: Text |
Palavras-chave: Hydro acoustics; Gas hydrates; Gas bubbles; Submarine mud volcanoes; Methane budget; Plume; Methane sources. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1345.pdf |
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| Niemann, H; Losekann, T; De Beer, D; Elvert, M; Nadalig, T; Knittel, K; Amann, R; Sauter, E; Schluter, M; Klages, M; Foucher, Jean-paul; Boetius, A. |
| Mud volcanism is an important natural source of the greenhouse gas methane to the hydrosphere and atmosphere(1,2). Recent investigations show that the number of active submarine mud volcanoes might be much higher than anticipated ( for example, see refs 3 - 5), and that gas emitted from deep-sea seeps might reach the upper mixed ocean(6-8). Unfortunately, global methane emission from active submarine mud volcanoes cannot be quantified because their number and gas release are unknown(9). It is also unclear how efficiently methane-oxidizing microorganisms remove methane. Here we investigate the methane-emitting Haakon Mosby Mud Volcano (HMMV, Barents Sea, 72 degrees N, 14 degrees 44' E; 1,250 m water depth) to provide quantitative estimates of the in situ... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-4514.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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| Huguen, Caroline; Foucher, Jean-paul; Mascle, J.; Ondreas, Helene; Thouement, M.; Gontharet, S.; Stadnitskaia, A.; Pierre, C.; Bayon, Germain; Loncke, L.; Boetius, A.; Bouloubassi, I.; De Lange, G.; Caprais, Jean-claude; Fouquet, Yves; Woodside, J.; Dupre, Stephanie. |
| This paper reports the first "in situ" seafloor observations of fluid escape structures in a fault-controlled caldera-type depression of about 8 km diameter, named the Menes caldera, in the Eastern Mediterranean sea off Egypt (western province of the Nile Deep Sea Fan). A detailed analysis of seven Nautile dives, performed during the Nautinil cruise in 2003, focused on determining the nature, origin, importance, mechanisms and environmental impacts of the fluid escape processes from the geological observations. Seafloor maps, constructed from direct visual observations and video records made from the submersible, and sampling results, for three mud volcanoes of the caldera, Cheops, Chephren and Mykerinos show differences in activity but many common... |
| Tipo: Text |
Palavras-chave: Mediterranean Sea; Nile Deep Sea Fan; Mud volcano; Brine seep. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11089/10627.pdf |
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| Bayon, Germain; Loncke, L.; Dupre, Stephanie; Caprais, Jean-claude; Ducassou, E.; Duperron, Sebastien; Etoubleau, Joel; Foucher, Jean-paul; Fouquet, Yves; Gontharet, S.; Henderson, G. M.; Huguen, Caroline; Klaucke, I.; Mascle, J.; Migeon, S.; Olu-le-roy, Karine; Ondreas, Helene; Pierre, C.; Sibuet, Myriam; Stadnitskaia, A.; Woodside, J.. |
| We report on a multidisciplinary study of cold seeps explored in the Central Nile deep-sea fan of the Egyptian margin. Our approach combines in situ seafloor observation, geophysics, sedimentological data, measurement of bottom-water methane anomalies, pore-water and sediment geochemistry, and Th-230/U dating of authigenic carbonates. Two areas were investigated, which correspond to different sedimentary provinces. The lower slope, at similar to 2100 m water depth, indicates deformation of sediments by gravitational processes, exhibiting slope-parallel elongated ridges and seafloor depressions. In contrast, the middle slope, at similar to 1650 m water depth, exhibits a series of debris-flow deposits not remobilized by post-depositional gravity processes.... |
| Tipo: Text |
Palavras-chave: Authigenic carbonate; U Th; Cold seep; Continental margin; Nile. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6586.pdf |
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| Dupre, Stephanie; Mascle, Jean; Foucher, Jean-paul; Harmegnies, Francois; Woodside, John; Pierre, Catherine. |
| The Menes caldera is a fault-controlled depression (~8 km in diameter) at ~3,000 m water depth in the western province of the Nile deep-sea fan off NW Egypt, comprising seven mud volcanoes (MVs) of which two are active. Based on multichannel and chirp seismic data, temperature profiles, and high-resolution bathymetric data collected during the 2000 Fanil, 2004 Mimes and 2007 Medeco2 expeditions, the present study investigates factors controlling MV morphology, the geometry of feeder channels, and the origin of emitted fluids. The active Cheops and Chephren MVs are 1,500 m wide with subcircular craters at their summits, about 250 m in diameter, generally a few tens of metres deep, and filled with methane-rich muddy brines with temperatures reaching 42 °C... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00185/29668/28151.pdf |
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| Nouze, Herve; Cosquer, Emmanuel; Collot, Julien; Foucher, Jean-paul; Klingelhoefer, Frauke; Lafoy, Yves; Geli, Louis. |
| High-resolution reflection and refraction seismic data were collected in 2004 to investigate, in further detail than allowed by pre-existing low resolution seismic data, the nature of a Bottom Simulating Reflector (BSR) that extends over a broad area of the Fairway Basin, a rifted, continental structure located on the eastern flank of the Lord Howe Rise, to the southwest of New Caledonia. Two main reflectors are documented: the shallower (RN) mimics the seafloor and has a negative polarity while the deeper (RP) does not always mimic the seafloor and has a positive polarity. Using the existing regional seismic lines, we can show that reflector RN can be continuously followed up to DSDP 208 drill hole site. Reflector RP is discontinuous and cannot be traced... |
| Tipo: Text |
Palavras-chave: Stratigraphy; Gas hydrates; Geophysics; Southwest Pacific; Fairway Basin; BSR. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7321.pdf |
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| Foucher, Jean-paul; Le Pichon, Xavier. |
| Sleep (1971) has presented some very interesting observations on the exponential decrease of the subsidence rate in coastal basins. He shows that the time constant of this exponential decrease is of the same order of magnitude that the thermal time constant of a lithospheric plate. He then makes calculations with a physical model combining erosion and thermal contraction. The purpose of these comments is to show that his physical assumptions are invalid and that çonsequently his calculations are grossly in error. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1972 |
URL: http://archimer.ifremer.fr/doc/1972/publication-5041.pdf |
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| Auzende, Jean Marie; Boespflug, X; Bougault, Henri; Dosso, Laure; Foucher, Jean-paul; Joron, J-l; Ruellan, Etienne; Sibuet, Jean-claude. |
| Three cruises (POP 1, SEAPSO 3 and SEAPSO 4) carried out during the "Tour du Monde" of the R.V. Jean Charcot allow us to obtain new structural and geochemical data for the Okinawa, North Fiji and Lau basins. Taken together, the structural and geochemical data illustrate a difference in evolution stages of these sites. The less evolved stage is represented by the Okinawa basin, where accretion is evidence only by volcanic intrusion into a thinned continental crust. The most evolved stage is illustrated in the North Fiji basin, where the present-day accretion can be directly compared to the East Pacific Ridge. The Lau basin displays an intermediate stage with a complex system of accretionary ridges. This difference in the evolution stage is translated in the... |
| Tipo: Text |
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| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00268/37893/35974.pdf |
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| 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 |
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| Sultan, Nabil; Cochonat, Pierre; Foucher, Jean-paul; Mienert, J. |
| We present a theoretical study of the thermodynamic chemical equilibrium of gas hydrate in soil by taking into account the influence of temperature, pressure, pore water chemistry, and the mean pore size distribution. The model uses a new formulation based on the enthalpy form of the law of conservation of energy. The developed model shows that due to a temperature and pressure increase, hydrates may dissociate at the top of the hydrate occurrence zone to ensure a chemical equilibrium with the surrounding bulk water. This original result confirms what has been already shown through experiments. The second part of the paper presents an application of the model through a back-analysis of the giant Storegga Slide on the Norwegian margin. Two of the most... |
| Tipo: Text |
Palavras-chave: Storegga; Slope failure; GLE; Finite difference; Methane hydrate. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-699.pdf |
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| Nouze, Herve; Contrucci, Isabelle; Foucher, Jean-paul; Marsset, Bruno; Thomas, Yannick; Thereau, Estelle; Normand, Alain; Le Drezen, Eliane; Didailler, Stephane; Regnault, Jean-pierre; Le Conte, Sandie; Guidart, Stéphanie; Lekens, Win; Dean, Simon; Throo, Alexandre. |
| The Storegga slides, off Norway, are among the largest submarine slides ever known on a continental slope. The HYDRATECH cruise on N/O Le Suro (i) over capt aimed at a high-resolution survey of an area at the northern boundary of the slides. This survey images in great detail the bottom simulating reflector (BSR) extent and properties, the various fluid escape structures and the sediment deformations. The combination and the quality of the data help to understand the still poorly constrained relationships between fluid escapes, gas hydrates and slope stability in the survey area. |
| Tipo: Text |
Palavras-chave: Slope stability; Fluid escapes; Gas hydrates; Storegga. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-511.pdf |
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| Auzende, Jean-marie; Boespflug, Xavier; Bougault, Henri; Dosso, Laure; Foucher, Jean-paul; Joron, Jean-louis; Ruellan, Etienne; Sibuet, Jean-claude. |
| Three cruises (POP 1, SEAPSO 3 and SEAPSO 4) carried out during the "Tour du Monde" of the R.V. Jean Charcot allow us to obtain new structural and geochemical data for the Okinawa, North Fiji and Lau basins. Taken together, the structural and geochemical data illustrate a difference in evolution stages of these sites. The less evolved stage is represented by the Okinawa basin, where accretion is evidenced only by volcanic intrusion into a thinned continental crust. The most evolved stage is illustrated in the North Fiji basin, where the present-day accretion can be directly compm·ed to the East Pacific Ridge. The Lau basin displays an intem1ediate stage with a complex system of accretionary ridges. This difference in the evolution stage is translated in... |
| Tipo: Text |
Palavras-chave: Ouest Pacifique; Bassins arriere arc; Structure; Accretion; Geochimie; West Pacific; Back arc basins; Structure; Accretion; Geochemistry. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00119/23058/20893.pdf |
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| Omoregie, E; Mastalerz, V; De Lange, G; Straub, K; Kappler, A; Roy, H; Stadnitskaia, A; Foucher, Jean-paul; Boetius, A. |
| In this study we determined the composition and biogeochemistry of novel, brightly colored, white and orange microbial mats at the surface of a brine seep at the outer rim of the Chefren mud volcano. These mats were interspersed with one another, but their underlying sediment biogeochemistries differed considerably. Microscopy revealed that the white mats were granules composed of elemental S filaments, similar to those produced by the sulfide-oxidizing epsilonproteobacterium "Candidatus Arcobacter sulfidicus." Fluorescence in situ hybridization indicated that microorganisms targeted by a "Ca. Arcobacter sulfidicus"-specific oligonucleotide probe constituted up to 24% of the total the cells within these mats. Several 16S rRNA gene sequences from organisms... |
| Tipo: Text |
Palavras-chave: Gulf of mexico; Sulfate reducing bacteria; Egyptian continental margin; Northeast pacific ocean; Ribosomal rna sequences; In situ hybridization; Anaerobic oxidation; Marine sediments; Gas hydrate; Oxiding bacteria. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6201.pdf |
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| Sibuet, Jean-claude; Mathis, B; Pastouret, Léo; Auzende, Jean-marie; Foucher, Jean-paul; Hunter, Peter; Guennoc, P; De Graciansky, Pc; Montadert, L; Masson, Douglas. |
| Tipo: Text |
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| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/00184/29494/27815.pdf |
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| Registros recuperados: 29 | |
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