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| Registros recuperados: 15 | |
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| Caley, Thibaut; Giraudeau, Jacques; Malaize, Bruno; Rossignol, Linda; Pierre, Catherine. |
| Heat and salt transfer from the Indian Ocean to the Atlantic Ocean (Agulhas leakage) has an important effect on the global thermohaline circulation and climate. The lack of long transfer record prevents elucidation of its role on climate changes throughout the Quaternary. Here, we present a 1,350-ka accumulation rate record of the planktic foraminiferal species Globorotalia menardii. We demonstrate that, according to previous assumptions, the presence and reseeding of this fauna in the subtropical southeast Atlantic was driven by interocean exchange south of Africa. The Agulhas transfer strengthened at glacial ice-volume maxima for every glacial-interglacial transition, with maximum reinforcements organized according to a 400-ka periodicity. The long-term... |
| Tipo: Text |
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| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00265/37658/36513.pdf |
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| Pierre, Catherine; Fouquet, Yves. |
| Submersible investigations with the ROV Victor 6000 of some pockmark structures on the seafloor of the Congo deep-sea fan have shown that they are active venting sites of methane-rich fluids, associated with abundant fauna and carbonate crusts. Moreover, methane hydrates have been observed both outcropping and deep in the sediments in the centre of the "Regab" giant pockmark. Authigenic carbonates, mostly calcite sometimes mixed with aragonite, are cementing the sedimentary matrix components and fauna; diatoms are abundant but only as moulds, indicating that biogenic silica dissolution occurred in situ synchronous with carbonate precipitation. The occurrence of diagenetic barite and pyrite in some carbonate crusts demonstrates that they can be formed... |
| Tipo: Text |
Palavras-chave: Oxygen isotopes; Carbon isotopes; Congo deep sea fan; Gas hydrate; Methane seep; Authigenic carbonate. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2608.pdf |
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| Pierre, Catherine; Bayon, Germain; Blanc-valleron, Marie-madeleine; Mascle, Jean; Dupre, Stephanie. |
| On the passive margin of the Nile deep-sea fan, the active Cheops mud volcano (MV; ca. 1,500 m diameter, ~20–30 m above seafloor, 3,010–3,020 m water depth) comprises a crater lake with hot (up to ca. 42 °C) methane-rich muddy brines in places overflowing down the MV flanks. During the Medeco2 cruise in fall 2007, ROV dives enabled detailed sampling of the brine fluid, bottom lake sediments at ca. 450 m lake depth, sub-surface sediments from the MV flanks, and carbonate crusts at the MV foot. Based on mineralogical, elemental and stable isotope analyses, this study aims at exploring the origin of the brine fluid and the key biogeochemical processes controlling the formation of these deep-sea authigenic carbonates. In addition to their patchy occurrence in... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00186/29735/28189.pdf |
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| Ritt, Benedicte; Pierre, Catherine; Gauthier, Olivier; Wenzhoefer, Frank; Boetius, Antje; Sarrazin, Jozee. |
| The Nile Deep-Sea Fan (NDSF) is located on the passive continental margin off Egypt and is characterized by the occurrence of active fluid seepage such as brine lakes, pockmarks and mud volcanoes. This study characterizes the structure of faunal assemblages of such active seepage systems of the NDSF. Benthic communities associated with reduced, sulphidic microhabitats such as sediments and carbonate crusts were sampled by remotely operated vehicles during two cruises in 2006 (BIONIL) and 2007 (MEDECO). Environmental conditions and biological factors including family-level faunal composition, density and diversity were measured at local and regional scales. Significant differences were detected at different spatial scales: (1) the fauna of reduced habitats... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00037/14798/12212.pdf |
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| Ritt, Benedicte; Sarrazin, Jozee; Caprais, Jean-claude; Noel, Philippe; Gauthier, Olivier; Pierre, Catherine; Henry, Pierre; Desbruyeres, Daniel. |
| A brackish-water cold seep on the North Anatolian Fault (NAF) in the Marmara Sea was investigated with the Nautile submersible during the MarNaut cruise in 2007. This active zone has already been surveyed and revealed evidence of active seeping on the seafloor, such as bubble emissions, patches of reduced sediments, microbial mats and authigenic carbonate crusts. MarNaut was the first opportunity to sample benthic communities in the three most common microhabitats (bioturbated and reduced sediments, carbonate crust) and to examine their relationships with environmental conditions. To do so, faunal communities were sampled and chemical measurements were taken close to the organisms. According to diversity indices, the bioturbated microhabitat exhibited the... |
| Tipo: Text |
Palavras-chave: Marmara Sea; Cold seep; Benthic fauna; Biological diversity; Environmental conditions; Chemosynthetic. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12506/9528.pdf |
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| Bayon, Germain; Dupre, Stephanie; Ponzevera, Emmanuel; Etoubleau, Joel; Cheron, Sandrine; Pierre, Catherine; Mascle, Jean; Boetius, Antje; De Lange, Gert J.. |
| Marine sediments at ocean margins vent substantial amounts of methane(1,2). Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems(3,4). The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid over geological time remain poorly constrained. Here, we characterize the petrology and geochemistry of rocks sampled from metre-size build-ups of methane-derived carbonate chimneys located at the Amon mud volcano on the Nile deep-sea fan. We find that these carbonates comprise porous structures composed of aggregated spherules of aragonite, and closely resemble microbial carbonate reefs forming at present... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00156/26734/24854.pdf |
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| Hensen, Christian; Duarte, Joao C.; Vannucchi, Paola; Mazzini, Adriano; Lever, Mark A.; Terrinha, Pedro; Géli, Louis; Henry, Pierre; Villinger, Heinrich; Morgan, Jason; Schmidt, Mark; Gutscher, Marc-andre; Bartolome, Rafael; Tomonaga, Yama; Polonia, Alina; Gràcia, Eulàlia; Tinivella, Umberta; Lupi, Matteo; Çağatay, M. Namık; Elvert, Marcus; Sakellariou, Dimitris; Matias, Luis; Kipfer, Rolf; Karageorgis, Aristomenis P.; Ruffine, Livio; Liebetrau, Volker; Pierre, Catherine; Schmidt, Christopher; Batista, Luis; Gasperini, Luca; Burwicz, Ewa; Neres, Marta; Nuzzo, Marianne. |
| Marine transform faults and associated fracture zones (MTFFZs) cover vast stretches of the ocean floor, where they play a key role in plate tectonics, accommodating the lateral movement of tectonic plates and allowing connections between ridges and trenches. Together with the continental counterparts of MTFFZs, these structures also pose a risk to human societies as they can generate high magnitude earthquakes and trigger tsunamis. Historical examples are the Sumatra-Wharton Basin Earthquake in 2012 (M8.6) and the Atlantic Gloria Fault Earthquake in 1941 (M8.4). Earthquakes at MTFFZs furthermore open and sustain pathways for fluid flow triggering reactions with the host rocks that may permanently change the rheological properties of the oceanic... |
| Tipo: Text |
Palavras-chave: Transform faults; Fractures zones; Coupling of seismicity and fluid flow; Microbial life; Heat flow; Fluid geochemistry; Seafloor observation systems; Seismic precursors. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60085/63422.pdf |
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| Henry, Pierre; Tryon, Mike; Bourlange, Sylvain; Geli, Louis; Zitter, Tiphaine; Bouloubassi, Ioanna; Burnard, Pete; Cagatay, M Namik; Chevalier, Nicolas; Gasperini, Luca; Gorur, Naci; Gerigk, Christoph; Leveque, Claude; Le Pichon, Xavier; Lopez-garcia, Purification; Massol, Alain; Mercier De Lepinay, Bernard; Natalin, Boris; Ozeren, Sinan; Pierre, Catherine; Ritt, Benedicte; Sengor, Am Celal; Ucarkus, Gulsen. |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00398/50962/51714.pdf |
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| Pierre, Catherine; Mascle, Jean; Dupre, Stephanie. |
| The MEDECO Leg 2 cruise followed the MEDECO Leg 1 cruise that had crossed the Mediterranean Sea from the west to the east to study benthic communities of the Var canyon, deep corals found on the Calabrian Margin and cold seep ecosystems of the Mediterranean Ridge. The main objective of the MEDECO Leg 2 cruise was to study and compare, using a multidisciplinary approach, the structure and dynamics of deep-sea ecosystems at various active cold seep sites from the Nile deep sea fan and the Calabrian Arc, in the Eastern Mediterranean sea. During MEDECO Legs 1 & 2, a multiscale strategy was promoted to integrate (1) a high resolution cartography of geological structures (km2 scale), (2) a detailed mapping, including video imagery, of smaller-scale areas... |
| Tipo: Text |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00134/24550/22583.pdf |
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| Ruffine, Livio; Ondreas, Helene; Blanc-valleron, Marie-madeleine; Teichert, Barbara M. A.; Scalabrin, Carla; Rinnert, Emmanuel; Birot, Dominique; Croguennec, Claire; Ponzevera, Emmanuel; Pierre, Catherine; Donval, Jean-pierre; Alix, Anne-sophie; Germain, Yoan; Bignon, Laurent; Etoubleau, Joel; Caprais, Jean-claude; Knoery, Joel; Lesongeur, Francoise; Thomas, Bastien; Roubi, Angelique; Legoix, Ludovic Nicolas; Burnard, Pete; Chevalier, Nicolas; Lu, Hailong; Dupre, Stephanie; Fontanier, Christophe; Dissard, Delphine; Olgun, Nazli; Yang, Hailin; Strauss, Harald; Ozaksoy, Volkan; Perchoc, Jonathan; Podeur, Christian; Tarditi, Corinne; Ozbeki, Eyyup; Guyader, Vivien; Marty, Bernard; Madre, David G; Pitel-roudaut, Mathilde; Grall, Celine; Embriaco, Davide; Polonia, Mina; Gasperini, Lucas; Cagatay, M. Namik; Henry, Pierre; Geli, Louis. |
| MarsiteCruise was undertaken in October/November 2014 in the Sea of Marmara to gain detailed insight into the fate of fluids migrating within the sedimentary column and partially released into the water column. The overall objective of the project was to achieve a more global understanding of cold-seep dynamics in the context of a major active strike-slip fault. Five remotely operated vehicle (ROV) dives were performed at selected areas along the North Anatolian Fault and inherited faults. To efficiently detect, select and sample the gas seeps, we applied an original procedure. It combines sequentially (1) the acquisition of ship-borne multibeam acoustic data from the water column prior to each dive to detect gas emission sites and to design the tracks of... |
| Tipo: Text |
Palavras-chave: Acoustic survey; Authigenic carbonates; Biogeochemistry; Chemical analyses; Cold seeps; Dissolved major elements; Fluid seepage; Geology; In situ Raman analysis; Methane; ROV dives. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00433/54434/55783.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; 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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| Registros recuperados: 15 | |
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