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| Registros recuperados: 67 | |
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| De Prunele, Alexis; Ruffine, Livio; Riboulot, Vincent; Peters, Carl A.; Croguennec, Claire; Guyader, Vivien; Pape, Thomas; Bollinger, Claire; Bayon, Germain; Caprais, Jean-claude; Germain, Yoan; Donval, Jean-pierre; Marsset, Tania; Bohrmann, Gerhard; Geli, Louis; Rabiu, Abdulkarim; Lescanne, Marc; Cauquil, Eric; Sultan, Nabil. |
| The Niger Delta is one of the largest hydrocarbon basin offshore Africa and it is well known for the presence of active pockmarks on the seabed. During the Guineco-MeBo cruise in 2011, long cores were taken from a pockmark cluster in order to investigate the state of its current activity. Gas hydrates, oil and pore-water were sampled for geochemical studies. The resulting dataset combined with seismic data reveal that shallow hydrocarbon migration in the upper sedimentary section was focused exclusively within the pockmarks. There is a clear tendency for gas migration within the hydrate-bearing pockmarks, and oil migration within the carbonate-rich one. This trend is interpreted as a consequence of hydrate dissolution followed by carbonate precipitation... |
| Tipo: Text |
Palavras-chave: Anaerobic oxidation of methane; Cluster of pockmarks; Fluid flow; Gas hydrates; Pore-water profiles; Transient state. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00365/47647/47676.pdf |
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| Bodennec, Guy; Pignet, Patricia; Caprais, Jean-claude. |
| A la suite du naufrage du pétrolier Tanio, le 7 mars 1980, l'équipe Chimie du Département ELGMM/COB a participé à différentes campagnes océanographiques et de terrain, principalement dans le secteur compris entre les baies de Lannion et de St Brieuc, pour : 1°) Evaluer le degré de contamination de l'eau de mer et des sédiments subtidaux, 2°) Suivre le processus de dégradation du pétrole piégé à la côte, suivant la nature sédimentologique et la situation géographique du site de prélèvement. Ce rapport complète les précédents compte-rendus de mission, en rassemblant les résultats acquis au cours d'un suivi chimique effectué entre les mois de mars et de juin 1980 pour suivre la cinétique de décontamination de l'eau, et entre les mois de mars 1980 et juillet... |
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| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00081/19229/16824.pdf |
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| Ruffine, Livio; Caprais, Jean-claude; Bayon, Germain; Riboulot, Vincent; Donval, Jean-pierre; Etoubleau, Joel; Birot, Dominique; Pignet, Patricia; Rongemaille, Emmanuelle; Chazallon, Bertrand; Grimaud, Sylvie; Adamy, Jerome; Charlou, Jean-luc; Voisset, Michel. |
| A joint industrial project with IFREMER and Total provides insights into the tectonic setting and the geochemistry of a large active pockmark offshore W-Africa in the Niger Delta. The study combines both geophysical (seismic) and geochemical data to infer the dynamics of a 300 m wide pockmark located at 667 m water depth. Two Calypso cores, one at the centre and one outside the pockmark, along with three box-cores, two inside the pockmark and one outside, were collected to study the geochemistry of gas hydrates, carbonates and pore waters. Two seismic lines, a 3D high resolution random line and a 2D high resolution seismic line, provide a good description of the plumbing of the system. The integrated results depict a very active pockmark characterized by... |
| Tipo: Text |
Palavras-chave: Active pockmark; Anaerobic oxidation of methane; Gas hydrates; Carbonates; Seismic surveys; Fault system; U/Th dating. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00139/24981/23102.pdf |
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| Sarradin, Pierre-marie; Caprais, Jean-claude; Riso, Ricardo; Kerouel, Roger; Aminot, Alain. |
| Water samples were collected around the communities of a hydrothermal mussel, Bathymodiolus sp., in the Lucky Strike (1700 m depth) and Menez Gwen (850 m depth) areas, Mid Atlantic Ridge, and analysed for chemical constituents. The environment surrounding the organisms consists in sea water (88 to 100%) mixed with hydrothermal fluid with pH between 6.2 and 8, Sigma S (H2S + HS-) concentrations from 0 to 62 mu mol l(-1). High dissolved organic carbon (DOC) concentrations suggest a highly productive ecosystem. Production of ammonium and DOG, consumption of nitrate and sulfide in the vicinity of the organisms are among the environmental changes found in relation with local biological activity. Concentrations of Cu and Pb were high, implying that the organisms... |
| Tipo: Text |
Palavras-chave: Environment; Sea water; Hydrothermal vents; Mussels. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00147/25847/23968.pdf |
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| Caprais, Jean-claude; Marchand, Michel. |
| The use of glass capillary columns in gas-liquid chromatography, to identify high weight molecular organochlorine compounds, greatly improve the capacity of separation of the different detected compounds, specially between PCB residues and sorne chlorinated insectieides (dieldrin, DDT and metabolites). A comparison is given between chromatographie results obtained with glass capillary columns and classical columns. |
| Tipo: Text |
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| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00186/29770/28213.pdf |
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| Olu, Karine; Caprais, Jean-claude; Fifis, Alexis; Fabri, Marie-claire; Galeron, Joelle; Budzinsky, H; Le Menach, K; Khripounoff, Alexis; Ondreas, Helene; Sibuet, Myriam. |
| A giant pockmark colonised by dense cold-seep assemblages near 3160 m depth along the Congo-Angola margin has been surveyed by the ROV Victor 6000. The quantitative distribution of chemosynthetic communities was mapped along the dive tracks from a video study using GIS and image mosaicking. Several types of faunal assemblages, either dominated by bivalves of the families Mytilidae (Bathmodiolus sp.) Vesicom idae (Calyptogena sp., 'Vesicomya' aff. chuni), or by Siboglinidae polychaetes (Escarpia southwardae) were mapped over the 800-m diameter pockmark area and sampled for fauna, water and sediment. The isotopic analyses (delta C-13) of tissues from symbiont-bearing species were within the range typical of nutrition via symbiosis using methane for mussels... |
| Tipo: Text |
Palavras-chave: Symbiont bearing species; Spatial distribution; Methane; Megafauna; Cold seeps. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2681.pdf |
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| Shillito, B; Le Bris, Nadine; Hourdez, S; Ravaux, J; Cottin, D; Caprais, Jean-claude; Jollivet, D; Gaill, F. |
| The shrimp Mirocaris fortunata is a hydrothermal vent species that is found at most vent-sites along the Mid-Atlantic Ridge. This endemic species is found across a hydrothermal gradient, with thermal conditions ranging from 2-9 degrees C in ambient seawater to fairly warm values of about 25 degrees C. We performed in vivo experiments on M. fortunata specimens originating from different sites and depths (850 m to 2300 m), both at atmospheric pressure and in pressurized aquaria, to characterise the upper thermal limits of this species. Atmospheric pressure results show that thermal physiology should be studied at each population's native pressure. At in situ pressure, shrimps from Menez Gwen (850 m depth) and Lucky Strike (1700 m depth) do not survive... |
| Tipo: Text |
Palavras-chave: IPOCAMP TM; Crustacea; Mirocaris fortunata; Thermal stress; Hydrothermal vent. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1240.pdf |
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| Rabouille, C.; Caprais, Jean-claude; Lansard, B.; Crassous, Philippe; Dedieu, K.; Reyss, J. L.; Khripounoff, Alexis. |
| A study of organic carbon mineralization from the Congo continental shelf to the abyssal plain through the Congo submarine channel and Angola Margin was undertaken using in situ measurements of sediment oxygen demand as a tracer of benthic carbon recycling. Two measurement techniques were coupled on a single autonomous platform: in situ benthic chambers and microelectrodes, which provided total and diffusive oxygen uptake as well as oxygen microdistributions in porewaters. In addition, sediment trap fluxes, sediment composition (Org-C, Tot-N, CaCO3, porosity) and radionuclide profiles provided measurements of, respectively input fluxes and burial rate of organic and inorganic compounds. The in situ results show that the oxygen consumption on this margin... |
| Tipo: Text |
Palavras-chave: Sediment carbon budget; Organic carbon burial; Congo Submarine Canyon; Organic carbon recycling in sediments; In situ oxygen demand. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7316.pdf |
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| Sarradin, Pierre-marie; Caprais, Jean-claude. |
| This preliminary study presents a new method for the determination of dissolved gases in sea-water. After headspace extraction, gaseous compounds are separated by GC on a dual column adsorption system, The individual species are thereafter eluted to three different detectors (thermal conductivity, flame ionization and FPD) using a second switching valve, The analysis is quantitative for methane and carbon dioxide with limits of determination of 0.1 and 50 mu mol l(-1), respectively, and corresponding standard deviations of 4 and 7%, and has been applied to deep sea hydrothermal samples, Further optimization is necessary to allow the quantitative determination of hydrogen sulfide, nitrogen, oxygen and carbon monoxide. |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00186/29766/28198.pdf |
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| Khripounoff, Alexis; Caprais, Jean-claude; Le Bruchec, Julie; Rodier, Philippe; Noel, Philippe; Cathalot, Cecile. |
| The submarine canyons of the Brittany continental slope (Bay of Biscay–Northeast Atlantic) were studied to describe the conditions in which cold-water corals occur in these areas and their consequences for coral metabolism. Near-bottom current, oxygen, temperature, and particle flux, simultaneously measured for 2 yr at 850 m depth, revealed by spectral analysis the presence of several frequencies with a dominant semidiurnal tidal cycle and a current direction determined exclusively by the canyon topography. Sediment trap data also showed a seasonal input of material with a large peak of particles and carbon fluxes at the end of winter. Daily particle and carbon fluxes at 20 m above the bottom were 2.49 g m−2 d−1 and 20 mg C m−2 d−1, respectively. At the... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28380/26695.pdf |
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| Khripounoff, Alexis; Caprais, Jean-claude; Decker, Carole; Essirard, Mikael; Le Bruchec, Julie; Noel, Philippe; Olu, Karine. |
| We have studied two species of vesicomyid bivalves inhabiting different areas of sulfide-rich sediments in association with methane seepage at two pockmarks located at about 650 m and 3150 m depth, respectively, along the Gabon-Congo margin, and organic-rich sediments in the deepest zone (4950 m depth) of the Congo deep-sea fan. Benthic chambers Calmar were deployed on three study sites to assess gas and solute exchanges at the water-sediment interface. We recorded in situ measurements of oxygen, total carbon dioxide, ammonium, methane, and sulfide in two clam beds at each site. At all sites, irrespective of which the vesicomyid species are present, oxygen consumption was high and variable (28–433 mmol m−2 d−1) as was total carbon dioxide emission (36–1857... |
| Tipo: Text |
Palavras-chave: Benthic chamber; Cold-seep ecosystem; Reduced sediment; Gas fluxes; Vesicomyid bivalves; Gulf of Guinea. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00226/33746/32160.pdf |
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Mesure des sulfures dans les eaux et eaux interstitielles : CT, MTB, Calypso, Calmar, RAP, PEP. Campagne Congolobe, Golfe de Guinée, Stations : Regab, A, F, C, B, E, Guiness. Mesure par spectrophotométrie
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ArchiMer | |
| Caprais, Jean-claude; Le Bruchec, Julie. |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00172/28363/26654.pdf |
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| Duperron, Sebastien; Nadalig, Thierry; Caprais, Jean-claude; Sibuet, Myriam; Fiala Medioni, Aline; Amann, Rudolf; Dubilier, Nicole. |
| Deep-sea mussels of the genus Bathymodiolus (Bivalvia: Mytilidae) harbor symbiotic bacteria in their gills and are among the dominant invertebrate species at cold seeps and hydrothermal vents. An undescribed Bathymodiolus species was collected at a depth of 3,150 m in a newly discovered cold seep area on the southeast Atlantic margin, close to the Zaire channel. Transmission electron microscopy, comparative 16S rRNA analysis, and fluorescence in situ hybridization indicated that this Bathymodiolus sp. lives in a dual symbiosis with sulfide- and methane-oxidizing bacteria. A distinct distribution pattern of the symbiotic bacteria in the gill epithelium was observed, with the thiotrophic symbiont dominating the apical region and the methanotrophic symbiont... |
| Tipo: Text |
Palavras-chave: Gabon; Southeast Atlantic; Methane seep; Hydrothermal vent; Deep sea; RRNA analysis; Methane concentration; Gill epithelium; Symbiosis; Bacteria; Mytilidae. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1266.pdf |
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| Bayon, Germain; Henderson, Gideon M.; Etoubleau, Joel; Caprais, Jean-claude; Ruffine, Livio; Marsset, Tania; Dennielou, Bernard; Cauquil, Eric; Voisset, Michel; Sultan, Nabil. |
| The application of uranium-thorium dating methods to authigenic carbonates provides unique constraints on the temporal evolution of methane seeps at ocean margins. In this study, we report U-Th isotope measurements for carbonate breccias collected from within a hydrate-bearing pockmark located at the Niger Delta margin. These concretions were extracted from a carbonate-rich layer in the upper two meters of a sediment core (N2-KS-44; ~ 1200 m water depth), well above the present-day sulphate-methane transition zone (about 3 m depth) and the presence of gas hydrates in the sediment. The stratigraphy of core N2-KS-44 was established by tuning its downcore Al/Ti profile to a well-dated nearby reference core, and carbonate 230Th/U ages were calculated using... |
| Tipo: Text |
Palavras-chave: Gas hydrates; Pockmarks; U-series; Authigenic carbonates; Niger delta. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00286/39708/41518.pdf |
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| Portail, Marie; Olu, Karine; Escobar-briones, E.; Caprais, Jean-claude; Menot, Lenaick; Waeles, Mathieu; Cruaud, Perrine; Sarradin, Pierre-marie; Godfroy, Anne; Sarrazin, Jozee. |
| Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of a biogeographic barrier, and comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem-specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep- and vent-common abiotic... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00280/39076/37642.pdf |
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| Olu, Karine; Decker, Carole; Pastor, Lucie; Caprais, Jean-claude; Khripounoff, Alexis; Morineaux, Marie; Ain Baziz, M.; Menot, Lenaick; Rabouille, C.. |
| Methane-rich fluids arising from organic matter diagenesis in deep sediment layers sustain chemosynthesis-based ecosystems along continental margins. This type of cold seep develops on pockmarks along the Congo margin, where fluids migrate from deep-buried paleo-channels of the Congo River, acting as reservoirs. Similar ecosystems based on shallow methane production occur in the terminal lobes of the present-day Congo deep-sea fan, which is supplied by huge quantities of primarily terrestrial material carried by turbiditic currents along the 800 km channel, and deposited at depths of up to nearly 5000 m. In this paper, we explore the effect of this carbon enrichment of deep-sea sediments on benthic macrofauna, along the prograding lobes fed by the current... |
| Tipo: Text |
Palavras-chave: Chemosynthesis-based ecosystems; Cold seeps; Organic rich sediments; Macrofaunal communities. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00384/49561/50053.pdf |
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| Loncke, L.; Maillard, A.; Basile, C.; Roest, Walter; Bayon, Germain; Gaullier, V.; Pattier, France; Mercier De Lépinay, Marion; Grall, Celine; Droz, L.; Marsset, Tania; Giresse, P.; Caprais, Jean-claude; Cathalot, Cecile; Graindorge, D.; Heuret, A.; Lebrun, J. F.; Bermell, Sylvain; Marcaillou, B.; Sotin, C.; Hebert, B.; Patriat, Martin; Bassetti, M. A.; Tallobre, Cedric; Buscail, R.; Durrieu De Madron, X.; Bourrin, F.. |
| he IGUANES cruise took place in May 2013 on the R/V L'Atalante along the Demerara passive transform margin off French Guiana and Surinam. Seismic, multibeam and chirp acquisitions were made. Piston cores were collected for pore geochemistry and sedimentology. A mooring was deployed on the sea-bottom for 10 months (temperature, salinity, turbidity and current measurements). This new dataset highlights the lateral variability of the 350 km-long Guiana–Surinam transform margin due to the presence of a releasing bend between two transform segments. The adjacent Demerara Plateau is affected by a 350 km-long giant slide complex. This complex initiated in Cretaceous times and was regularly reactivated until recent times. Since the Miocene, contourite processes... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00428/53942/55285.pdf |
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| Registros recuperados: 67 | |
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