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| Registros recuperados: 55 | |
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| Jean Baptiste, P; Fourre, E; Dapoigny, A; Charlou, Jean-luc; Donval, Jean-pierre. |
| As part of a multidisciplinary project aimed at studying mid-ocean ridge processes near the Azores, fifty water column profiles were analyzed for He-3/He-4 ratios in dissolved helium (a well-known hydrothermal tracer) from 36 degrees N to 40 degrees N along the Mid-Atlantic Ridge (MAR) and over the Azores Plateau. As expected, large delta(3) He anomalies could be observed over the Rainbow, Lucky Strike, and Menez Gwen hydrothermal sites. The main finding of the present study is the discovery of a large hydrothermal 3 He plume north of the Acor Fracture Zone (north AFZ site), with a CH4/He-3 ratio indicative of a basaltic-hosted hydrothermal system. Clear He-3 and CH4 anomalies, likely corresponding to unknown venting sites too, were also detected in the... |
| Tipo: Text |
Palavras-chave: Hydrothermal processes; Helium 3; Mid ocean ridges. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3876.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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| Ondreas, Helene; Olu, Karine; Fouquet, Yves; Charlou, Jean-luc; Gay, Aurelien; Dennielou, Bernard; Donval, Jean-pierre; Fifis, Alexis; Nadalig, Thierry; Cochonat, Pierre; Cauquil, E; Bourillet, Jean-francois; Le Moigne, Morgan; Sibuet, Myriam. |
| A giant, 800-m wide pockmark, called Regab, was discovered along the Equatorial African margin at 3160-m water depth and was explored by remote operated vehicle (ROV) as part of the Zaiango (1998-2000) and Biozaire (2001-2003) projects carried out conjointly by TOTAL and a number of French research institutes. A microbathymetric map obtained using the ROV sensors shows that the pockmark actually consists of a cluster of smaller pockmarks aligned N70 along a 15-m deep depression. Methane was recorded all over the pockmark, the highest values along the axis of the depression where massive carbonate crusts and dense seep communities were also found. Several faunal species belong to the Vesicomyidae and Mytilidae bivalve families, as well as to Siboglinidae... |
| Tipo: Text |
Palavras-chave: Gabon; Microbathymetric map; ROV; Exploration; Pockmark; Equatorial African margin. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1239.pdf |
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| German, C. R.; Thurnherr, A. M.; Knoery, Joel; Charlou, Jean-luc; Jean-baptiste, P.; Edmonds, H. N.. |
| High-temperature hydrothermal activity occurs in all ocean basins and along ridge crests of all spreading rates. While it has long been recognized that the fluxes associated with such venting are large, precise quantification of their impact on ocean biogeochemistry has proved elusive Here, we report a comprehensive study of heat, fluid and chemical fluxes from a single submarine hydrothermal field. To achieve this, we have exploited the integrating nature of the non-buoyant plume dispersing above the Rainbow hydrothermal field, a long-lived and tectonically hosted high-temperature vent site on the Mid-Atlantic Ridge. Our calculations yield heat and volume fluxes for high-temperature fluids exiting the seafloor of similar to 0.5 GW and 450 Ls(-1), together... |
| Tipo: Text |
Palavras-chave: Hydrothermal fluxes; Biogeochemistry; Rainbow vent-field. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11423/8040.pdf |
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| Bougault, Henri; Appriou, P; Bienvenu, P; Cambon, Pierre; Charlou, Jean-luc; Collette, B; Donval, Jean-pierre; Dosso, Laure; Floch, G; Fouquet, Yves. |
| Tipo: Text |
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| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00070/18105/15653.pdf |
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| Roussel, Erwan; Konn, Cecile; Charlou, Jean-luc; Donval, Jean-pierre; Fouquet, Yves; Querellou, Joel; Prieur, Daniel; Cambon-bonavita, Marie-anne. |
| The distribution of Archaea and methanogenic, methanotrophic and sulfate-reducing communities in three Atlantic ultramafic-hosted hydrothermal systems (Rainbow, Ashadze, Lost City) was compared using 16S rRNA gene and functional gene (mcrA, pmoA and dsrA) clone libraries. The overall archaeal community was diverse and heterogeneously distributed between the hydrothermal sites and the types of samples analyzed (seawater, hydrothermal fluid, chimney and sediment). The Lost City hydrothermal field, characterized by high alkaline warm fluids (pH>11; T<95 °C), harbored a singular archaeal diversity mostly composed of unaffiliated Methanosarcinales. The archaeal communities associated with the recently discovered Ashadze 1 site, one of the deepest active... |
| Tipo: Text |
Palavras-chave: Archaea; Hydrothermal vent; Mid-Atlantic Ridge; 16S rRNA gene; Sediment; Ultramafic. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00067/17836/15573.pdf |
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| Mugler, C.; Jean-baptiste, P.; Perez, Florian; Charlou, Jean-luc. |
| The production of hydrogen by serpentinization in ultramafic-hosted hydrothermal systems is simulated by coupling thermodynamic and dynamic modeling in the framework of a thermo-hydraulic single-pass model where a high-temperature hydrothermal fluid moves preferentially through a main canal of high permeability. The alteration of ultramafic rocks is modeled with a first-order kinetic formulation, wherein the serpentinization rate coefficient, Kr, takes the form: Kr = A exp(−α(T − T0)2). In this formulation, α determines the temperature range of the reaction and T0 is the temperature at which the serpentinization rate reaches its maximum. This model is applied to the Rainbow hydrothermal system, which is situated on the Mid-Atlantic Ridge, and characterized... |
| Tipo: Text |
Palavras-chave: First-order kinetic law; Hydrothermal system; Rainbow vent site; Reaction rate; Serpentinization. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00314/42514/41906.pdf |
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| Gay, Aurelien; Lopez, M; Ondreas, Helene; Charlou, Jean-luc; Sermondadaz, G; Cochonat, Pierre. |
| The origin of the cold fluid venting from a Giant Pockmark within the Lower Congo Basin has been elucidated based upon results of precise mapping, submersible dives, gravity coring and isotopic analyses realized under a TOTAL-IFREMER cooperative project (ZAIANGO and BIOZAIRE projects). During four dives of the IFREMER ROV-Victor 6000, the bottom was filmed, hard and soft samples were lifted from the sediment, and water samples were collected with a CTD-rosette system. The detailed dip map shows that the 800 in wide Giant Pockmark is a composite feature due to the coalescence of multiple 100 in wide depressions that displays a broad range of biological, mineralogical and chemical features on the seafloor, leading to a seafloor anomaly recorded on the... |
| Tipo: Text |
Palavras-chave: BIOZAIRE; ZAIANGO; Palaeochannel; Hydrates; Chemosynthesis; Seafloor facies; Fluid migration; Pockmark. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1114.pdf |
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| Fouquet, Yves; Pelleter, Ewan; Konn, Cecile; Chazot, Gilles; Dupre, Stephanie; Alix, Anne-sophie; Cheron, Sandrine; Donval, Jean-pierre; Guyader, Vivien; Etoubleau, Joel; Charlou, Jean-luc; Labanieh, Shasa; Scalabrin, Carla. |
| The study area is located at the transition between the northern end of the Tonga Trench and the North Fiji fracture zone, where tectonic movements are reputed to be the fastest in the world. To the southeast of Futuna Island, a broad area of volcanism occurs within a region characterized by a change in the tectonic fabric between a NE-SW oriented volcanic graben and the N-S oriented Alofi ridge. In 2010, the active volcano Kulo Lasi, which represents the most recent volcanic episode in the Futuna area, was discovered in the center of this extensive volcanic zone. Kulo Lasi is a 20 km diameter shield volcano that rises 400 m above the seafloor. It is composed of basaltic to trachy-andesitic lava with no obvious geochemical affinity with the Tonga... |
| Tipo: Text |
Palavras-chave: Subaqueous volcanism; Hydrothermal activity; Kulo Lasi caldera; Sulfides; SW Pacific. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55633/57279.pdf |
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| Auzende, Jean-marie; Ishibashi, J; Beaudouin, Y; Charlou, Jean-luc; Delteil, J; Donval, Jean-pierre; Fouquet, Yves; Gouillou, Jp; Ildefonse, B; Kimura, H; Nishio, Y; Knoery, Joel; Ruollan, E. |
| In 1995, a joint French‐Japanese cruise (ManusFlux) explored the Manus Spreading Center and some sites of the South Eastern Rift in the Manus Basin off the coast of Papua New Guinea (Figure 1) with the Japanese submersible [Auzende et al., 1996; Gamo et al., 1997]. In the framework of this joint project, called New STARMER, the French and Japanese teams completed the Manaute cruise with the R/V LAtalante and the Ifremer submersible Nautile in April and May 2000. The Manaute cruise explored and sampled volcanic and hydrothermal sites in the eastern part of Manus Basin and on the spreading axis of the Western Ridge (WR). The eastern part of the Manus Basin (Figure 2) was interpreted as a stretched‐back arc basin crust showing alternatively elongated ridges... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00069/18055/15597.pdf |
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| Bougault, Henri; Appriou, P; Birolleau, A; Charlou, Jean-luc; Crane, K; Etoubleau, Joel; Fouquet, Yves; Gente, P; Harmegnies, Francois; Landure, Jean-yves; Le Noac'H, A; Pelle, Henri; Sichler, Bertrand; Voisset, Michel; Watremez, Pierre; Vaslet, N; Jean Baptiste, P. |
| Tipo: Text |
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| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00070/18104/15652.pdf |
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| Auzende, Jean Marie; Urabe, T; Ruellan, E; Chabroux, D; Charlou, Jean-luc; Gena, K; Gamo, T; Henry, K; Matsubayashi, O; Matsumoto, T; Naka, J; Nagaya, Y; Okamura, K. |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00070/18099/15647.pdf |
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| Charlou, Jean-luc; Charlot, M. |
| Les premiers résultats concernant le comportement de composés organo-métalliques (alkyls plomb : plo:nb tétra-éthyl et méthyl) sont résumés dans ce rapport. La technique d'analyse du plomb organique dnns les sédiments (par minéralisation ou extraction au méthanol) a été mise au point. Les premières observations sont seulement basées sur les analyses de plomb minéral. La dégradation du PTE dans l'eau de mer et la phase sédimentaire est beaucoup plus rapide que celle du Ptm; lES RAYONS uv ONT UNE ACTION IMPORTANTE SUR CETTE D2GRADATION; Les PTE et PTM, de par leur densité élevée (+ de 1,5), leur insolubilité dans l'eau, diffusent très faiblement dans l'eau. Ils se dégradent sur le fond marin, où la densité du sédiment déposé jouera un rôle important dans la... |
| Tipo: Text |
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| Ano: 1977 |
URL: http://archimer.ifremer.fr/doc/00132/24316/22314.pdf |
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| Mousis, Olivier; Chassefiere, Eric; Holm, Nils G.; Bouquet, Alexis; Waite, Jack Hunter; Geppert, Wolf Dietrich; Picaud, Sylvain; Aikawa, Yuri; Ali-dib, Mohamad; Charlou, Jean-luc; Rousselot, Philippe. |
| We review the reservoirs of methane clathrates that may exist in the different bodies of the Solar System. Methane was formed in the interstellar medium prior to having been embedded in the protosolar nebula gas phase. This molecule was subsequently trapped in clathrates that formed from crystalline water ice during the cooling of the disk and incorporated in this form into the building blocks of comets, icy bodies, and giant planets. Methane clathrates may play an important role in the evolution of planetary atmospheres. On Earth, the production of methane in clathrates is essentially biological, and these compounds are mostly found in permafrost regions or in the sediments of continental shelves. On Mars, methane would more likely derive from... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00266/37718/41116.pdf |
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| Registros recuperados: 55 | |
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