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| Registros recuperados: 28 | |
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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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| Ondreas, Helene; Olu, Karine; Dupre, Stephanie; Scalabrin, Carla; Alix, Anne-sophie; Garrocq, Clément; Ruffine, Livio. |
| The Sea of Marmara hosts part of the North Anatolian Fault as an active submarine strike-slip fault. This area has suffered numerous earthquakes and presents a major seismic risk. Although the Sea of Marmara has been studied for many years, the link between geological morphostructures, the nature of fluids and biological communities is still rarely described. During the Marsite cruise (November 2014), dives with Remotely Operated Vehicle (ROV) VICTOR 6000 focused on detailed seafloor explorations of four different areas: the Central and Western highs and the Tekirdağ and Çinarcik basins. Based on 130 h of in situ videos, high-resolution seafloor mapping of seeps was conducted, emphasizing their significant geological and biological diversity from one... |
| Tipo: Text |
Palavras-chave: Sea of Marmara; Cold seeps; Fluids; Seismogenic faults; Chemosynthetic fauna; Methane. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00624/73623/73040.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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| 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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| Sen, Arunima; Ondreas, Helene; Gaillot, Arnaud; Marcon, Yann; Augustin, Jean-marie; Olu, Karine. |
| Deep-sea ecosystems have attracted considerable commercial interest in recent years because of their potential to sustain a diverse range of mankind's industrial needs. If these systems are to be preserved or exploited in a sustainable manner, mapping habitats and species distributions is critical. As biodiversity at cold-seeps or other deep-sea ecosystems is driven by habitat heterogeneity, imagery is the obvious choice for characterizing these systems and has indeed proven extremely valuable towards mapping biogenic habitats formed by dense aggregations of large sized species, such as coral reefs, tubeworm bushes or bivalve beds. However, the acquisition of detailed images with resolution sufficient for reliable identification is extremely time... |
| Tipo: Text |
Palavras-chave: Mapping; Cold seeps; Multibeam; Bathymetry; Backscatter; Biogenic habitats. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00312/42286/41612.pdf |
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| Ondreas, Helene; Ruellan, Etienne; Auzende, Jean-marie; Bendel, V; De Alteriis, G; Gracia Mont, Eulalia; Tanahashi, M. |
| During the STARMER programme the submersibles Nautile and Shinkai-6500 carried out 14 dives on the NS segment of the North Fiji Basin Ridge (Station 14 at 18-degrees-50 S). From structural point of view, two types of morphology appear: in the northern part, the axis is not tectonically well expressed hut the hydrothermal activity is important. in the southern part, a graben structure 150 m wide exists, with both a.fossil and a present-day hydrothermal activity. The station 14 shows a morphostructural variability of the spreading axis which can be related to the different stages of the volcanic and tectonic cycles. Another station explored at 19-degrees-S, a few kilometres to the south, confirms the fact that different stages of tectonic and magmatic... |
| Tipo: Text |
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| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00184/29476/27855.pdf |
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| Ondreas, Helene; Aslanian, Daniel; Geli, Louis; Olivet, Jean-louis; Briais, Anne. |
| The spreading rate at the Pacific-Antarctic Ridge (PAR) increases rapidly from 54 mm/yr near Pitman Fracture Zone (FZ) up to 76 mm/yr near Udintsev FZ, resulting in three domains of axial morphology: an axial valley south of Pitman FZ, an axial high north of Saint Exupery FZ, and in between, the transitional domain extends over 650 km. It comprises sections of ridge with an axial valley or an axial high and generally displays a very low cross-sectional relief. It is also characterized by two propagating rifts. Two domains of different seafloor roughness appear south of Udintsev FZ: east of 157 degreesW these two domains are separated by a 1000-km V-shaped boundary. West of 157 degreesW, the boundary approximately coincides with Chron 3a or Chron 4. The... |
| Tipo: Text |
Palavras-chave: Spreading; Segmentation; Geomorphology; Seafloor; Ridge. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2001/publication-438.pdf |
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| Fouquet, Yves; Barriga, F; Charlou, Jean-luc; Elderfield, H; German, C.r; Ondreas, Helene; Parson, L; Radford-knoery, Joel; Relvas, J; Ribeiro, A; Schultz, A; Apprioual, R; Cambon, P; Costa, I; Donval, Jean-pierre; Douville, E; Landure, Jy; Normand, A; Pelle, H; Ponsevera, E. |
| Tipo: Text |
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| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00070/18133/15681.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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| 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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| Briais, Anne; Ondreas, Helene; Klingelhoefer, Frauke; Dosso, Laure; Hamelin, Cedric; Guillou, Herve. |
| Non-hot spot, intraplate volcanism is a common feature near the East Pacific Rise or Pacific-Antarctic ridge. Volcanic ridges and seamount chains, tens to hundreds of kilometers long, are asymmetrically distributed about the ridge axis, with most volcanic features occurring on the Pacific plate. Their origins remain controversial. We have analyzed off-axis volcanic ridges near the Pacific-Antarctic ridge from bathymetry, backscatter, gravity, and geochemistry data of the Pacantarctic 2 cruise. K/Ar dating of samples dredged on these structures reveals a contrast of up to 3 Ma between the volcanoes and the underlying crust. The volcanic activity, as suggested by the strong backscatter in sonar images, appears to be limited to areas of seafloor younger than... |
| Tipo: Text |
Palavras-chave: Mid ocean ridges; Off axis volcanism; Mantle convection; Plate kinematics; Transform fault. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11106/7968.pdf |
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| Ondreas, Helene; Cannat, M.; Fouquet, Yves; Normand, Alain; Sarradin, Pierre-marie; Sarrazin, Jozee. |
| We present new high-resolution bathymetry and backscatter data acquired in 2006 with the ROV Victor 6000 over the Lucky Strike hydrothermal field, Mid-Atlantic Ridge. As long-term monitoring of the Lucky Strike area (MoMAR project) is being implemented, these new high-resolution data offer an unprecedented view of the distribution of hydrothermal edifices, eruptive facies, and small-scale tectonic features in the Lucky Strike vent field. We show that vents located in the NW and NE correspond with wide expanses of lumpy seafloor which we interpret as primarily made of broken chimneys and sulfide edifices. They are found above scarps with relief > 50 m or on associated mass wasting deposits. By contrast, the SE and SW vents correspond with small expanses... |
| Tipo: Text |
Palavras-chave: Hydrothermalism; Lava lake; Lucky Strike; Mid Atlantic Ridge. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6161.pdf |
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| Auzende, Jean-marie; Tanahashi, M; Bendel, V; Fujikura, K; Geistdoerfer, P; Gracia Mont, Eulalia; Joshima, M; Kisimoto, K; Mitsuzawa, K; Murai, M; Nojiri, Y; Ondreas, Helene; Pratt, C; Ruellan, Etienne. |
| The aim of the YOKOSUKA 91 cruise (October 1991) of the Japanese submersible Shinkai 6500 was to come back on two hydrothermal sites of the axis of the North Fiji Basin ridge which had already been explored by the submersible Nautile in 1989. This cruise gave us the opportunity to show that the hydrothermal manifestations vary a lot in terms of geology, geochemistry or biology during a very short time. A new site which is located in a deep graben of the N 160 ridge axis showed only activity along a fault system marked by sulphide deposits. |
| Tipo: Text |
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| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00184/29486/27854.pdf |
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| Registros recuperados: 28 | |
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