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| Zitter, T; Henry, P; Aloisi, G; Delaygue, G; Cagatay, M; De Lepinay, B; Al Samir, M; Fornacciari, F; Tesmer, M; Pekdeger, A; Wallmann, K; Lericolais, Gilles. |
| The main Marmara Fault exhibits numerous sites of fluid venting, observed during previous cruises and in particular with R.O.V. VICTOR during the MARMARASCARPS cruise (2002). Long CALYPSO cores were recovered near active vents and at reference sites during the MARMARA-VT cruise (2004), together with echosounder sub-bottom profiles (frequency of 3.5kHz). We compiled R.O.V. video observations from MARMARASCARPS cruise and show that all known seeps occur in relationship with strike-slip faults, providing pathways for fluid migration. Among the main active sites, a distinction is made between gas seeps and water seeps. At gas seeps, bubble emissions at the seafloor or disturbed echofacies on sounder profiles demonstrate the presence of free methane gas at a... |
| Tipo: Text |
Palavras-chave: High permeability pathways; Fault scarp; Seafloor observations; Cold seeps; Sea of Marmara. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4065.pdf |
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| Geli, Louis; Henry, P; Zitter, T; Dupre, Stephanie; Tryon, M; Cagatay, M; De Lepinay, B; Le Pichon, X; Sengor, A; Gorur, N; Natalin, B; Ucarkus, G; Oezeren, S; Volker, D; Gasperini, L; Burnard, P; Bourlange, S. |
| The submerged section of the North Anatolian fault within the Marmara Sea was investigated using acoustic techniques and submersible dives. Most gas emissions in the water column were found near the surface expression of known active faults. Gas emissions are unevenly distributed. The linear fault segment crossing the Central High and forming a seismic gap - as it has not ruptured since 1766, based on historical seismicity [Ambraseys, N.N., and Jackson, J.A., (2000), Seismicity of the Sea of Marmara (Turkey) since 1500, Geophys. J. Int., 141, (3), F1-F6. (doi:10.1046/j.1365-246x.2000.00137.x: Ambraseys, N., (2002), The seismic activity of the Marmara Region over the last 2000 years, Bull. Seism. Soc. Am., 92, 1-18; Parson, T., (2004), Recalculated... |
| Tipo: Text |
Palavras-chave: North Anatolian Fault; Marmara Sea; Gas emission; Fluids; Seismicity. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4681.pdf |
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| De Garidel-thoron, T; Beaufort, L; Bassinot, F; Henry, P. |
| Past atmospheric methane-concentration oscillations recorded in polar ice cores vary together with rapid global climatic changes during the last glacial episode. In the "clathrate gun hypothesis," massive releases of deep-sea methane from marine gas-hydrate dissociation led to these well known, global, abrupt warmings in the past. If evidence for such releases in the water column exists, however, the mechanism and eventual transfer to the atmosphere has not yet been documented clearly. Here we describe a high-resolution marine-sediment record of stable carbon isotopic changes from the Papua Gulf, off Papua New Guinea, which exhibits two extremely depleted excursions (down to -9parts per thousand) at approximate to39,000 and approximate to55,000 years.... |
| Tipo: Text |
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| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00226/33734/32378.pdf |
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| Martin, V; Henry, P; Nouze, Herve; Noble, M; Ashi, J; Pascal, G. |
| In 2000, a 3D MCS survey was carried out on the Eastern Nankai Trough. A strong and widespread bottom-simulating reflector (BSR) was observed and mapped after a preserved amplitude 3D prestack migration of the seismic data. We use this BSR to calculate a heat flow map over the 3D survey area. This map presents some high and low heat flow areas, that cannot be correlated to known active wedge faults and previously observed fluid venting sites. Since the heat flow anomalies are not correlated to known major faults or fluid venting sites, large fluid circulation is not likely to explain the varying BSR-derived heat flow distribution. In order to explain this heat flow distribution quantitatively, we calculate the rates of erosion and sedimentation that are... |
| Tipo: Text |
Palavras-chave: Eastern Nankai margin; Surface processes; Heat flow; Bottom simulating reflector. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-509.pdf |
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| Nouze, Herve; Henry, P; Noble, M; Martin, V; Pascal, G. |
| Previous studies have revealed the presence of a widespread Bottom Simulating Reflector (BSR) on the eastern Nankai slope, as well as the occurrence of enigmatic high amplitude reflections that extend well above the BSR. New high-resolution 2-D seismic data were collected on the eastern Nankai slope, during the French-Japanese SFJ cruise in year 2000 and AVA analyses of the enigmatic reflectors are conducted. At the studied location, these analyses suggest that high amplitude anomalies above the BSR delineate the top of gas hydrate rich sediments. Several tens % of the sediment porosity would be filled with gas hydrates between the BSR and a sharp boundary 30 to 60 m above. To account for these observations, we propose that an invasion by free gas of the... |
| Tipo: Text |
Palavras-chave: Zone; Model; Ridge; Methane gas; Marine sediments. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-510.pdf |
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