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Urgeles, Roger; Cattaneo, Antonio; Puig, Pere; Liquete, Camino; De Mol, Ben; Amblas, David; Sultan, Nabil; Trincardi, Fabio. |
Most Mediterranean prodeltas show undulated sediment features on the foresets of their Holocene wedges. These features have been described all along the Mediterranean for the last 30 years and interpreted as either soft sediment deformation and incipient landsliding, and more recently, as sediment transport structures. We perform a review and detailed analysis of these undulated sediment features using ultrahigh-resolution seismic and bathymetric data as well as geotechnical information and hydrodynamic time series and hydrographic transects. In this study we show that the characteristics of the sediment undulations (configuration of the reflections down section and between adjacent undulations and overall morphologic characteristics) are incompatible with... |
Tipo: Text |
Palavras-chave: Undulated sediments; Prodeltas; Slope failure; Sediment waves; Hyperpycnal flows; Internal waves. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15388/12841.pdf |
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Sultan, Nabil; Cattaneo, Antonio; Sibuet, Jean-claude; Schneider, Jean-luc. |
The swath bathymetric data acquired during the "Sumatra Aftershocks" cruise from the Sunda trench in the Indian Ocean to the north of the Sumatra Island imaged several scars and deposits. In situ pore pressure measurements using the Ifremer piezometer and coring demonstrate that high excess pore pressure and sediment deformation was generated by a recent event in the scar of the slope failure zone identified by J.T. Henstock and co-authors. This excess pore pressure is localized in the upper sedimentary layers and is not related to an interplate subduction process. Numerical simulations of the hydrological system that take into account the hydro-mechanical properties of the upper sediment layer show that the excess pore pressure and sediment deformations... |
Tipo: Text |
Palavras-chave: Tsunami; Sumatra; Slope failure; Pore pressure; Earthquake. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6740.pdf |
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Sultan, Nabil; Cochonat, Pierre; Foucher, Jean-paul; Mienert, J. |
We present a theoretical study of the thermodynamic chemical equilibrium of gas hydrate in soil by taking into account the influence of temperature, pressure, pore water chemistry, and the mean pore size distribution. The model uses a new formulation based on the enthalpy form of the law of conservation of energy. The developed model shows that due to a temperature and pressure increase, hydrates may dissociate at the top of the hydrate occurrence zone to ensure a chemical equilibrium with the surrounding bulk water. This original result confirms what has been already shown through experiments. The second part of the paper presents an application of the model through a back-analysis of the giant Storegga Slide on the Norwegian margin. Two of the most... |
Tipo: Text |
Palavras-chave: Storegga; Slope failure; GLE; Finite difference; Methane hydrate. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-699.pdf |
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Hillman, Jess I. T.; Klaucke, Ingo; Bialas, Joerg; Feldman, Howard; Drexler, Tina; Awwiller, David; Atgin, Orhan; Cifci, Gunay; Badhani, Shray. |
A large geophysical dataset, including bathymetry, and 2D and 3D P-cable seismic data, revealed evidence of numerous gas flares near the S2 Canyon in the Danube Fan, northwestern Black Sea. This dataset allows us to investigate potential relationships between gas migration pathways, gas vents observed at the seafloor and submarine slope failures. Vertical gas migration structures as revealed in the seismics appear to be concentrated near submarine slope failure structures. Where these seismically defined features extend upwards to the seafloor, they correlate with the location of gas flares. However, not all these structures reach the seafloor, in some cases because they are capped by overlying sediments. A strong correlation is inferred between gas... |
Tipo: Text |
Palavras-chave: Gas migration; Chimneys; Gas hydrate; Danube Fan; Slope failure; Black Sea. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00439/55013/57803.pdf |
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