|
|
|
|
|
| Graindorge, D; Klingelhoefer, Frauke; Sibuet, Jean-claude; Mcneill, L; Henstock, T; Dean, S; Gutscher, M; Dessa, J; Permana, H; Singh, S; Leau, H; White, N; Carton, H; Malod, Jacques-andre; Rangin, C; Aryawan, K; Chaubey, A; Chauhan, A; Galih, D; Greenroyd, C; Laesanpura, A; Prihantono, J; Royle, G; Shankar, U. |
| We present results from multibeam bathymetric data acquired during 2005 and 2006, in the region of maximum slip of the 26 Dec. 2004 earthquake (Mw 9.2). These data provide high-resolution images of seafloor morphology of the entire NW Sumatra forearc from the Sunda trench to the submarine volcanic arc just north of Sumatra. A slope gradient analysis of the combined dataset accurately highlights those portions of the seafloor shaped by active tectonic, depositional and/or erosional processes. The greatest slope gradients are located in the frontal 30 km of the forearc, at the toe of the accretionary wedge. This suggests that long-term deformation rates are highest here and that probably only minor amounts of slip are accommodated by other thrust faults... |
| Tipo: Text |
Palavras-chave: Sumatra; Tectonic; Seafloor morphology; Accretionary wedge; Subduction. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5166.pdf |
| |
|
|
| Westbrook, G; Chand, S; Rossi, G; Long, C; Bunz, S; Camerlenghi, A; Carcione, J; Dean, S; Foucher, Jean-paul; Flueh, E; Gei, D; Haacke, R; Madrussani, G; Mienert, Jurgen; Minshull, T; Nouze, Herve; Peacock, S; Reston, T; Vanneste, M; Zillmer, M. |
| High-resolution seismic experiments, employing arrays of closely spaced, four-component ocean-bottom seismic recorders, were conducted at a site off western Svalbard and a site on the northern margin of the Storegga slide, off Norway to investigate how well seismic data can be used to determine the concentration of methane hydrate beneath the seabed. Data from P-waves and from S-waves generated by P-S conversion on reflection were inverted for P- and S-wave velocity (V-p and V-s), using 3D travel-time tomography, 2D ray-tracing inversion and 1D waveform inversion. At the NW Svalbard site, positive V-p anomalies above a sea-bottom-simulating reflector (BSR) indicate the presence of gas hydrate. A zone containing free gas up to 150-m thick, lying immediately... |
| Tipo: Text |
Palavras-chave: Continental margin; Hydrate concentration; Seismic velocity; S wave; P wave. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6122.pdf |
| |
|
|
|
