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| Biari, Youssef; Klingelhoefer, Frauke; Sahabi, Mohamed; Aslanian, Daniel; Schnurle, Philippe; Berglar, K.; Moulin, Maryline; Mehdi, K.; Graindorge, D.; Evain, Mikael; Benabdellouahed, Massinissa; Reichert, C.. |
| The structure of the Moroccan and Nova Scotia conjugate rifted margins is of key importance for understanding the Mesozoic break-up and evolution of the northern central Atlantic Ocean basin. Seven combined multichannel reflection (MCS) and wide-angle seismic (OBS) data profiles were acquired along the Atlantic Moroccan margin between the latitudes of 31.5° and 33° N during the MIRROR seismic survey in 2011, in order to image the transition from continental to oceanic crust, to study the variation in crustal structure and to characterize the crust under the West African Coast Magnetic Anomaly (WACMA). The data were modeled using a forward modeling approach. The final models image crustal thinning from 36 km thickness below the continent to approximately 8... |
| Tipo: Text |
Palavras-chave: Moroccan continental margin; Wide-angle seismic modeling; Deep crustal structure; Ocean continent transition. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38401/36726.pdf |
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| Klingelhoefer, Frauke; Gutscher, M. -a.; Ladage, S.; Dessa, J. -x.; Graindorge, D.; Franke, D.; Andre, Camille; Permana, H.; Yudistira, T.; Chauhan, A.. |
| The 26 December 2004 Sumatra earthquake (M-w = 9.1) initiated around 30 km depth and ruptured 1300 km of the Indo-Australian-Sunda plate boundary. During the Sumatra-OBS (ocean bottom seismometer) survey, a wide-angle seismic profile was acquired across the epicentral region. A seismic velocity model was obtained from combined travel time tomography and forward modeling. Together with reflection seismic data from the SeaCause II cruise, the deep structure of the source region of the great earthquake is revealed. Four to five kilometers of sediments overlie the oceanic crust at the trench, and the subducting slab can be imaged down to a depth of 35 km. We find a crystalline backstop 120 km from the trench axis, below the fore-arc basin. A high-velocity zone... |
| Tipo: Text |
Palavras-chave: Middle america trench; Fore arc basin; Bottom seismographic observation; Subduction zone; Crustal structure; Accretionary prism; Mantle serpentinization; Aftershock distribution; Megathrust earthquakes; Velocity structure. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00000/11155/7737.pdf |
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| Chauhan, Ajay P. S.; Singh, Satish C.; Hananto, Nugroho D.; Carton, Helene; Klingelhoefer, Frauke; Dessa, J. -x.; Permana, H.; White, N. J.; Graindorge, D.. |
| Forearc tectonics at accretionary convergent margins has variously been studied using analogue and numerical modelling techniques. Numerous geophysical investigations have targeted the subsurface structure of active forearc settings at convergent margins. However, several critical details of the structure, mode of tectonic evolution and the role forearcs play in the subduction seismic cycle remain to be further understood, especially for large accretionary margins. In this study, we present a high-resolution deep seismic reflection image of the northern Sumatran subduction forearc, near the 2004 December 26 Sumatra earthquake epicentral region. The profile clearly demarcates the backthrust branches at the seaward edge of the Aceh forearc basin, along which... |
| Tipo: Text |
Palavras-chave: Forearc backthrusting; Seismic reflection image; Seismic tomography; Subduction zone processes. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00000/11120/7720.pdf |
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| Loncke, L.; Maillard, A.; Basile, C.; Roest, Walter; Bayon, Germain; Gaullier, V.; Pattier, France; Mercier De Lépinay, Marion; Grall, Celine; Droz, L.; Marsset, Tania; Giresse, P.; Caprais, Jean-claude; Cathalot, Cecile; Graindorge, D.; Heuret, A.; Lebrun, J. F.; Bermell, Sylvain; Marcaillou, B.; Sotin, C.; Hebert, B.; Patriat, Martin; Bassetti, M. A.; Tallobre, Cedric; Buscail, R.; Durrieu De Madron, X.; Bourrin, F.. |
| he IGUANES cruise took place in May 2013 on the R/V L'Atalante along the Demerara passive transform margin off French Guiana and Surinam. Seismic, multibeam and chirp acquisitions were made. Piston cores were collected for pore geochemistry and sedimentology. A mooring was deployed on the sea-bottom for 10 months (temperature, salinity, turbidity and current measurements). This new dataset highlights the lateral variability of the 350 km-long Guiana–Surinam transform margin due to the presence of a releasing bend between two transform segments. The adjacent Demerara Plateau is affected by a 350 km-long giant slide complex. This complex initiated in Cretaceous times and was regularly reactivated until recent times. Since the Miocene, contourite processes... |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00428/53942/55285.pdf |
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| Laurencin, Muriel; Marcaillou, B.; Graindorge, D.; Klingelhoefer, Frauke; Lallemand, S.; Laigle, M.; Lebrun, J. -f.. |
| The influence of the highly oblique plate convergence at the northern Lesser Antilles onto the margin strain partitioning and deformation pattern, although frequently invoked, has never been clearly imaged. The Anegada Passage is a set of basins and deep valleys, regularly related to the southern boundary of the Puerto-Rico-Virgin-Islands (PRVI) microplate. Despite the publications of various tectonic models mostly based on bathymetric data, the tectonic origin and deformation of this Passage remains unconstrained in the absence of deep structure imaging. During cruises Antithesis 1 and 3 (2013 - 2016), we recorded the first deep multichannel seismic images and new multibeam data in the northern Lesser Antilles margin segment in order to shed a new light... |
| Tipo: Text |
Palavras-chave: Oblique subduction zone; Strain partitioning; Anegada Passage; Lesser Antilles margin; Multichannel seismic reflection. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00386/49710/50236.pdf |
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