RANGIN , Claude

New multi-channel seismic data were acquired in the northern part of the Bay of Bengal and at the northernmost termination of the 90°E Indian Ridge offshore Bangladesh. This survey was coupled with a seismic refraction experiment indicating this offshore basin is here floored by a thinned (15 km thick) continental crust, injected by Mesozoic...

The northern Bay of Bengal velocity-depth profiles do not follow the velocity-depth curve for the North Atlantic volcanic margins, and only partially the Kerguelen plume velocity-depth curves. Compared with the South China Sea northern margin proxy, we still suggest that the Bay of Bengal crust is thinned continental crust intruded by...

Plate motion along the Indo-Burmese Arc (IBA), strain accommodation in the Indo-Burmese wedge, status of active convergence and seismic vulnerability in the outer wedge, is a matter of concern due to the large population density in northeast India, Bangladesh, and Myanmar. In the present study, we have constrained the India-Sunda plate motion...

International audience

The ∼1200 km long north-south oriented Sagaing fault (plate boundary fault between the Burma and Sunda plates), entirely located in Myanmar, passes through some major cities, and has witnessed several major earthquakes since prehistoric time, including the recent Mw 6.8 Thabeikkyin earthquake in 2012. The Sagaing fault accommodates ∼50–55% of...

Since the early Cretaceous, the Bay of Bengal was formed during rifting between India and Antarctica and then by subsequent seafloor spreading. The nature of the crust underlying the Bay of Bengal is oceanic south of 15°N, but remains unknown (thinned continental crust, serpentinized mantle or oceanic crust) north of this limit. In order to...

We surveyed the junction between the central and southern Philippine Trench and the Sangihe Trench near 6øN using swath bathymetry, gravity, and magnetics. These data, along with seismicity, allow us to discuss the genetic relations between these trenches and the forces acting on converging plates. Our final model favors the northern extension...

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...

A swath mapping, gravity and single channel seismic survey was carried out in the northern Molucca Sea with R.V. L'Atalante. Preliminary interpretation of these data reveals the presence of an almost complete Sangihe arc and forearc. The Miangas-Pujada-Talaud ridge in the central part of the Molucca Sea appears to be a backstop within the...

Earthquake scarps associated with recent historical events have been found on the floor of the Sea of Marmara, along the North Anatolian Fault (NAF). The MARMARASCARPS cruise using an unmanned submersible (ROV) provides direct observations to study the fine-scale morphology and geology of those scarps, their distribution, and geometry. The...