SISMANTILLES 1
Type | Oceanographic cruise |
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Set | This cruise is part of the set SISMANTILLES |
Ship | Le Nadir |
Ship owner | Ifremer |
Dates | 27/11/2001 - 22/12/2001 |
Chief scientist(s) | HIRN Alfred |
INSTITUT DE PHYSIQUE DU GLOBE DE PARIS - UMR 7154, UMS 3454 1 rue Jussieu 75005 Paris +33 (0)1 83 95 74 00 |
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DOI | 10.17600/1080060 |
Objective | The SISMANTILLES cruise was part of a coordinated research project on the structure and the seismic and volcanic activity of an active subduction zone found in the Lesser Antilles Island arc, namely where Martinique and Guadeloupe are located. The overall objective was to update our understanding of the interaction of converging plates and their internal deformation in this zone. This is one of the most poorly known subduction zones, due to, in particular, its current moderate level of seismicity and its very short historical record. A significant international research effort was already in progress on the seismogenic zone of the large subduction zones in the periphery of the Pacific Ocean. Here, we wished to highlight another typical example, that of small-scale island arcs. To study the deep structure of this active margin, we adapted multichannel seismic reflection (MCS) to greater depths by optimizing powerful "single-bubble" sources; 2,500 km of profiles were made. The seismic refraction method was implemented from the same source recorded from land sensors and 39 ocean-bottom sensors (OBS). Complementary methods were used, such as tomography based on the earthquakes recorded using by OBS sensors on the seafloor and sensors on land. Observation of local earthquakes was to be radically improved by using a temporary network of sensors deployed in the (OBS sensors) and increased density on land. These data were to give an instant image of the deformation and constraint regime and focal mechanism distribution. We thus aimed to explore the relationship between the instantaneous deformation and the final deformation whose marks are left in the structure. The spatial distribution was to be discussed in terms of structural changes and evaluation of natural hazards. |