VT 95 / DEFLO-HYDRO-A
| Type | Oceanographic cruise |
|---|---|
| Ship | Marion Dufresne |
| Ship owner | TAAF |
| Dates | 03/01/2008 - 07/02/2008 |
| Chief scientist(s) | ROYER Jean-Yves  |
GEO-OCEAN - UMR 6538 Univ. Brest, CNRS, Ifremer, Univ. Bretagne Sud Place Nicolas Copernic 29280 Plouzané |
|
| DOI | 10.17600/8200090 |
| Objective | DEFLO-HYDRO (observation of DEFormation of the ocean Lithosphere using HYDROphones) is a continuous hydroacoustic project lasting more than one year (12-18 months) to observe seismic activity in the Indian Ocean. For this project, 3 autonomous hydrophones were submerged in the SOFAR channel for 14 months between the Reunion, Kerguelen and Amsterdam islands. They were deployed during the MD157 cruise (Oct 2006). They were retrieved during two missions in January 2008 (MD165-VT95) and April 2008 (OP2008/1). The proposed system was configured to ensure continuous acoustic monitoring of 3 ridges with different opening rates (16 to 70 mm/year) and of the intra-plate deformation in the south of the Central Indian basin. The approach is particularly effective in detecting and locating low magnitude seismicity (>2.5) which is not caught by seismological arrays on land and in distinguishing events of tectonic or magmatic events. The objectives were to characterize the functioning over time and space of 3 ultra-slow, slow and intermediate ridges, to specify the distribution over time and space of intra-plate deformations and to check the presence of low magnitude foreshocks before major earthquakes on active subsea faults. This observatory will also be used to detect the acoustic activity of marine mammals, and particularly large whales. It falls under the DEFLO-HYDRO project. |
