PROSECAN 1
| Type | Oceanographic cruise |
|---|---|
| Ship | Thalia |
| Ship owner | Ifremer |
| Dates | 06/08/2003 - 19/08/2003 |
| Chief scientist(s) | CIRAC Pierre |
ENVIRONNEMENTS ET PALÉOENVIRONEMENTS OCÉANIQUES ET CONTINENTAUX (EPOC) - TALENCE UMR CNRS 5805 EPOC - OASU - Université de Bordeaux Bâtiment A12 351 Cours de la Libération 33405 TALENCE CEDEX +33 (0)5 40 00 36 15 |
|
| DOI | 10.17600/3070190 |
| Objective | The PROSECAN cruise aimed to study sedimentary processes Cap Breton canyon and its northern edge (Landes shelf) by making a) a sidescan sonar mosaic at the top of the Cap Breton canyon; b) bathymetric survey of the large valley adjacent to the canyon, running along the Landes shelf from North to South using the EM1000 multibeam echosounder; c) supplementary seismic lines in the valley area as well as on the thalweg canyon terraces; and d) 29 Kullenberg core samples along a series of transects cutting across the canyon's thalweg. The imaging mosaic at the top of the canyon confirmed more clearly and accurately than with previous (Itsas 6) observations, the presence of sandy ripples probably due to instability phenomena, sand slides from the underwater beach. The multibeam echosounder profiles made in the south-eastern part of the Landes shelf completed the bathymetry of the adjacent valley begun in previous missions. On this occasion we observed pockmark and sediment wave type morphologies on the western slope of the zone. Single channel sparker lines showed the continuity of reflections from one edge to another of the adjacent valley. Thus, the Western margin is not a large sedimentary levee, as had been thought. VHR seismics also accurately showed the structures inherent to sediment waves on the western slope of the area. Initial observations of Kullenberg core samples confirmed that the coarse sediment (from sandy to gravelly) is limited to the bottom of the thalweg. Currently, it only seems to come from the top of the canyon. |
