Canyon of Capbreton: new morphostructural and morphosedimentary approaches. First results of the ITSAS cruise

A recent cruise of the Suroit using new technologies for acquisition and pr ocessing of acoustic data (very high-resolution seismic and swath mapping) associated to an accurate satellite positioning, allowed producing a new ba thymetric map of the upper part of the canyon. It shows the meandering shap e of the canyon and superposed polyphase terrace. Such a morphology is due to activity of gravity flows that occurred as soon as the Upper Eocene. Ver y high-resolution seismic data allowed to confirm the influence of old tect onic structures on the location and the general shape of the canyon and to show that neotectonics that affects Plio-Quaternary deposits corresponds to recurrent activity of old tectonic structures. (C) 2001 Academie des scien ces / Editions scientifiques et medicales Elsevier SAS.