Contributions respectives des courants et de la houle dans la mobilité sédimentaire dʹune plate-forme interne estuarienne. Exemple : le seuil interinsulaire, au large du pertuis dʹAntioche, France

This paper investigates the relative influence of waves, wind-induced current and tidal current on the sediment mobility of a macro-tidal environment belonging to the inner shelf seaward of the ‘pertuis Charentais’ (France). This study, mainly based on three-week hydrodynamic in-situ measurements, shows that, for a water depth of 23 m, the swell (rather than wind waves) orbital velocity is large enough to initiate the motion of medium sands that are then transported by currents. Estimations show that medium sand of 0.2 mm is transported during 92% of the measurements, whereas coarse sand and gravel move sporadically, during storm, synchronously with spring tides. Further more, bedload fluxes appear strongly larger when waves are taken into account (370 times larger for 0.2-mm sands). To cite this article: D. Idier et al., C. R. Geoscience 338 (2006).