Morphodynamique d'une dune sous-marine du détroit du Pas de Calais

Déborah Idier (1, 2) , Axel Ehrhold (3) , Thierry Garlan (3)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
2 IMFT - Institut de mécanique des fluides de Toulouse
3 EPSHOM - Établissement principal du Service hydrographique et océanographique de la Marine

Morphodynamics of an undersea sandwave of the Dover Straits. This paper investigates the dynamics of sandwaves in relationship with tidal currents and weather conditions. The studied sandwaves are located in the Dover Straits and are covered by megaripples. These megaripples have migration speeds of 1 mh−1 and slopes of 34◦, suggesting the potential for avalanches to occur along the flanks of the sandwave. Tidal cycles without reversing currents were observed during stormy weather.Wind-induced currents lead to a unidirectionalmigration of megaripples and sandwaves.Well-defined areas without megaripples were observed and correlated with an increase in sandwave height.We propose interpretations for understanding sandwave saturation and migration

Mots clés: dune; mégarides; courants; multi-faisceau; dynamique; tempêtes; avalanches

Domaines: Océanographie

Déborah Idier, Axel Ehrhold, Thierry Garlan. Morphodynamique d'une dune sous-marine du détroit du Pas de Calais. Comptes Rendus Géoscience, 2002, 334 (15), pp.1079-1085. ⟨10.1016/S1631-0713(02)01852-7⟩. ⟨hal-00557295⟩