Abstract : Richards [1980] conjectured that megaripples of the continental shelf are due to a seabed instability in the presence of seabed ripples. Towards a better understanding of this megaripple formation process, we use a morphodynamical numerical model to investigate the bed roughness influence on the bed load–induced linear stability of a sandy bed. We find that the linearly most amplified mode shifts from a dune mode (grain roughness) towards a megaripple mode (large bed roughness). Then, we discuss how megaripples could be generated over a flat bed and over dunes.
https://hal-brgm.archives-ouvertes.fr/hal-00557292
Contributeur : Déborah Idier <>
Soumis le : mardi 18 janvier 2011 - 18:59:59 Dernière modification le : jeudi 4 mars 2021 - 13:50:03
Déborah Idier, Dominique Astruc, Suzanne J.M.H. Hulscher. Influence of bed roughness on dune and megaripple generation. Geophysical Research Letters, American Geophysical Union, 2004, 31, pp.L13214. ⟨10.1029/2004GL019969⟩. ⟨hal-00557292⟩