Origin of rippled scour depressions associated with cohesive sediments in a shoreface setting (eastern Bay of Seine, France)     

Sébastien Garnaud  Patrick Lesueur  Thierry Garlan 《Geo-Marine Letters》2005,25(1):34-42

Side-scan sonar investigations in the eastern part of the macrotidal Bay of Seine have revealed the presence of numerous rippled scour depressions (RSDs) at water depths of 5–9 m. The sediments in these depressions consist essentially of coarse-grained shell hash derived from underlying Holocene sediments dated at roughly 6,500 years BP, and arranged in large wave-generated ripples. The shallow marine area where these features occur consists of a wave-generated ravinement surface produced during the marine flooding of the late Holocene transgression. It can be shown that, during the last 20 years at least, erosion of the muddy sand and sandy seabed has exposed underlying relict sediments. These consist of stiff clays, silts and a layer of shell debris which, when exposed, cover the bottom of large scour depressions which appear to be in equilibrium with the local hydrodynamic regime. Morphological and hydrodynamic data suggest that the RSDs are generated by strong cross-shore bottom currents flowing parallel to the features in the direction of the prevailing waves, and probably associated with storm-induced downwelling events.  相似文献   

Impact of interactive vegetation phenology on the Canadian RCM simulated climate over North America     

Garnaud  Camille  Sushama  Laxmi  Verseghy  Diana 《Climate Dynamics》2015,45(5-6):1471-1492

Climate Dynamics - Biosphere–atmosphere interactions play a very important role in modulating regional climate. To capture these bi-directional interactions, a dynamic vegetation model, the...  相似文献   

Caractérisation des variations lithologiques saisonnières des sédiments de la baie de Seine orientale ; impact des crues de la Seine (France)Characterisation of seasonal lithological variations of the superficial sediment in the eastern part of the Bay of Seine: impact of floods Seine River (France)     

Sébastien Garnaud  Patrick Lesueur  Sandric Lesourd  Nicole Poupinet  Jean-Claude Brun-Cottan 《Comptes Rendus Geoscience》2002,334(5):323-330

This paper presents the first results obtained during cruises since 1995 in the southeastern part of the Bay of Seine. New sedimentological data concerning sediment samples, box cores and water column measurements have been obtained recently in the framework of the Research Programme PNEC (French National Coastal Environment Programme). Fine sediments are deposited on form of temporary veneers of fluid-to-soft mud formed during high floods episodes. In the subtidal area (<10 m water depth), mobility of fine sediments is important and temporary mud deposited during high discharge period composes part of the distal estuarine system of the Seine River. To cite this article: S. Garnaud et al., C. R. Geoscience 334 (2002) 323–330.  相似文献