Advective interfacial exchange in permeable sediments driven by surface gravity waves and its ecological consequences.

Abstract

Sandy sediments, as they are common in coastal and shelf environments, are highly permeable and allow advective pore water exchange across the sediment-water interface driven by pressure differences at the sediment surface (Huettel and Webster 2001). This process has been addressed and quantified for unidirectional flow in a number of studies, and it has been suggested that advective exchange may play a significant role in global biogeochemical cycling of matter (Huettel et al. 1998), as permeable sediments are abundant on the continental shelves (de Haas et al. 2002). Advective exchange driven by oscillating flows, as induced by surface gravity waves in shallow water, has received less attention in previous works although waves affect large areas of the global shelves. The aim of this thesis was to investigate and quantify advective exchange between permeable sediments and overlying water driven by surface gravity waves and to demonstrate the influence of this exchange on the sedimentary oxygen dynamics.