Solute Exchange by Convection Within Estuarine Sediments

The rates of material transport through sediments are central to determining the biochemical status of sediments. Transport within sediments can occur by molecular diffusion through porewaters and by the activities of burrowing biological organisms, but a number of physical processes can enhance transport within porewaters. Here, convection is investigated as a mechanism for solute transport within sediments. Convection will occur as the gravitational adjustment to the occurrence of porewater which is of lower salinity and density than the water at the sediment surface. This process could be important for exchange between sediments and the water column in regions subject to significant temporal variations in salinity such as estuaries.