Wave-sediment interaction on a muddy inner shelf during Hurricane Claudette

Measurements of wave and suspended sediment concentration (SSC) were conducted near the 5-m isobath on the muddy inner shelf fronting Atchafalaya Bay, Louisiana, during Hurricane Claudette. The data show that wave and current activity resuspended large quantities of sediment, with SSC >= 0.5 kg/m(3) throughout the water column. In the waning phase of the storm, settling generated a suspension layer, with concentrations over 1.7 kg/m(3) measured as high as 1 m above the bottom. Numerical simulations of post-storm sediment settling showed that observations are consistent with a high-density fluid mud layer (SSC between 10 and 20 kg/m(3)), and separated from the upper water column by a lutocline located at about I m above the bottom. The formation of the fluid-mud layer is correlated with strong, broad-spectrum wave dissipation, consistent with the hypothesis that surface-interface wave interaction plays an important part in the energy transfer from the surface to the soft bottom. (c) 2004 Elsevier Ltd. All rights reserved.