Linking surficial geomorphology with vertical structure in high and low energy marine environments

Abstract

[author abstract] Puget Sound is a complex system of high energy river inputs to lower energy large basins with direct connection to the open ocean through the Straits of Juan de Fuca. Using a high resolution bathymetric surface derived from multibeam sonar synchronized with low frequency sub-bottom acoustic profiles, the depth of acoustic penetration is correlated with a focal calculation of seafloor roughness. Observable differences in the sub-bottom data indicate an association between higher energy systems, such as the Elwha River, with harder sediments and lower ranges of depth recorded with acoustic profiles, with lower energy systems, such as South Possession Sound, indicating softer sediments and higher ranges of depth. Seafloor roughness at these high and low energy sites are nearly identical, indicating that the surficial layer masks the vertical structure of the seafloor.