Geotechnical characterization of surficial high-porosity sediments in Eckernforde Bay

Geotechnical studies of high-porosity, fine-grained sediments from Eckernforde Bay, part of the Coastal Benthic Boundary Layer program, included coring, subsampling, and on-board testing during three field experiments, and a laboratory testing program to determine the mechanical properties of the seabed. The sediments consist of high-porosity (86-94%), organic-rich (10-20%) silty clays with varying amounts of methane gas. The surface 5-10 cm are characterized by unusually high water contents (400-600%), very low shear strengths (<1 kPa), and pronounced shear thinning behavior. Below that depth sediments are somewhat more competent, exhibiting water contents of 250-300% and higher strengths (>1 kPa).