Sedimentological and geotechnical properties of fine-grained sediments in part of the South Sea, Korea

Sedimentary characteristics and geotechnical properties of the fine-grained sediments in the South Sea were analysed on 45 sediment cores collected in part of the sea. A map of surface sediment distribution in the sea is newly presented, based on the compilation of previous localized data. Grain size of the sediment (7–9ϕ) decreases slightly but systematically with water depth, although some variations in size occur locally along the coastal area. Shear strength is substantial near the sea floor (3–5 kPa) and gradually increases downcore, indicative of slow sedimentation. Water content is largely over 100% and uniform vertically. Organic matter and CaCO 3 increase Atterberg limits of the sediment, which is highlighted in the sediment off Ulsan under the influence of coastal upwelling.