Giant Seafloor Depressions Caused by Slope Failures and Bottom Currents on the Namibia Continental Margin

More than 100 circular, elongate or crescent-shaped very large seafloor depressions were found on the southern Namibian continental margin in water depths between 900 and 1700 m. These show extraordinary sizes of up to 3 km diameter 180 m depth. Multichannel seismic bathymetric data influence bottom currents their morphology through prograding infills upcurrent erosion downcurrent flanks, thus creating a crescent largest depressions. Although resembles pockmarks related fluid seepage, no indications for an active flow system observed area. Some extensive underlying cut-and-fill sequences that could be traced down slope failure structures deposits at A correlation ODP drill site 1085 indicates continuous development ∼10 Ma, documented by successive stages infilling, size variations. Analysis reflection suggests these formed interaction with existing morphology. The equilibrium was initially disturbed mass-wasting events, common occurrences region. Subsequently, ongoing sedimentation vicinity affected ocean currents, leading preservation constant re-shaping until recent times. This study highlights ability under bottom-current produce unique features over long geological time scales.