Slope instability along the western margin of the Antarctic Peninsula

Extensive multibeam mapping and sub-seafloor data from multichannel reflection-seismic surveys highlight the main morphological characteristics on the continental slope and rise of the western margin of the Antarctic Peninsula. These data provide evidence for several types of Neogene and Quaternary seafloor instability. This continental margin is atypical in its Cenozoic tectonic and sedimentary evolution because it changed from active to passive and sedimentation underwent a transition from river-dominated to glacial-dominated as the Antarctic Ice Sheet began to form (Eocene–Oligocene). The modern morphology of continental rise is characterized by the presence of sediment mounds, interpreted as sediment drifts orientated perpendicular to the margin. The drifts exhibit common features: they are located between shelf lobes and display a steep flank towards the SW and a gentle flank towards the NE. Despite the steepness of the slope, sediment failures occur mainly on the continental rise (Volpi et al. 2011).