Submarine Landslide

A submarine landslide is the downslope mass movement of seafloor sediment, ranging from coherent slumps that preserve internal layering to disaggregated debris flows and turbidity currents. It begins at a headwall scarp where the slope fails, evacuating material into a scar and depositing a mass-transport deposit downslope. Triggers include earthquakes, rapid sediment loading, gas-hydrate dissociation, and elevated pore pressure that lowers effective stress on the failure plane. The Storegga Slide off Norway moved roughly 3,000 cubic kilometers about 8,150 years ago and generated a tsunami. Submarine landslides threaten cables, pipelines, and coasts, and they feed sediment to deep-sea fans.