Active tectonics and origin of landslides on the Eastern Sakhalin slope

Original data obtained by bathymetric and seismic observations on the Eastern Sakhalin slope in frames of two international projects have been presented. Investigation based on these data has revealed that landslides origin may be controlled by active tectonics. Active tectonics is manifested on the slope as a system of NE and NS striking faults. Vertical displacements along the faults result in subsidence of sediments and form closed depressions in the slope relief. Failure of the depressions' steep walls may initiate sliding process. One of such landslides with volume of about 4 km3 has been mapped by the geophysical survey. Landslides of such size are capable to generate tsunami waves with height up to 10-12 m. They constitute a real threat for infrastructure of petroleum industry