Faulting in outer continental shelf of southern Bering Sea

Synthesis of more than 10 000 line-km of high-resolution seismic data indicates the distribution, types, and trends of faults present on the outer continental shelf of the southern Bering Sea. Faults are classified into three types as to whether they 1) offset the sea floor (surface fault), 2) show less than 5m of displacement (minor fault), of 3) show more than 5m of displacement (major fault). The distribution of surface faults follows the outline of St George basin and suggests that the basin is presently subsiding. Minor faults are concentrated throughout St George and Amak basins but are not common elsewhere in the region. Major faults appear to be associated with the boundary faults of St George and, to a lesser extent, Amak basins. The faulting is probably a result of earthquake-induced energies that reactivate zones of weakness inherited from the collapse of the margin during the late Mesozoic-early Tertiary. -Authors