CRUST CLASSIFICATION AND SEISMIC POTENTIAL OF SAKHALIN

Abstract

A new map of earthquake hazard zonation is proposed for Sakhalin Island and adjacent offshore area in terms of maximum possible earthquakes. The map was made using a new extraregional seismotectonic method developed at the United Institute of Physics of the Earth, Russian Academy of Sciences. The method relies on a seismotectonic zonation of the crust independently of any seismological data, the zonation being based on the present-day crustal structure and condition, that is, on the zonation of the crust where the present-day seismic process may be going on. The results of this zonation are compared with available seismological materials to find an appropriate M(max) value for each seismotectonic setting and ascribe it to regions that have a similar seismotectonic setting. The map was prepared for the region of Okhotia, which covers the Sea of Okhotsk with Sakhalin and Primorye in the west, the Kurils and Kamchatka in the east and southeast, and the extreme northeastern part of North Eurasia. The map is appreciably different from those available at present for Sakhalin I. and adjacent offshore areas and may be useful in the preparation of a new map of seismic zonation for the region.