**4.1.1 Seismic region and data**

The region under study in case 1 includes the Kuril Islands zone and the area to the east of Hokkaido Island. In 1992 we have prepared in computing form the earthquake M ≥ 4.0 catalog of the Kuril-Okhotsk region for the period 1962-1990. It was formed on the basis of yearly publications (The earthquakes in USSR…, 1964-1991). During the next years the catalog was updated by the Operative catalog data of the Sakhalin Branch of Geophysical Survey of the RAS. We used this regional catalog for testing the M8 algorithm (Keilis-Borok & Kossobokov, 1986, 1990) which provided a suitable procedure for prediction of large earthquakes.
