V. A. Shirokov1, Yu. K. Serafimova2

1Institute of Volcanology and Seismology of the Far Eastern Branch of Russian Academy of Sciences
9, Piip Blvd., Petropavlovsk-Kamchatsky, 683006, Russia
2Kamchatkan Branch, Geophysical Survey, Russian Academy of Sciences 9, Piip Blvd., Petropavlovsk-Kamchatsky, 683006, Russia

For the first time a distribution of strong earthquakes was studied on the two-dimensional phase plane. The coordinates of this plane were both the phase of 19-year’s lunar tide and the phase of 22-year’s magnetic solar cycle. The statistically valid «dangerous» phase windows were discovered on the basis of a devising method by the data of earthquakes 1737-2006 for each of four regions of a north-west part of. The narrow «dangerous» phase range for Pacific belt earthquakes with M і 7.6 were discovered in the neighborhood of minimum epochs of 22-years’s solar cycles. In the first quarter of a current century the «dangerous» period dated to an interval October 2006 - January 2008, in which 2-6 earthquakes with M і 7.6 are expected. One of them has taken place in Kuril Islands region (15.11.2006, М=8.3). In whole, 66 from 74 earthquakes with a magnitude M і 7.6 were occurred in the «dangerous» intervals. The average alarm time for earthquakes is equal to 29.6 % of all time. According to the new approach a long-term forecast of the strong earthquakes for the 20 years immediately ahead for seismic regions (Aleutian Islands, Kamchatka, Kuril Islands and Japan) was made. The retrospective estimation of long-term forecast efficiency was made.