© Yu. K. Serafimova

Kamchatkan Branch, Geophysical Survey, Russian Academy of Sciences
683006, Petropavlovsk-Kamchatsky, Piip Avenue 9, Russia

A research is conducted of interrelation between powerful earthquakes (MW і 7.5) taken place in Kam-chatka with sunspot number variations. An evaluation of this relation is made for four phases designated in 11-year sun’s activity cycle. It has been revealed that such a relation exists and is mostly evident for phases corresponding to maximum and minimum of sun’s activity cycle. A retrospective analysis of earthquake forecast efficiency on phases of sun’s activity cycle shows that presence of phases corresponding to maximum and minimum of sun’s activity cycle can serve as qualitative additional criteria at a real-time middle-term forecasting of powerful Kamchatkan earthquakes.