Temporal changeability of connections between the Earth's seismic activity and the cycles of solar activity of different duration
© I.P. Shestopalov, E.P. Kharin
The data on seismic energy liberated from the earthquakes foci all over the globe during the period since 1680 up to 2002 have been analyzed in comparison with solar activity cycles and geomagnetic disturbances. The base of the study comprises the notion of seismic activity as a part of united physical process in the system "Sun-Earth". In this case seismic phenomena are determined by the processes of both terrestrial and solar origin. There are 11-year cycles of seismic activity on the Earth. Cyclic changes of geomagnetic activity with duration of three solar cycles and secular ones have also been identified. Correlation between solar and seismic activity is prevailingly negative, under the action of strong solar proton events or other yet unknown reasons this correlation can be positive. The strongest earthquakes take place at the beginning of secular cycle. In the 1990-ies of the last century new secular cycle began with expected strong seismic activity at the beginning during several tens of years. The earthquakes on 26.12.2004 with M=9 and on 21.03.2005 with M=8,5 in the region of Indonesia confirm this conclusion.