STUDY ON THE RELATION OF SOLAR ACTIVITY AND STRONG EARTHQUAKES OCCURRED IN NORTH CHINA

The relation between sunspot activity cycle and over 6 magnitude earthquakes occurred in North China (108°~124°E, 34°~42°N) from 1815 to 2002 is studied with statistics.The results show that there was a good correspondence among them.Since the fourth climax, 86.6% of the strong earthquakes in North China concentrated in the peak period (±1 year) and valley period (±1 year) of the 11 years' cycle, especially in double week peak and single week valley period.There was no earthquakes occurred in the period of declining period of a single week.It is in the declining period of 23rd week at present, so the probability of earthquake in the region is very low.