On the relationship between cosmic rays, solar activity and powerful earthquakes.

2No affiliation Abstract. In this paper we analyze the correlation of magnitude> 7.8 earthquakes to cosmic rays intensity. The correlation is far from simple and obvious but appears to hold for all but three earthquakes of magnitude> 7.8 since 1900. As a prequel to our study we analyze the correlation between the cosmic rays intensity and solar activity and its possible implications. We also show that magnitude> 7.8 earthquakes appear in groups; although the earthquakes of a group may appear in different places of the Earth, the time interval between two adjacent elements of the groups stays more or less the same. §1. The cosmic ray intensity and sunspot numbers. The relationship between the cosmic ray intensity (hereafter abbreviated as CRI) and the sunspot numbers (hereafter abbreviated as SSN) is well-known; high SSN correlates with low CRI, and vice versa as shown in Figure 1. The cosmic rays originate mainly outside of the Solar System, their intensity near Earth is currently believed to be modulated by cyclical solar activity with the average cycle of about 11 years long. We will refer to the eleven-year long cycles as primary solar cycles whenever there is a need to distinguish them from other cycles. The physical mechanism of the solar activity is unknown but is currently believed to be solely of purely solar origin. A bit more careful analysis of Figure 1, however, shows that the maxima/minima of CRI lag the minima/maxima of SSN by a few months. The reason for the time lag is quite obvious and is explained in Figure 2. It is currently believed that the solar activity modulates the flow of cosmic rays near the Earth but is not affected by them, which may not be the case. To understand why let us consider 1 a