Discussion paper: Electrostriction and magnetostriction...

3. Is the Seismic Activity of the Earth Associated With the IMF Sign Reversal?

Figure 6

[5] In order to estimate the degree of deformation of the Earth's crust at the IMF polarity reversal and crossing of the high-speed solar wind streams by the Earth and to understand whether the Earth's seismic activity can be initiated in this case, we plotted the distribution of the earthquakes with magnitudes m(b) >6.3 detected over the Earth in 1970-1992 versus the interval between the day of the earthquake and the nearest day of the IMF polarity reversal near the Earth. The number of the earthquakes with magnitudes m(b) > 6.3 was 210 during this period. The obtained distribution is shown in Figure 6. The distribution maximum is seen to coincide with the day of the IMF polarity reversal. The distribution includes 144 earthquakes. The total number of the earthquakes in Figure 6 is limited because of insufficient data on the IMF polarity reversal near the Earth (the information was retrieved from http://www.srl.caltech.edu). The information about the earthquakes was taken from the Global database designed by the US Geological Survey National Earthquake Information Center. In order to understand the nature of the obtained distribution, we plotted another distribution versus the interval between an arbitrarily selected day and the nearest day of the IMF polarity reversal near the Earth. The arbitrary days were chosen to be the first days of all the months in 1970-1992. Of 276 days selected in such a way, only three days coincided with the days of the earthquakes with magnitudes m(b) > 6.3. The

Figure 7

obtained distribution is presented in Figure 7. The distribution includes 209 days, for 67 days the information on the IMF polarity was not available (the data on the IMF polarity were taken from the source mentioned above). If the distributions given in Figures 6 and 7 are reduced to the same statistics and statistical errors are taken into account, the distributions turn out to be similar to each other. This means that the seismic activity of the Earth is in no way associated with the IMF sign reversal. The obtained distributions simply demonstrate a randomness in the distribution of the IMF polarity reversals near the Earth.