## 4 Discussion  
It is suggested that the Sun may provoke earthquakes during substantial increases in solar wind activity. Statistical studies show that geomagnetic storms may precede strong earthquakes and that the time delay between a storm's onset and an earthquake's occurrence may vary from some days to some months. Since the efficiency of penetration of solar wind energy into near-Earth space changes with season and time (Russell-McPherron mechanism), it seemed appropriate to compare the response of the Earth's seismic activity to somewhat similar geomagnetic storms. For this purpose, we chose the two strongest geomagnetic storms in the 24 th solar cycle, which occurred on the same day on 17 March 2013 (SYM/H index = \(-\)132 nT) and 17 March 2015 (SYM/H index = \(-\)234 nT). The storms occurred at relatively close solar flux levels (F\({}_{10.7}\) = 118, F\({}_{10.7}\) = 126, respectively) and were responsible for somewhat similar peak values of the auroral electrojet index (AE) equal to 2700 nT and 2200 nT, respectively. The times of these magnetic storm onsets were also similar: 06:04 UTC for the storm on 17 March 2013 and 04:48 UTC for the storm on 17 March 2015. The shapes of the main and the recovery phases for these storms were identical (Figure 4). The variations of daily released seismic energy around the globe from 17 March to 17 June in 2013 and 2015 showed that two peaks in seismic energy took place for both years--one in April and another in May (Figure 5). The major and great earthquakes mainly responsible for these peaks occurred in almost the same territories in 2013 and 2015. Namely, on 16 April 2013, the crust M = 7.7 earthquake occurred in Iran with a time delay of 30 days, and on 25 April 2015, the crust M = 7.8 earthquake occurred in Nepal with a time delay of 39 days. Then, on 24 May 2013, the deep-focus M = 8.3 earthquake occurred beneath the Okhotsk Sea (Russia) with a  
Figure 9: A histogram of the distribution of the number of (M \(\geq\) 7.5) earthquakes that occurred around the globe in 1973–2017 (212 events) dependent on the longitude locations of the magnetic poles in the Northern and Southern Hemispheres for three options: 1—geomagnetic poles (quadrants), 2—magnetic dip-poles (stars), and 3—corrected geomagnetic poles (pentagon), respectively. time delay of 68 days, and on 30 May 2015, the deep-focus M = 7.8 earthquake occurred beneath the Pacific Ocean (Japan) with a time delay of 74 days. It has been known for more than 30 years that the process of earthquake preparation modifies the state of the atmosphere and ionosphere, e.g., (48) (and references herein). The time delay between the appearance of an anomaly in the atmosphere-ionosphere parameters and earthquake occurrence may differ. For example, the multiparameter satellite data analysis revealed anomalous atmospheric and ionospheric effects over the earthquake preparation zone of the Nepal M7.8 earthquake 21 days before 25 April 2015, the main shock (49). It was found in (26) that strong earthquakes may occur near the footprints of geomagnetic lines that were intensely populated with high-energy particles. In the areas of the polar cusps, where the solar wind plasma has direct access to the Earth's environment, the geomagnetic lines can be filled by solar wind plasma, especially in the time of a shocked solar wind arrival. Since the longitudinal extension of the polar cusp is restricted by 08 h-16 h MLT (37), one may expect that shocked solar wind will provoke earthquakes mainly in those longitudinal regions in which high-latitudinal areas are located under the polar cusp at the time of a shocked solar wind arrival. Table 2 shows that this was right for all M \(\geq\) 7.5 earthquakes that occurred in 2013 and 2015. It was shown in (16) that this was also right for all (nine) strong M \(\geq\) 7.0 earthquakes that occurred in 1967-2023 inside and around the Anatolian plate, including the catastrophic M = 7.8 and M = 7.5 Kahramanmaras earthquake sequence in Turkey on 6 February 2023.