## 2 Data and Methods  
For analysis, we used data from the USGS Global Seismological Catalog ([[https://earthquake.usgs.gov/earthquake](https://earthquake.usgs.gov/earthquake)]([https://earthquake.usgs.gov/earthquake](https://earthquake.usgs.gov/earthquake)), accessed on 25 October 2018) for 1973-2017 for earthquakes with a magnitude of M \(\geq\) 4.5 (more than 220,000 events). For the epicenters of all analyzed earthquakes, we calculated the values of the McIlvaine parameter L [32] (indicating the distance of geomagnetic lines to the center of the Earth at the equator, expressed in terms of the radii of the Earth) using the IGRF model and the computer codes of the GEOPACK [33]. The McIlwain parameter (L)--is named after the scientist [PERSON] and has two more names: (L-shell), magnetic shell; (L-value), number of the magnetic field line)--is taken to be equal to the ratio of the average distance of the geomagnetic shell (geomagnetic field line) from the center of the Earth in the plane from the geomagnetic equator to the radius of the Earth. The equation for calculating the value of L at a point with geographic coordinates (\(\lambda\), \(\varphi\)) is \(L=Re(\lambda,\varphi)/Recos^{2}\Lambda\), where \(\lambda\) is geographic latitude, \(\varphi\) is geographic longitude, \(\Lambda\) is geomagnetic latitude, and \(Re\) is the radius of the Earth at the equator. The equation for calculating the radius of the Earth at a point with geographic coordinates (\(\lambda\), \(\varphi\)) is \(Re(\lambda\), \(\varphi)=\alpha+b\) cos\({}^{2}\)\(\lambda+c\) cos\({}^{4}\)\(\lambda\), where \(\alpha\) = 6356.912 km is the radius of the Earth at the geographic pole, \(b\) = 21.3677 km, and \(c\) = 0.108 km. The value of geomagnetic latitude at a point with geographic coordinates (\(\lambda\), \(\varphi\)) can be obtained from the equation sin\(\Lambda\) = sin \(\lambda\) sin \(\lambda_{p}\) + cos \(\lambda\) cos \(\lambda_{p}\) cos (\(\varphi-\varphi_{p}\)), where \(\lambda_{p}\), \(\varphi_{p}\) are the geographic latitude and longitude of the geomagnetic pole; these change over time (secular variations of the geomagnetic field), which is reflected in the international reference model IGRF, which describes the main geomagnetic field and its secular variations produced by an internal source located in the liquid outer core of the Earth. A geomagnetic storm is an interval of several days during which there is a significant reduction in the horizontal component of the geomagnetic field at the Earth's surface [34]. Following [35], geomagnetic storms may be small (Dst from \(-30\) to \(-50\) nT), moderate (Dst from \(-50\) to \(-100\) nT), strong (Dst from \(-100\) to \(-200\) nT), powerful (Dst from \(-200\) to \(-350\) nT), and extra strong (giant) (Dst lower than \(-350\) nT). We investigate the response of seismic activity to geomagnetic storms, and the data for the disturbance storm (Dst index) were obtained from NASA/GSFC's Space Physics Data Facility's CDAWeb service and OMNI data ([[https://cdaweb.gsfc.nasa.gov/index.html](https://cdaweb.gsfc.nasa.gov/index.html)]([https://cdaweb.gsfc.nasa.gov/index.html](https://cdaweb.gsfc.nasa.gov/index.html)), accessed on 30 September 2023). Geomagnetic storms, the bright manifestation of space weather variations, influence the Earth's radiation belts (toroids of very high-energy magnetically trapped charged particles), as discovered in 1958 by [PERSON] [36]. Radiation belts typically comprise two distinct zones (inner and outer) spatially separated by the slot region (Figure 1 from [37]). The inner Van Allen zone, mainly populated by energetic protons, extends from just above the dense atmosphere to an equatorial altitude of about 10,000 km above the Earth's surface. The left label in Figure 1 shows several space weather concerns for the inner radiation belt zone [37]: the intense, high-energy trapped protons, the variable, trapped solar energetic particles, the trapped galactic cosmic rays, and the trapped energetic electrons.