ANOMALIES IN THE BEHAVIOR OF COMPONENTS OF THE EARTH’S ELECTROMAGNETIC FIELD AND THEIR RELATIONSHIP TO EARTHQUAKES ACCORDING TO MAGNETOTELLURIC MONITORING DATA

When studying the relationship between electromagnetic and deformation processes, according to the results of magnetotelluric monitoring, electromagnetic pulses were detected, which may be associated with the earthquakes that occurred. The observations were carried out at two magnetotelluric stationary monitoring points located in the Chu depression (Aksu 42.60911 °N, 74.00833 °E; Chon-Kurchak 42.62828 °N, 74.60671 °E, Northern Tien Shan), on the territory of the Bishkek geodynamic polygon. To identify earthquake responses, the results of instrumental observations of the electromagnetic effects of a strong earthquake and its aftershocks that occurred in northern China on January 22, 2024 with a magnitude in the range of 4.9–6.9, a weaker one with a magnitude of 5.4 (Kyrgyzstan) and a number of powerful remote earthquakes with a magnitude in the range of 5.2–6.6 at a distance of 500–1200 km from the epicenter were analyzed. It is shown that an earthquake with numerous aftershocks located at distances from ~450 km from the registration points is reflected in all recorded parameters, while a weaker earthquake, but located closer, does not manifest itself in one of the horizontal components of the electromagnetic field. The mechanisms of occurrence of seismoelectric signals and mechanical-electromagnetic transformations in the Earth’s crust are considered. The reality of the appearance of electromagnetic precursors of earthquakes and coseismic signals observed in the first tens of seconds or minutes after an earthquake is shown. The results of the research can be used in the development of methods for monitoring seismic activity in potentially dangerous regions.