Abstract
Based on the analysis of data from the Mikhnevo geophysical observatory of the IDG RAS and a number of observatories of the international INTERMAGNET network, the disturbances of the geomagnetic field in the surface atmosphere were considered during a series of strong earthquakes that occurred on April 02–03, 2024 in the vicinity of the island of Taiwan. It is shown that in the absence of significant global disturbances of the Earth’s magnetic field, earthquakes were accompanied by geomagnetic variations with a maximum amplitude of ∼10 nT and a total duration of about 4 hours. The delay time of the magnetic effect relative to the main shock of the first earthquake was ∼60 minutes. Based on the results of processing ionograms of height-frequency sounding obtained at the Okinawa ionospheric monitoring station and freely available on the website of the Japan National Institute of Information and Communication Technologies, the ionospheric effect of the event in question was established in the form of variations in the critical frequency of the F2 layer of the ionosphere.