Magnetic and Ionospheric Effects of a Series of Strong Earthquakes on April 2‒3, 2024 (Taiwan)

The disturbances of the geomagnetic field in the surface atmosphere were considered during a series of strong earthquakes that occurred on April 2–3, 2024, in the vicinity of the island of Taiwan. The data from the Mikhnevo Geophysical Observatory of the Sadovskii Institute of Geosphere Dynamics, Russian Academy of Sciences, and the observatories of the international INTERMAGNET network were analyzed. It was shown that in the absence of sole-related 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 four hours. The delay time of the magnetic effect relative to the main shock of the first earthquake was ~60 min. The ionospheric effect of the event considered was established in the form of variations in the critical frequency of the F2 layer of the ionosphere on the basis the ionograms of height–frequency sounding obtained at the Okinawa ionospheric monitoring station and freely available on the website of the Japanese National Institute of Information and Communication Technologies.