Manifestation of Singlets of the Basic Spheroidal Mode of the Earth 0S2 in Geomagnetic Variations

Abstract

The results of instrumental observations have shown that the spectra of geomagnetic variations exhibit a quasi-harmonic component, the frequency of which is close to the basic spheroidal mode of the Earth ₀S₂. In periods 15 days long after three large earthquakes and in the absence of strong magnetic disturbances, the fine structure of this mode in geomagnetic variations is identified in the form of singlets. The frequencies of these singlets are similar to the theoretical values calculated using an ideal elastic isotropic model of the Earth of spherical symmetric form without its rotation.