Abstract:
Evidence is presented to support the hypothesis that the natural impulsive electromagnetic field of the Earth (NIEMFE) involves pulses of lithospheric origin that are generated by seismic and microseismic ground motion. The parameters of this lithospheric NIEMFE component vary in space across structural crustal heterogeneities and show time variations due to changes in crustal mechanical stresses caused by changes in tectonic stress, tidal strain, or air pressure. Changes in the lithospheric EM component during the precursory period of a geodynamic event can be used as earthquake precursors to forecast earthquake time of occurrence, energy, and focal depth. The results of this study were tested by the forward predictions of the seismic situation in the Issyk Kul Basin area. The modulation of the NIEMFE (VLF range) by mechanical stresses is proposed for use in assessing the stress and strain of rock masses, for short-term prediction of geodynamic events, and in geophysical research.