Plasma and Electromagnetic Effects Caused by the Seismic-Related Disturbances of Electric Current in the Global Circuit

This paper is devoted to the use of an electrodynamical model for lithosphere – atmosphere – ionosphere (LAI) coupling to explain plasma and electromagnetic earthquake (EQ) precursors. Our consideration is based on the calculation results of electromagnetic perturbations and ionospheric irregularities accompanying the electric field and electric current occurring in the global atmosphere – ionosphere electric circuit. Our theoretical results are confirmed by satellite- and ground-based experimental data of plasma and electromagnetic perturbations obtained for several days before an EQ. It is shown that the growth of current in the global circuit might result in the AGW (acoustic gravity wave) instability in the ionosphere, the formation of field-aligned current and plasma irregularities, magnetic field ULF oscillations and electromagnetic ELF radiation, spectral broadening of VLF transmitter signals registered by satellites, depressions of ULF magnetic pulsations, VHF radio emissions generated in the troposphere and propagation of the signals of a VHF transmitter behind the horizon. Moreover, the generation of electric current in the global circuit is accompanied with the modification of D, E and F ionospheric layers. All of these phenomena are shown to be attributed just to a single cause; namely, the variation of conducting electric current in the global circuit by the injection of charged aerosols into the atmosphere during seismic activity.