ИСТИНА

The effectiveness of monitoring electromagnetic precursors of earthquakes largely depends on the choice of the most "sensitive" observation points. On the other hand, the electromagnetic response of the earth's crust to seismic waves is determined by the local mechano-electric properties of the earth's crust. Thus, preliminary sounding of a seismically active region with seismic waves from an explosion using simultaneous seismic and electromagnetic observations could indicate the most promising observation points for monitoring electromagnetic precursors. However, reliable extraction of the necessary information requires a clear physical understanding of the various mechanisms of the magnetic response to acoustic impact on geophysical media. Some of these mechanisms are examined in this report. Seismoelectric effect of the second type is a phenomenon of the electromagnetic field excitation in a porous moisture-saturated medium during the propagation of the seismic waves in this medium. Electromagnetic fields created by this effect can provide critical information about the parameters of the porous medium, for instance: depth of the moisture-saturated rock, electrokinetic coefficient, fluid content, porosity, and others. In this report we use simultaneous seismic, electromagnetic, and telluric variations that accompany seismic waves. The high-sampling measurements have been performed at the geophysical observatory «Karymshina» at Kamchatka to extract the parameters of the porous medium. This study was supported by grant 22-17-00125 from the Russian Science Foundation.