Electromagnetic manifestation of lithosphere in ULF-VLF-range
© Uvarov V.N.
Brief analysis of the current state of research in natural electromagnetic field at the Earth's surface in the SLF-VLF range has
been conducted. A set of estimations of field levels ratios of lithospheric and storm origin has been made. It has been shown
that the level of electromagnetic field of lithospheric origin is several orders of magnitude smaller than that one of storm origin.
Justification for the use of a quadruple antenna is made, which distinguishes signals of closely spaced sources. These sources
are most likely of lithospheric origin in case of high microseismicity and absence of other sources. Some results of such
measurements are given. A brief review and analysis of existing passive methods of electromagnetic geophysical exploration
has been conducted. It has been shown that the methods based on the averaged binarization, mainly contain the fluctuating
part of natural electromagnetic field.