Geophysical Journal | 2008 volume 30 6

Electromagnetic emission of lithosphere: spatial structure and possible mechanisms of generation

© V.N. Shuman, Yu. A. Bogdanov

The studies of mechanisms of generation of spontaneous signals of lithospheric origin of kilohertz (radiowave) range, being registered on the earth's surface have been continued within the limits of the known model of distributed excitable geomedium as a system of rigid lithospheric blocks, divided by fault and fracture zones, taking into account the theory of propagating along these zones "captured" waves (generalized Relay waves). Attention is being paid to multiplicity of possible mechanisms of mechanoelectromagnetic transformations within geological medium. It is evident that transient radiation in non-stationary geomedium, generated by the field of charges in a wave of complicated dielectric permeability, which is formed of the front of the "captured" wave, canalized by the fault can be included in their number. As a result, within the limits of the considered model of excitable geomedium it becomes possible carrying out of electromagnetic noise of radiowave range from the sites of its generation to the earth's surface that eliminates the known difficulties in perception of this idea. The problems of correlation of the forms of anomalies of intensity of spontaneous electromagnetic disturbances of radiowave range registered on the interface ground-air with geometric features of some geostructures are being discussed. It has been found, in particular, that spatial parameters (scales) of anomalies of intensities do not practically depend on distribution of geoelectric characteristics (specific conductivity, dielectric and magnetic permeability) of the section but are determined by the depth of sinking of "radiating element". Practical examples of application of the method for diagnostics of geostructures are being given.

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