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Results of geoelectric mapping of some Asian countries with high seismic activity are presented. The methodology of the geoelectric mapping is considered, and the corresponding maps of geoelectric sections of Turkey, Iran, Afghanistan, Pakistan, Korea, and Japan are con- structed on a scale of 1:5 000 000. dypov et al., 1979), which systematize basic data on the elec- trical properties of rocks in terms of a homogeneous model of the medium. These maps are made with the results of measurements of field strength of LF-MF broadcasting sta- tions. They may be true at concrete frequencies of separate radio stations, but cannot be used in a wide range of frequen- cies. Works on the preparation of similar maps demand the presence of widely developed network of radio stations and greater expenses. The electric inhomogeneous geological medium distorts the amplitude-phase structure of an electromagnetic field. As bedding of the Earth's crust exerts a significant influence on the structure and level of an electromagnetic field there was a necessity of taking account of this factor. An essential in- crease in accuracy of calculations of the electromagnetic field in a wide frequency band (from VLF and up to MF-SF) be- came possible with the use of predictive maps of geoelectric sections (GES), that account for the layered structure of the underlying medium. These maps reflect the areal distribution of various GES types, with the electrical resistivity j (one is the inverse of the conductivity j=1/ j), dielectric permit- tivity "j and thickness hj specified for each layer of GES. These parameters enable the calculation of values of surface impedance , attenuation function W and field strength E in a wide range of frequencies. These values are necessary for the prediction of electromagnetic wave propagation conditions. The conductivity map of the world, compiled by Morgan and Maxwell (1965), now fails to meet practical require- ments because it is constructed using the model of a ho- mogeneous underlying medium. Significant divergences of conductivity values from their map with measurements are actually observed in some areas (Bashkuev, 1996), with elec- trical boundaries not coinciding with real electrical and geo- logical boundaries. This calls for the construction of a new predictive map of geoelectric sections of continents of the world. So the purpose of this paper is to construct the maps |
