Penetration characteristics of electromagnetic emissions from an underground seismic source into the atmosphere, ionosphere, and magnetosphere

Theoretical calculations are made on electromagnetic fields in the frequency range 10−2 to 10−2; Hz on the ground surface and above the ionosphere induced by stochastic microcurrent activity inside the future seismic sources on the assumption of cylindrical symmetry of the effective current and three types of polarization. The inhomogeneity of the ground and atmosphere conductivity and anisotropy of the ionosphere are taken into consideration. The intensity of ULF magnetic and electric precursors observed on the ground, and their spatial distribution can be explained by using the results of the present computations. It is found that only the fields from a magnetic type source can penetrate into the magnetosphere and generate propagating Alfven waves. The expected values of magnetospheric electric and magnetic field are 1‐10 μV m−1 Hz−1/2 and 1–10 pT Hz−1/2 respectively, and the horizontal scale of their distribution is about 100–200 km. Finally, these theoretical predictions are compared with the corresponding results of satellite observations.