The effect of the oceans and sedimentary cover on global magnetovariational field distribution

Electromagnetic fields excited by long-period geomagnetic variations were calculated for spherical earth models with the realistic inhomogeneous surface layer. Calculations were also carried out for the model with the double inhomogeneous layer. The modelling results did not display the same level of distortions which had been observed experimentally. The revealed contradiction may be explained by a possible existence of significant inhomogeneities in the earth mantle.