Deep sounding with industrial power lines in conjunction with MTS measurements

This study is devoted to the development of a method for deep tensor electromagnetic inductive sounding of the Baltic Shield lithosphere with the use of mutually orthogonal industrial power lines alternately connected to a generator of up to 100 kW in power. The first results of the sounding are obtained at separations of up to 510 km from the source. The electrical conductivity of the Baltic Shield lithosphere in the crust-mantle transition zone (depths of 20–50 km) is numerically estimated from soundings with natural and controlled sources. The perspectives of future investigations are associated with synchronous observations on a 2-D network of measuring stations. This will enable the study of the relation of deep geoelectric parameters of the lithosphere to the geological structure of the crust in terms of 3-D models.