Methodology of the Murman-2018 Experiment

The methodology of the Murman-2018 experiment is considered. The technique of the study is based on the distance principle of deep sounding combined with frequency and audio magnetotelluric soundings. Two mutually orthogonal grounded transmitting lines, 1.6 km and 1.9 km in length, were powered by an Energiya-4 generator, which was used as a controllable electromagnetic field source . The main focus of the paper is the description of the self-powered 29 kW Energiya-4 generator with an output voltage up to 1200 V, developed at NERC KSC RAS. The paper discusses experience of using the generator to solve of fundamental problem of studying the nature of the deep geophysical boundaries in the Archean crust of the Murmansk block in the Murman-2018 experiment. A block diagram of the Energiya-4 generator is presented and its operating principle briefly described.