Investigation of the geoelectrical structure of the Earth’s crust by phase-gradient sounding

• Published in: Doklady earth sciences 2015-05, Vol.462 (1), p.539-542
• Main Authors: Kopytenko, Yu. A., Ismagilov, V. S., Petrishchev, M. S.
• Format: Article
• Language: English
• Subjects: Crust; Earth; Earth and Environmental Science; Earth Sciences; Electric fields; Electromagnetic fields; Electromagnetism; Geology; Geophysics; Global positioning systems; GPS; Investigations; Ionosphere; Magnetism; Radio waves; Wave propagation
• ISSN: 1028-334X; 1531-8354
• DOI: 10.1134/S1028334X15050232

Earths crust by analyzing the natural electromagnetic field has successfully used magnetotelluric sounding (MTS) for many decades. Due to the exten sive electrification of different regions, the level of electromagnetic noise has considerably increased and this complicates recording of natural magnetotelluric currents and adequate interpretation of the MTS data. Based on the measurements of gradients and phase velocities of natural magnetic disturbance propagation carried out, Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences, St. Petersburg Branch (SPbF IZMIRAN), has developed a method of phase gradient sounding (PGS) that does not require telluric currents to be recorded. PGS implies synchronous (with GPS/GLONASS referencing) observations at spaced highly sensitive base magnetic stations located in the angles of triangles. In the center of the triangle, we can construct vectors of the gradient and phase velocity of propagation of geomagnetic dis turbances along the Earths surface and calculate the apparent resistivity of the Earths crust in different fre quency bands. To increase the amount of sounding points, it is reasonable to use a special arrangement of five to nine stations (envelope type), with one station being located in the center, while the others are located on the perimeter of the envelope.