THE “MURMAN-2018” EXPERIMENT TECHNIQUE
M.B. Barannik
Center
for Physical and Technical Problems of Energy of the North
– a
Branch
FRC
“Kola Science Center
of the Russian Academy of Sciences”,
Murmansk region, Apatity, Russia
e-mail: maxbarien@mail.ru
Highlights
During the “Murman-2018” experiment direct current (DC) soundings and Controlled Source Audio-Magnetotellurics (CSAMT) soundings in combination with audio magnetotelluric (AMT) soundings in natural fields were performed
The DC and CSAMT soundings were carried out in the fields of two mutually orthogonal grounded supply lines 1.9 and 1.6 km long, the controlled current source for which was the improved 29 kW “Energia-4” generator, powered by two DC generators
The feature of the “Energy-4” generator is the pulse width modulation technique-based inverter. A periodic current of the required shape, was formed: a meander for DC soundings; sinusoidal current in the frequency range from 4 to 2000 Hz for CSAMT soundings
The developed switching scheme of the DC generators and the use of a step-up transformer at frequencies above 50 Hz made it possible to increase the output voltage of the generator to 1000–1200 V. Accordingly, the current in the transmitting lines with the total resistance of 55–57 Ω was 10–20 A, depending on the frequency. Together with the algorithms used for the stackings and processing of the measurement information, this made it possible to increase the source-receiver separation up to 110 km
Abstract. The methodology of the “Murman-2018” experiment is considered. The technique of the study is based on the distance principle of the deep sounding in combination with frequency and audio magnetotelluric soundings. Two mutually orthogonal grounded transmitting lines 1.6 km and 1.9 km in length powered by the “Energy-4” generator that was used as a controllable source of the electromagnetic field. The main focus of the paper is the description of the self-powered 29 kW “Energy-4” generator with output voltage up to 1200 V, developed at the NERC KSC RAC. The experience of using the generator for the solution of the fundamental problem of studying the nature of the deep geophysical boundaries in the Archaean crystalline crust of the Murmansk block in the “Murman-2018” experiment is discussed. Block diagram and operation principle of the “Energy-4” generator are briefly given in the paper.
Keywords: controlled current source, pulse width modulation inverter, grounded transmitting line, frequency sounding, distance sounding
Cite this article as: Barannik M.B. The “Murman-2018” experiment technique, Nauka i Tekhnologicheskie razrabotki (Science and Technological Developments), 2019, vol. 98, no. 4, pp. 50–56. [Special issue “Methodological developments for electromagnetic controlled source soundings”]. [in Russian]. https://doi.org/ 10.21455/std2019.4-5
References
Barannik M.B., Danilin A.N., Efimov B.V., Kolobov V.V., Prokopchuk P.I., Selivanov V.N., Shevtsov A.N., Kopytenko Yu.A., Zhamaletdinov A.A. High-voltage power inverter of the generator “Energy-2” for electromagnetic soundings and monitoring of the earthquake source zones, Seismic Instruments, 2010, vol. 46, no. 1, pp. 49–61.
Kolobov V.V., Kuklin D.N., Shevtsov A.N., Zhamaletdinov A.A. The KVVN_7 multifunction digital measuring station for electromagnetic monitoring of seismoactive zones, Seismic Instruments, 2012, vol. 48, no. 1, pp. 75–84, https://doi.org/10.3103/S0747923912010069
Kolobov V.V., Barannik M.B., Efimov B.V., Zhamaletdinov A.A., Shevtsov A.N., Kopytenko Yu.A. Energy-4 Generator for monitoring seismically active regions and electromagnetic sounding of the Earth’s crust. Experience of application in the Kovdor-2015 Experiment, Seismic Instruments, 2018a, vol. 54, no. 3, pp. 268–280, https://doi.org/10.3103/ S0747923918030143
Kolobov V.V, Barannik M.B., Ivonin V.V., Selivanov V.N., Zhamaletdinov A.A., Shevtsov A.N., Skorokhodov A.A. Experience of generator “Energy-4” application for the distance and frequency electromagnetic soundings in the experiment “Murman-2018”, Proceedings of Kola Science Centre of RAS, 2018b, no. 17, pp. 7–20, https://doi.org/10.25702/KSC.2307-5252.2018.9.8.7-20
Zhamaletdinov A.A., Velikhov E.P., Shevtsov A.N., Kolobov V.V., Kolesnikov V.E., Skorokhodov A.A., Korotkova T.G., Ivonin V.V., Ryazantsev P.A., Birulya M.A. The Kovdor-2015 Experiment: Study of the parameters of a conductive layer of dilatancy–diffusion nature (DD layer) in the Archaean Crystalline Basement of the Baltic Shield, Doklady Earth Sciences, 2017, vol. 474, no. 2, pp. 641–645, https://doi.org/10.1134/S1028334X17060095
Zhamaletdinov A.A., Velikhov E.P., Shevtsov A.N., Skorokhodov A.A., Kolobov V.V., Ivonin V.V., Kolesnikov V.E. The Murman-2018 Experiment on remote sensing in order to study the “impenetrability” boundary at the transition between brittle and plastic states of the crystalline Earth’s crust, Doklady Earth Sciences, 2019, 486, pp. 575–579, https://doi.org/10.1134/ S1028334X19050301
About the author
BARANNIK Maksim Borisovich – Researcher, Center for Physical and Technical Problems of Energy of the North – a Branch FRC “Kola Science Center of the Russian Academy of Sciences”. Russia, 184209, Murmansk region, Apatity, microdistrict Akademgorodok, 21A. Tel.: +7(921) 735-74-74. E-mail: maxbarien@mail.ru