Modern magnetotelluric researches of the Ukrainian Carpathians
Received: October 12, 2021
Subbotin Institute of Geophysics of National Academy of Sciences of Ukraine
Subbotin Institute of Geophysics of National Academy of Sciences of Ukraine
Subbotin Institute of Geophysics of National Academy of Sciences of Ukraine
Subbotin Institute of Geophysics of National Academy of Sciences of Ukraine

In order to study the deep structure of the southwestern Ukrainian Carpathians, where the Carpathian conductivity anomaly is located, in 2015 and 2020, modern synchronous magnetotelluric studies were carried out on the profiles of Mukachevo-Skole, Seredne-Borynya and Karpatsky at twenty-three points and the spatiotemporal distribution and the electric field on the Earth's surface, which can be used to assess the conductivity and geoelectrical structure of the region, was obtained. Processing of experimental data was performed using the software PRC_MTMV, which provides a common noise-canceling impedance estimation for synchronous magnetotellurical recordings. Curves of apparent electrical resistivity (amplitude values and phases of impedance) from 10 to 10000 s were obtained reliably. A joint analysis of the apparent resistivity and impedance phases and the formal interpretation of the deep magnetotellurical sounding curves using the Niblett transformation indicate the presence of the spatially inhomogeneous conductor both in the earth's crust and in the upper part of the upper mantle. The chain of local conductive sections in the earth's crust coincides with the axial part of the Carpathian conductivity anomaly. High conductivity of the upper mantle was recorded in the Ukrainian Carpathians from the Transcarpathian Depression to the Skiba cover. It is shown that it is not a homogeneous layer, there is a general deepening of the upper edge to the northeast from 40-60 km (Transcarpathian depression) to 90-100 km (Krosno cover). Sharp deepening along the Porkulets and Dukla covers is revealed. Information about the existence of a deep conductor and its parameters should be the basis for quantitative interpretation and construction of the 3D deep geoelectrical model.

1. Acta Geodatica, Geophysica et Montanistica Hungarica. (1984). Akadeviai Kiado, Budapest, 19(1-2), 188.
2. Adam, A., (Ed.). (1976). Geoelectric and Geothermal studies (East-Central Europe, Soviet Asia). KAPG Geophysical monography. Akadeviai Kiado, Budapest. 752.
3. Berdichevsky, M.N., and Dmitriev, V.I. (2009). Models and Methods of Magnetotellurics [Modeli i metody magnitotelluriki]. Moscow, Scientific World. 668. (in Russian).
4. Burakhovich, T. K. (2004). Quasi-three-dimensional geoelectric model of the Carpathian region. Geophysical Jornal, 26(4), 63-74. (in Rusіian).
5. Gordienko, V. V., Gordienko, I. V., Zavgorodnyaya, O. V., Kovachikova, S., Logvinov, I. M., Tarasov, V. ., Usenko, O. V. (2011). Ukrainian Carpathians (geophysics, deep processes) [Ukrainskiye Karpaty (geofizika, glubinnyye protsessy)]. Kiev, Logos. 128. (in Russian).
6. Kováčiková, S., Logvinov, I., Nazarevych, A., Nazarevych, L., Pek, J., Tarasov, V., & Kalenda, P. (2016). Seismic activity and deep conductivity structure of the Eastern Carpathians Stud. Studia Geophysica et Geodaetica, 60(2), 280-296.
7. Kováčiková, S., Logvinov, I., & Tarasov, V. (2019). The relation of the seismicity in the eastern part of the Ukramian Carpathian and the conductivity distribution in the Earth's crust. Geologica Carpathica, 70(6), 483-493.
8. Glushko, V. V., Kruglov, S. S. (Ed.). (1986). Tectonic map of the. Ukrainian Carpathians. Scale 1:2000000. [Tektonicheskaya karta Ukrainskikh Karpat. Masshtab 1:200000]. Kyiv, Mingeo Ukrainian SSR. (in Rusіian).
9. Murovska, G. V. (2019). Deep structure and alpine geodynamics of the Carpathian and Crimean-Black Sea regions of Ukraine [Hlybynna budova ta alʹpiysʹka heodynamika Karpat·sʹkoho ta Krymsʹko-Chornomorsʹkoho rehioniv Ukrayiny]. The manuscript on qualifying scientific work. Qualifying scientific work on the rights of manuscript. The doctor of geological sciences thesis in speciality 04.00.22 geophysics. Institute of Geophysics of NAS of Ukraine, Kyiv, 35. (in Ukrainian).
10. Rokityansky, I. I., Ingerov, A. I. (1999). Electromagnetic studies of the Carpathian electrical conductivity anomaly. Geophysical Jornal, 21(4), 59-70. (in Russian).
11. Semenov, V. Yu., Кulik, S.N., Logviniv, I.М. (1996). Еstimation of the geological structure. Dopovidi NAN Ukrayiny, (12), 134-137.
12. Tretyak, K. R., Maksymchuk, V. Yu., Kutas R. I., at al. (2015). Suchasna heodynamika i heofizychni polya Karpat ta sumizhnykh terytoriy [Modern geodynamics and geophysical fields of the Carpathians and the adjacent territories]. Lviv, Lviv Polytechnic Publishing House. 420. (in Ukrainian).
13. Varentsov, Iv. M. (2007). Array of simultaneous EM soundings: design, data processing and analysis. Electromagnetic sounding of the Earth's interior. Methods in geochemistry and geophysics, (40), 259-273.
14. Wiese, H. (1963). Geomagnetische Tiefentellurik. Teil III: Die geomagnetischen Variationen in Mittel- und Sudost-Eoropa als Indikator der Streichrichtund grossraumiger elektrischer Untergrundstrukturen. Geofisica pura et applicata, (56), 101-114.
15. Zhdanov, M. S., Golubev, N. G., Varentsov, I. M., Abramova, L. M., Shneer, V. S., Berdichevsky, M. N., Zhdanova, O. N., Gordienko, V. V., Bilinsky, A. I., Kulik, S. N. (1986). 2D model fitting of a geomagnetic anomaly in the Soviet Carpathians. Annales Geophysicae, 4(3), 335-342.