Earth’s Cryosphere, 2022, Vol. XXVI, No. 2, p. 42-50.

SHALLOW-DEPTH TRANSIENT ELECTROMAGNETIC SOUNDINGS FOR IDENTIFICATION OF GAS-HYDRATE ACCUMULATIONS IN THE CRYOLITHOZONE OF THE NORTHERN REGIONS OF WESTERN SIBERIA

E.V. Murzina^1,3, A.V. Pospeev^1,2, I.V. Buddo^1–3 , M.V. Sharlov³, I.K. Seminskiy^1,3, N.V. Misyurkeeva^1,3, I.A. Shelohov^1,3

1 Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, Lermontova str. 128, Irkutsk, 664033 Russia
2 Irkutsk National Research Technical University, Lermontova str. 83, Irkutsk, 664074 Russia
3 SIGMA-GEO LLC, Zvezdinskaya str. 6, Irkutsk, 664039 Russia; mkv@sigma-geo.ru

The territory of the north of Western Siberia is known as one of the promising regions of the Russian Arctic in terms of reserves of alternative fuel sources, in particular, gas hydrates. According to the results of interpretation of the data of 3D areal near-field transient electromagnetic sounding (NTES) in the permafrost zone, performed in Nadym district of the Yamalo-Nenets Autonomous okrug at depths of 100–220 m, geoelectric anomalies of increased electrical resistivity values were revealed, accompanied by the manifestation of double induced polarization. The authors associate the mentioned anomalies with the possible accumulations of gas hydrates in the permafrost thickness. To justify the applicability of the sounding method by the formation of the field in the near zone in a shallow modification for mapping subpermafrost geoelectric anomalies in the permafrost zone, a description of a mathematical experiment is presented. The experiment is based on empirical electromagnetic data. As a result of mathematical modeling, it is shown that the use of electromagnetic soundings by the formation of the field in the near zone makes it possible to estimate the conductivity and polarizability of the upper part of the section of the study area and to identify anomalies in the permafrost zone, which are probably associated with hydrate-bearing deposits.

Frozen ground, permafrost zone, gas hydrate, near-field transient electromagnetic sounding (NTES), double-induced polarization, electrical resistivity