The article presents the results of experimental and methodological work on the use of magnetotelluric sounding in the area of ​​the Russian Progress Station (Princess Elizabeth Land, East Antarctica). The research was accomplished by a field team from the Saint Petersburg Mining University in the course of the 71st Russian Antarctic Expedition (2025-2026) and is a continuation of the comprehensive geological and geophysical studies of East Antarctica. The main focus is on the practical application of the method in high polar latitudes. Issues related to ensuring the operability of the equipment, fieldwork logistics, and the influence of physiographic conditions on measurements are considered. The study of the geological structure of the Antarctic continent is complicated by the occurrence of a thick ice sheet which ensures the leading role of geophysical methods in solving this problem. The article presents the results of practical application of the Russian Nord electrical prospecting hardware-software measurement system and the Canadian MTU-5A together with preamplifiers designed to compensate for a high grounding contact resistance. The experimental and methodological survey line is laid across the Amery lineament, a large linear magnetic anomaly extending sublatitudinally for over 500 km. A comprehensive interpretation of magnetotelluric data and the anomalous magnetic field was accomplished. A resistivity section was constructed using a two-dimensional inversion, and a direct problem for the magnetic field was solved. As a result, a model is proposed for the structure of the Proterozoic suture zone, the rocks of which create a positive anomaly in the magnetic field. In the resistivity section, the anomalies with increased conductivity at depths below 10 km correspond to this structure. The obtained data create new opportunities for studying the deep structure and geodynamics of the East Antarctica.

The article analyzes the amplitude spectra of audio magnetotelluric sounding (AMTs) data. Particular attention is focused on the frequency range from 1 to 5 kHz, which is called dead band. We analyzed the data of base stations used in the fieldwork during the summer and autumn seasons in 2013, 2014, and 2017. The area of work is located in the Chukotka Autonomous Area beyond the Arctic Circle. Previous researchers noted that a reliable signal in the dead band can only be obtained at nighttime. The authors of the article found that in Chukotka region in the daytime against the minimum signal within the dead band there is a local maximum at a frequency of 2.4 kHz. When registering a field for more than 3 hours during daytime, in most cases, it is possible to restore the frequencies of 2.2 and 2.6 kHz. These frequencies are reliable benchmarks, allowing in some cases to restore the AMT curve using the correlation between amplitude and phase. We have proposed ways to improve data quality in the dead band when measured during the daytime.