During the expeditionary research of 2023-2024 in the conditions of thick Antarctic ice sheet, the medium- and low-frequency ground penetrating radars (GPR) OKO-3 with a 150 MHz antenna and Triton-M with an extendable 25-50-100 MHz antenna (LOGIS LLC, Russia) improved and adapted for glacier investigations were tested for the first time. An example of the ice sheet study in the Schirmacher Oasis area showed that the OKO-3 GPR allows obtaining detailed information on the internal structure of the ice sheet to depths of about 200 m and successfully solving glacial stratigraphy issues. The Triton-M GPR has proven itself well for mapping the roof of underlying rocks to depths of 250-300 m. The article presents new data on the glacier structure in the Novo Runway area, as well as information on the glacier thickness and the subglacial rock base topography near the Schirmacher Oasis (Novolazarevskaya and Maitri stations). Typical structures of the glacier strata in this area are gently sloping layers and steep folds that replace them, complicated by crevasses. The subglacial topography to the south of the oasis is quite gentle. Individual uplifts and depressions do not exceed 30 m. The interface between the ice and the rock base was recorded over a distance of 4.5 km to the south of the oasis. In the east, about a kilometre from the last rock outcrop, the oasis is limited by a sharp depression in the bed. New data opens up the possibility of constructing the ice sheet models, studying its dynamics and evolution, and finding patterns in the crevasse formation.

In autumn 2023, comprehensive geophysical surveys were conducted in the experimental section of the Shestakovka River basin (Central Yakutia) to identify structural features of the near-surface part of the geological section, in particular permafrost rocks and talik zones. The work objectives included ground penetrating radar (GPR) studies and electrical resistivity survey. Drilling and well temperature logging data were used in the interpretation. The work is relevant due to the importance of studying the processes occurring in the cryolithic zone due to global climate change, and the novelty lies in clarifying the structure of the study area. The average permittivity of rocks across the section on the right and left banks of the river is 15.5 and 6.9, respectively. The differences are due to moisture saturation and the degree of soil freezing. The depth of the talik base on the right bank of the river is from 2 to 14 m with an average value of 6.1 m. On the left bank of the river, it varies from 3 to 7.1 m with an average value of 4.2 m. According to electrical exploration, the medium is a four-layer section. The upper layer about 2 m thick is the most heterogeneous in electrical resistivity and corresponds to seasonally frozen soils. The base of the underlying talik on the geoelectric section is traced at a depth of 4 to 7 m, which is consistent with drilling and GPR data. The third high-resistivity layer corresponds to permafrost rocks. The electrical resistivity in them increases by an order of magnitude compared to the talik zone and is about 2000 Ohm·m against the background of 100-270 Ohm·m. The underlying lower layer is characterized by a decrease in electrical resistivity to 220 Ohm·m, which may be associated with a change in the lithological composition or with the groundwater circulation.

The results of complex geophysical and geochemical investigations on testing area, which is developed now for student field search and exploration trainings in the north part of Lake Ladoga region, are presented. Model objects corresponding to different geological situations (zones of tectonic faults, metamorphic carbonaceous-siliceous rocks and ore skarns) have been chosen for student field trainings. Manifestation of these objects in geophysical and geochemical fields is concidered. Here we show a number of signs and criterions of ore skarns and graphitic deep faults (ore canals).

The technique and results of electrical explorations using electrical tomography procedure in permafrost on the Taimyr Peninsula are presented. The zones of permafrost, «sluggish» frozen zones and thawed soils (talik) are revealed and identified based on the values of resistivity. The authors suggest the method of interpretation with the help of the electrical resistivity spatial gradient for the identification of sediments in the cross-section. It was found that the areas with high-gradient of resistivity correspond to the frozen loam, and the areas of low gradient coincide with the sand layers in the permafrost.