2025-12-14
P. Salyuk, D. Stepanov, O. Kochetov, A. Ostrovskiy, I. Stepochkin, N. Lipinskaya, M. Gorbov, A. Bulanov, D. Shvoev, A. Lazaryuk, A. Pivovarov, A. Samchenko, N. Shmykov, E. Ivanchenko
In May–June 2024, an automatic mobile tethered Winchi profiler equipped with a YSI EXO2 Multiparameter Sonde was used to conduct fine-scale measurements of thermohaline stratification and bio-geo-optical parameters in Vityaz Bay (Peter the Great Bay, the Sea of Japan) for the first time. The data quality was improved by correcting the depth profiles of sea water temperature and absolute salinity to account for the response time of the temperature sensor, resulting in a reduction of the root-mean-square-error (RMSE) relative to reference profiles by factors of 5 and 6, respectively (final RMSE = 0.13◦C and 0.1 g/kg). The analysis revealed the presence of quasi-inertial (~18 hours) and diurnal (~24 hours) oscillations, as well as significant shifts in near-surface layer properties, through analysis of collocated thermohaline and bio-geo-optical data.
2025-12-14
D. Peskov, A. Zharkov, D. Kalinin
The East European Platform is one of the most extensively studied regions of Russia in terms of geological exploration. However, certain areas remain relatively underexplored from a geological and geophysical perspective. One such region in the European part of Russia is the Mezen syneclise and the adjacent shelf of the White Sea. This area is characterized by complex and poorly studied geological structures. No hydrocarbon inflows have been obtained from the sedimentary cover deposits of the Mezen syneclise. The oil and gas potential of the region can only be inferred from hydrocarbon shows and elevated hydrocarbon concentrations detected in the underground waters of the Riphean and Vendian formations during drilling. Based on a conceptual geological model and an evolutionary-genetic analysis of the region’s development, an assessment of the specific resource density of the Precambrian section of the sedimentary cover was conducted. A key factor that influenced the region’s hydrocarbon potential was the Vendian collision of the East European Craton with the Pechora Plate. The prospects for discovering oil and gas accumulations are associated with the platform slopes of the most subsided structures, including the Safonovsky, East Safonovsky, and Leshukonsky depressions. The primary exploration targets are structural-lithological hydrocarbon traps located along these slopes, which have been minimally affected by tectonic transformations and may have preserved their hydrocarbon potential.
2025-12-14
M. Ramazanov, L. Lobkovsky, N. Bulgakova, S. Gadzhimagomedova
A mathematical model has been formulated to describe the degradation of saline permafrost containing ice, gas hydrate accumulations, and free gas, as a result of climate warming and the influence of heat flow from below, considering the effects of osmosis. The degradation rates of hydrate-bearing permafrost from above and below, along with the corresponding rates of methane release into the surrounding permeable fractured-porous medium and gas migration channels or faults, have been studied. To investigate degradation from above, several temperature values at the upper boundary of the frozen layer were considered, including both positive and negative values in degrees Celsius. This allowed for the separate assessment of the contributions of heat and salinity to the degradation rates, as well as to evaluate the role of osmotic forces. To investigate degradation from below, several values of heat flow caused by the geothermal gradient were considered. As an application of the model, the results of calculations for the degradation rates of the frozen hydrate-bearing layer, following the onset of ocean transgression on the Arctic shelf approximately 10 thousand years ago, are presented.
2025-12-14
A. Golynskiy, D. Golynsky, A. Kiselev, A. Sakharov, M. Egorov, N. Gonzhurov
Interpretation of modern aeromagnetic and radar data, primarily from Russian surveys in East Antarctica between 88°–102°E, has resulted in a tectonic map of Precambrian provinces, including two protocratonic domains and two orogens of different ages. The crust of the Charcot Province is presumably composed of Mesoarchean tonalite-gneisses of Cape Charcot (3003 ± 8 Ma), which underwent metamorphism at ~2890 Ma and a zircon-forming episode at ~550 Ma. The West Mawson protocraton province is identified based on magnetic data and is represented by terranes that may have accreted to the western edge of the East Mawson craton in the Mesoproterozoic. The Wilkes Orogen correlates with metamorphic and intrusive rocks of the Bunger Hills, Highjump Archipelago, Obruchev Hills, and exposures in the lower reaches of the Denman Glacier, mostly associated with positive magnetic anomalies forming an elongated, segmented magnetic belt. The Rayner Orogen has a heterogeneous geological structure and can be subdivided into several tectonic zones with specific lithological compositions and slightly different geological histories. All previously proposed fault locations (sutures) between Indo-Antarctica and Australo-Antarctica are not reflected in either modern aeromagnetic data or bedrock topography. Most likely, it is located along the boundary between the Charcot craton and the Wilkes Orogen and corresponds to the Northcliffe Glacier. ADMAP-2 data allow tracing its continuation towards the southern Prince Charles Mountains and/or the subglacial Gamburtsev Mountains.
2025-12-14
A. Vorobev, A. Soloviev, G. Vorob'eva
The development and implementation of new correlation-statistical models for the operational assessment of technospheric risks arising from the impact of space weather on power electric systems operating within the boundaries of the auroral oval is currently an urgent research problem with a pronounced applied nature. Such models demonstrate the highest practical significance in polar subregions with a low density of coverage by reliable and credible sources of geomagnetic data (Taimyr Peninsula, Gydan Peninsula, northern regions of Yakutia, etc.), i.e., in fact, the overwhelming territory of the Arctic zone of the Russian Federation (AZRF). Thus, the paper is concerned with a new approach, which is proposed to the non-hardware assessment of the level of geoinduced currents (GIC) in the power electric systems of the AZRF, which is based on correlation-statistical modeling of the GIC level according to the observation of auroras as an accessible natural indicator of space weather state. Using the example of the Vykhodnoy substation of the Northern Transit main power grid, it is shown that when registering auroras in the north, at the zenith, and in the south, the probable (averaged over 30 min) GIC levels are ~0.08 A, ~0.23 A, and ~0.68 A, respectively. At the same time, the probability of exceeding the average half-hour GIC levels of 2 A (in the case of auroras in the north, at the zenith, and in the south) are ~6%, ~10%, and ~15%, respectively.
2025-12-14
A. V. Kileso, V. A. Gritsenko
An analysis of small-scale gradient characteristics of the underwater coastal slope surface near the shallow sandy shores of the Kaliningrad Peninsula provided qualitative and quantitative estimates of the horizontal gradients of the bottom slope, curvature, and the steepest descent trajectories. Sections of the slope with morphological features such as erosional gullies and cross-slope-oriented channels were identified, creating favorable conditions for suspended sediment transport during severe storms in the form of along-slope suspension currents. Based on the criterion proposed in this study, a classification of the coastal zone near the Kaliningrad Peninsula was carried out according to the degree of negative impact of bottom slope morphological features in the context of potential shoreline erosion under storm conditions.
2025-12-14
D. A. Harutyunyan, V. V. Zhmur
This study examines the behavior of a circular ellipsoidal ocean vortex in an external baroclinic flow with vertical shear. It is established that the vortex lifetime under fixed initial parameter conditions strongly depends on the external shear parameter. Depending on the vortex lifetime, the representative point in the parameter space may reside in one of three zones: (1) the survival zone, where the vortex lifetime tends to infinity, (2) the finite lifetime zone, and (3) the stretching zone, where the vortex lifetime approaches zero. At a certain shear velocity value, the infinite vortex lifetime becomes finite. This shear value, corresponding to the boundary between zones (1) and (2), is characterized as critical. The critical shear, in turn, depends on the initial geometric parameters of the vortex core. The work also investigates the vortex energy evolution. It is shown that during vortex stretching by the baroclinic flow, the total mechanical energy decreases both for the core and the entire vortex. Furthermore, the quasi-geostrophic balance remains valid for all three behavioral regimes.