Russian Journal of Earth Sciences

As a rule, it is known from a priori data that the studied field anomalies are caused by geological structures located at a certain depth below the day surface. Separation of anomalies of the observed potential field by depth and their connection with deep objects can form the basis of interpretation schemes for modeling problems. The classical method of field separation includes spectral filtering with subsequent analytical continuation of the separated anomalies. We propose an original method of height-based transformations of potential fields based on solving the inverse problem of analytical continuation of harmonic functions from a plane to the “inner” half-space. This problem is reduced to solving the Fredholm integral equation of the first kind for the Poisson integral, which can be used to represent a harmonic function in the “outer” half-space by its boundary values on the plane. The parallel algorithm for solving the integral equation is implemented on graphics accelerators using the NVidia CUDA and AMD ROCm libraries in the application software. The results of the method application are shown on the example of separation of the vertical component of the gravity field in the Bouguer reduction for the Sarginskaya area (Urals, Russia). For this territory, a detailed 3D density model was created by solving the linear inverse problem of gravimetry.

The most important element of the structure of hydrocarbon resources is their distribution by accumulations of different sizes. The formalism of this direction is developed in detail. Estimates of the resource structure of the largest oil and gas provinces of Russia are carried out. However, the lack of a substantiated theoretical model for the formation of the distribution of accumulations by size gives rise to a number of problems, including practical ones. This concerns the forecast of the number of small accumulations and hydrocarbon resources concentrated in them in well-studied oil and gas systems, the forecast of distribution for poorly studied systems, and the identification of the relationship between distribution parameters and the geological characteristics of the oil and gas system. The explanation of some empirically established regularities, in particular, the stable nature of the value of the λ ~ 2 distribution parameter, is of independent theoretical interest. The paper presents the current state of this complex of problems and some possible directions for their solution.

Based on the analysis of the anomaly magnetic field for the Amur Plate and adjacent territories, a Curie Point Depth (CPD) map has been constructed, which we identify with the isotherm 578°C — the temperature of the Curie point of magnetite. Within the Amur plate, the CPD values range from 13.4 to 38.0 km. Three large areas are clearly visible on the map: 1) NE-trending zone with CPD values of 25–20 km — Yellow Sea-Korean Peninsula-Sea of Japan; 2) ENE-trending central zone with CPD values of 30–38 km. Large depth values are due to the presence of the late Paleozoic and Mesozoic sedimentary basins of Erlyan, Songliao and Sredneamursky; 3) ENE-trending central zone with CPD values of 30-38 km. Large depth values are due to the presence of the late Paleozoic and Mesozoic sedimentary basins of Erlyan, Songliao and Sredneamursky. The fourth area of decrease in CPD values spatially coincides with volcanic structures of Pliocene-Pleistocene age in the area of the Toko Stanovik. Comparison of the generated CPD map with the Amur plate boundaries determined mainly from seismic data shows that the surface boundaries of the plate coincide mainly with the zones of the largest gradients of the 578°C isotherm distribution in depth.

Information from the Unified State Fund of Data on the State of the Environment and its Pollution (USFD), which consolidates large amounts of data from hydrometeorological observations and pollution monitoring, is one of the key factors affecting the life of modern world society and the stable economic development of every state on the planet Earth. This effect is due to the presence of particularly dangerous hydrometeorological phenomena and adverse weather conditions that can cause social and economic damage. In this regard, the tasks of collecting, accounting, long-term storage and timely provision of such information to consumers of various sectors of economic activity for use in decision-making remain relevant. This article discusses the key aspects of the information technology of the USFD, which is formed as a result of the activities of the Federal Service of Russia for Hydrometeorology and Pollution Monitoring (Roshydromet). As a result of the work, a description of the technological process of maintaining USFD, statistical data on the demand and use of USFD information and a new documentary information search system solving the problem of accounting and long-term storage of USFD information resources are presented. The system was developed using modern information technologies, international standards for describing information resources and taking into account the experience of foreign organizations engaged in activities similar to Roshydromet. The direction of further development of digital technologies for operational public service with information products created on the basis of verified USFD information resources is also outlined.

The article presents an approach to creating a detailed regional digital geological model for the territory of Western Siberia. The non-standard nature of such tasks is noted, and a conclusion is made about the need to develop specialized software for these purposes. The variational grid mapping method as a tool for constructing digital structural models and property fields is considered. The object-hierarchical approach is proposed as a method of data space managing, algorithmization and automation of calculations. The “GST Agent” technology as an instrument of expanding the functionality of the software if proposed. The digital model of the region includes a structural framework consisting of more than 30 stratigraphic boundaries, as well as detailed submodels for the most studied areas. The approach ensures the possibility of automated recalculation of the model and full compliance of the modeling results with all the original data.

Fluids have a significant impact on seismic processes in the lithosphere and the earth's crust. They can form systems of mantle-crust migrants that rise in a solid plastic medium due to fluid-fracturing. When migrants are formed, the energy accumulated earlier in the parent chambers under the strength barriers is released. The accumulating energy includes the potential energy of lithostatic pressure and the energy of deformation of the strength barrier . The released energy includes the energy of cavity formation in the strength layer and the energy of fluid ascent into the cavity . According to the condition + − − > 0, the remaining mechanical energy is the cause of such seismic events as rock bursts, unstable zones of low longitudinal wave velocities and seismic “nails”.

In less than six years, three devastating earthquakes with magnitude exceeding 8.0 have occurred over the Chilean subduction zone. These events were quite well recorded by permanent GNSS stations. We used finite element modeling for a spherically symmetric layered Earth and machine learning methods to investigate the geodynamic processes preceding and accompanying the Chilean earthquake sequence. We find that preseismic coupling before all events is strongly correlated with the coseismic slip distribution, while afterslip primarily located around the coseismic slip patches. We also found that large geologic structures of the oceanic plate have a decisive influence on the development of geodynamic processes in the rupture zones of large Chilean earthquakes.

Understanding the growth dynamics of water droplets is crucial for accurate modelling of cloud formation and climate processes. This paper delves into the theoretical aspects of condensational growth of tiny water droplets in humid environments, such as warm clouds. The effect of droplet size on growth is examined using a semi-analytical model based on established kinetic principles, including the effects of diffusion and the medium discontinuity. While it was previously understood that smaller sizes are followed by slower growth rates, the refined model predicts that submicron droplets should grow even more slowly than anticipated. The model is consistent with previous conclusions and encompasses the growth of larger droplets as a limiting case. This model is expected to be applicable across a broad range of settings, from near-freezing conditions in clouds to elevated temperatures in technical applications involving hot steam-droplet mixtures, where Stefan flows are significant.

The purpose of this work is to determine the main regularities of icing distribution in the Selenga middle mountains. The objectives of the study included mapping of icings using Landsat imagery and geoinformation analysis of their spatial differentiation. The geoinformation analysis of the distribution of icings in the Selenga mid-mountain depending on various environmental factors (tectonics, relief, permafrost, meteorological indicators) revealed the main regularities of their formation. The relation of the glaciers to different categories according to the main classification features was determined. Icings of the Selenga mid-mountain are divided into 4 size classes (medium, large, very large and giant), 2 main genetic types are identified according to the prevailing sources of supply (groundwater and spring icings), the number of slope and valley icings is determined. The role of relief and snow cover influence on the distribution of icings in the territory was assessed. It has been established that in the current climatic conditions in the Selenga middle mountains 7.7 thousand icings are formed, most of which (70%) belong to groundwater icings. The maximum number of glaciers is observed in areas with a transitional type of permafrost distribution, while valley glaciers prevail in mountainous areas at altitudes from 850 to 1000 m. They are formed along watercourses in intermountain hollows and in the spurs of mountain ranges.

The method developed by the authors for detection of Forbush effects in cosmic ray variations based on ground data of neutron monitors is presented. The method is based on the synthesis of the classical theory of risks with nonlinear approximating schemes in wavelet bases. The basis of the method are the rules composed by the authors. Numerical realization of the developed rules makes it possible to obtain a solution close to optimal without pre-training in near real-time mode. On the example of periods of extreme magnetic storms in 2024, method results confirming its efficiency are illustrated. General anomalous dynamics of the cosmic ray flux is distinguished. Anomalous changes, preceding the beginnings of the events under analysis, were discovered. The observed correlation with the changes of interplanetary environment parameters indicates the reliability of the obrained results.

The experience of studying the consequences of strong earthquakes indicates that intensity and type of seismic effects are determined by local features of the geological environment, which can change over time under the influence of natural and man-made factors. The results of longterm systematic experimental studies on the study of changes in seismic conditions over time in the soil complexes of the Imereti lowland and the site of the Balakovo NPP are presented. This made it possible to carry out long-term forecasting of changes in seismic conditions during economic development of territories.

During the period of maximum solar activity, extreme space weather events increasingly affect technical means and systems. The article considers the ground-based heliogeophysical observation platform, as well as on-board heliogeophysical hardware complexes (GGAK), which conduct operational monitoring of space weather from space crafts.

This paper outlines the main milestones in the evolution of the Geophysical Center of the Russian Academy of Sciences (GC RAS) over its 70-year history. It covers the period from the establishment of the Interdepartmental Committee for the Preparation and Conducting the International Geophysical Year under the Presidium of the USSR Academy of Sciences to the formation of a progressive academic institute. Particular attention is paid to the individuals who contributed to the development of the scientific potential of the institute. We discuss the modern directions of fundamental research of the GC RAS and emphasize those, which are highly demanded in solving crucial applied problems.