Home – Home – Jornals – Journal of Mining Sciences 2025 number 5

The article considers socio-economic factors of population migration in municipalities on the example of the Sverdlovsk Oblast. The study is based on the concentration analysis of the spatial distribution of migration flows using a combination of autocorrelation and regression modeling methods. The purpose of the study is to identify the significant factors affecting migration flows of population, taking into account the spatial relationship between municipalities. The main objectives of the analysis include the study and identification of statistically significant indicators affecting the resettlement of people. Migration flows have a noticeable impact on the demographic structure of the population, as well as on the state of local and regional labor markets. During the study period from 2010 to 2022, uneven distribution and increased concentration of migrants in large municipalities increased the outflow of population from sparsely populated areas. The use of a set of methods - assessment of migration flows concentration, spatial autocorrelation and spatial regression analysis - allows us to fully determine the zones of concentration of migration flows and identify factors affecting resettlement within the Sverdlovsk Oblast with the further purpose of using the study to adjust and plan the development of the territory.

Since 2023, according to the decree of the Government of the Russian Federation, Berezovsky and Beloyarsky municipal districts of Khanty-Mansi Autonomous Okrug-Yugra are the districts of the Arctic Zone of the Russian Federation. These are the two districts where indigenous small-numbered peoples of the region - Khanty and Mansi - predominantly live. The goal of the article is to analyze the situation with indigenous minorities at municipal labor market and to identify peculiarities of their embeddedness. Research hypothesis: In Arctic regions of the Khanty-Mansi Autonomous Okrug-Yugra, representatives of Khanty and Mansi demonstrate a lower level of employment rate comparing to the rest of the region’s population, which indicates insufficient integration at municipal labor market and a lower level of embeddeness associated with lack of vocational education (65.2% of Khanty and Mansi) and insufficient qualification. The methodology of the research is associated with a comparison of data from open sources. It also includes recommendations for improving the situation at the labor market in the Arctic regions of Khanty-Mansi Autonomous Okrug-Yugra, for example, recommendations for of special educational programs, development of traditional crafts, etc. The analysis has shown the correspondence of labor resources with geographic location of enterprises. Khanty and Mansi live in three municipal districts which are considered to be the least balanced in terms of labor market - Berezovsky, Beloyarsky, Kondinsky. The analyzed data for 2023 indicates the aggravation of the situation at municipal labor market for Khanty and Mansi and indicates an acute need for new measures to be taken.

This article is devoted to the analysis of the effectiveness of state support measures for the socio-economic development of Russian regions, based on the assessments by civil servants in the constituent entities of the Russian Federation. The subject of the study is the perception by regional authorities of various instruments of federal support. The purpose of the work is to identify the problems that arise in the implementation of these measures and to develop proposals for their improvement. The methodological basis of the study was the analysis and generalization of the results of a survey conducted by the RANEPA Center for Regional Policy in cooperation with the Commission of the State Council of the Russian Federation on Economics and Finance in September-October 2024. The survey covered civil servants of various subjects of the Russian Federation. The results of the analysis showed significant differences in estimates of the effectiveness of support measures depending on the group of regions. Some problem areas were identified, in particular, the supervision of deputy prime ministers in the federal districts received low marks. The assessment of the release of funds within the framework of debt restructuring on budget loans turned out to be ambiguous. The tools of the “infrastructure menu" and preferential territories, in general, received positive reviews. The findings of the study contribute to understanding the attitude of regional authorities towards federal support and identify areas for improving its effectiveness. The results obtained can be used to improve the mechanisms of state support for regional development, optimize the allocation of resources and increase the effectiveness of the implementation of federal programs. They may be of interest to government authorities, researchers of regional economics and experts in the field of management.

The article examines the most important modern environmental challenges and the risks and threats caused by them, taking into account both national and regional and international aspects of the growing importance of the environmental agenda. An analysis of the cause-and-effect relationships between the presence of hazards contained in a particular challenge and the real damage that can be caused to the natural environment, living conditions and human health has been carried out. Possible ways to prevent potential risks and threats to the environmental and economic development of the country are proposed. Among the identified challenges, emphasis is placed on challenges that contain risks and threats caused by factors of both a global nature and those associated with the peculiarities of the formation of environmental and economic policy in Russia and its regions. These include tightening environmental requirements for products on foreign markets, taking into account the technologies used for their production and the resulting carbon footprint; close intertwining of environmental issues with technological and economic problems; changes in environmental regulations within the country in connection with external sanctions imposed on it, and others. The statement about the existential nature of the considered environmental challenges is substantiated. It is concluded that the existing institutional environment in Russia, which also determines the effectiveness of state environmental policy, requires transformation, subject to active state support in the field of innovation, technological sovereignization of the economy based on domestic best available technologies and other measures based on socio-economic and environmental motivation, based primarily on the principles of economic efficiency and environmental justice. The proposals made for improving the mechanism of environmental and economic policy can be useful in developing instruments for regulating the environmental sphere at all levels of management.

The article discusses new opportunities and risks on the southern border of the taiga, where swamps are being naturally drained due to climate warming. Highlighting the dangers that arise in these conditions, the author puts the high risk of fires first in connection with the need to take emergency measures. The paper notes that drainage of swamps has stopped all over the world and work on their restoration is beginning. The difficulties of assessing the likelihood of fires, as well as developing technologies for marsh restoration (re-wetting), are discussed. Along with new dangers, the author describes new opportunities that appear for the economy in connection with the processes occurring on the southern border of the taiga. Among the new possibilities, the article discusses new directions for the use of peat and a more active involvement of wild plants from the swamp environment in economic circulation. Particular attention is paid to the problem of increasing soil fertility in areas cleared of swamps and taiga. Options for changing crop rotations and introducing new agricultural crops into them are also considered.

In this paper we consider nonlinear fractional differential equations involving the new Caputo-Fabrizio derivative of order γ ∈]1, 2[. We convert the fractional problem to an equivalent nonlinear Volterra integro-differential equation of the second kind, then we investigate the existence and uniqueness of its solution under certain given conditions by using the Schauder fixed point theorem. Finally, we numerically solve the proposed fractional problem by applying the Nyström method, and we provide some suitable examples to support our study.

Conjugate gradient methods represent a powerful class of optimization algorithms known for their efficiency and versatility. In this research, we delve into the optimization of the Generalized Descent Symmetrical Hestenes-Stiefel (GDSHS) algorithm by refining the parameter c, a critical factor in its performance. We employ both analytical and numerical methodologies to estimate the optimal range for c. Through comprehensive numerical experiments, we investigate the impact of different values of c on the algorithm's convergence behavior and computational efficiency. Comparative analyses are conducted between GDSHS variants with varying c values and established conjugate gradient methods such as Fletcher-Reeves (FR) and Polak-Ribière-Polyak (PRP⁺). Our findings underscore the significance of setting c =1, which significantly enhances the GDSHS algorithm's convergence properties and computational performance, positioning it as a competitive choice among state-of-the-art optimization techniques.

A numerical solution by the finite element method of a homogeneous Dirichlet boundary value problem for an elliptic equation is examined (using a Poisson equation as an example) in a two-dimensional convex polygonal domain Ω with a singular right-hand side given by the Dirac delta function. A theorem on the existence and uniqueness of a generalized solution in the fractional Sobolev space H^s(Ω), 1/2 < s < 1, is proved. An approach to discrete analysis of the problem using the finite element method is proposed and investigated. The results of numerical experiments for a model problem, obtained using the FreeFem++ software, are presented. They confirm the error estimate of the difference between the discrete and exact solutions derived in the paper.

An emerging field of study is the application of fractional calculus to iteratively solve nonlinear equations. Recently, several Newton-type techniques have been proposed that make use of the notion of fractional order derivatives. However, the existence of at least first order derivative is essentially required for the convergence of these methods. On the contrary, we propose a new secant-type method which is inherently derivative-free, although its construction is based on the idea of conformable fractional derivative of order α ∈ (0,1]. The primary objective for the development is to analyze how fractional derivatives have an effect of enlarging the convergence domain. In this regard, the proposed scheme is examined for its convergence characteristics and dynamical features for different values of α in the specified range. Furthermore, the efficacy of the method is demonstrated through solving various applied nonlinear problems including the fractional order Burgers' equation.

In this paper, we will give a new Crank-Nicolson mixed covolume method for parabolic optimal control problems. The state and co-state variables are approximated by the lowest order Raviart-Thomas element and the control variable is approximated by piecewise constant function, while Crank-Nicolson scheme is ultilized for temporal discretization. We derive the priori error estimates for the control variable, the state and the co-state variables.

The aim of this paper is to derive efficient numerical algorithms for the numerical solution of nonstiff ordinary differential equations by applying the Richardson extrapolation technique to a class of explicit two-derivative Runge-Kutta methods. Theoretical results illustrate that the application of this technique has considerable impact on the accuracy and stability properties of the underlying numerical methods. The achieved improvements of the proposed algorithms are also confirmed by the results of some numerical experiments.

The stress-strain research of rock mass is carried out, with verification by observations over underground openings at the Starobin and Petrikov deposits of potassium salt. The qualitative and quantitative indicators of the limit state zones in the vicinity of mine openings at moderate and great depths were compared using an integrated criterion. The formulas are proposed for determining sizes of limit state zones at great depths, with regard to geological structure of the test deposits. The numerical modeling algorithm of formation of rock blocks in the vicinity of underground openings on the basis of introduction of special block elements as systems of elastic and viscoelastic links is discussed. The research findings are applicable in stability assessment of mine openings in planning mining operations, and in selection of mine support and protection methods.

The article presents the ground surface deformation monitoring data for a 40 years-long period. The space and time parameters of geodynamic movements are revealed from the analysis of long-term observation over ground movements. The ground movement data base is created for the classification, modeling and estimation of ground movements, and for the analytical definition of patterns in big data arrays. The statistical and wavelet analyses of rates of change in vertical displacements of ground surface are performed. The ground surface zoning is carried out at the Sarany chromite deposits and in the adjacent areas with a town and industrial facilities. The results are useful for the detection of unknown parameters of geodynamic processes on ground surface, and for the prevention of accidents connected with instability of capital facilities during underground mining.

The estimation procedure of a displacement zone at a mined-out void filled with cemented paste backfill in mining of kimberlite deposits of ALROSA is described. The applicability of numerical stress-strain modeling and established normative standards is demonstrated. The deficiency of the current methods and norms in delimitation of hazardous displacement zones is identified. The proposed solutions conform with the actual conditions of the Internatsionalny and Aikhal Kimberlite Mines. Localization of a hazardous deformation zone nearby a mined-out area is demonstrated as a case-study of underground mining with cemented paste backfill in the Mir-Gluboky Mine. The displacement zone parameters at the Mir-Gluboky Mine are calculated.

The article addresses seismic activity induced and triggered by iron ore mining in Gornaya Shoria. In 2024 in the populated areas of Sheregesh and Tashtagol, perceptible earthquakes with local magnitudes 4.5 and 4.6 took place, respectively. A partial synchronization effect in seismic activity was revealed in the area of three mines, namely, Tashtagol, Sheregesh and Kaz, with simultaneous amplification of seismicity over a period from 2012 and to the present day. Seismic activity is spasmodic, with periodic attenuation both in terms of energy and number of seismic events, and with the subsequent recommencement. The energy of seismic activation events correlates with the mining rate and steadily rises as the latter grows.

The authors have developed the method of adapting blast designs and patterns to structurally complex mineral deposits on the basis of synthesis of theory of zonal rock fracture and theory of blast impulse. This article describes the sequence of practical adjustment of blast designs and patterns with regard to geological conditions. The method includes monitoring of rock mass, analysis of data, selection of techniques and their efficiency evaluation using an integral criterion embracing safety of blasting, quality of fragmentation and economic indicators. The authors propose classification of the techniques and their combinations, capable of reduction of seismic impact, flyrock and expenditure. Particular attention is given to the blast impulse peak pressure and duration control. The results enable adapting blast designs and patterns to nonuniform rock mass, and enhancing safety and efficiency of mining operations. The research prospects are connected with artificial intelligence technologies and digital data bases for forecasting blasting impact.

Coarse oversize fragments generated by blasting complicate loading and haulage of rocks, and this leads to the decreased productivity of labor and to the increased cost of mining. This article analyzes specific energy of roller-bit drilling as a drillability criterion as a case of the Koktaszhal deposit in Kazakhstan. Two electric drill rigs DML-1200 were additionally equipped with energy consumption recording facilities. The correlations between the powder factor, explosive fracture energy and ultimate compression strength of rocks, and between the average fragment and specific drilling energy are determined. For the blast design practice in open pit mining, it is substantiated to pass from mechanical specific energy of drilling to specific energy of explosive fracture and, further, to prediction of an average fragment of blasted rock. The experimental blasting operations at the Koktaszhal open pit mine show positive results which open prospects for the further research.

The authors discuss a variant of shrinkage stoping in mining steeply-dipping ore bodies of limited thickness. In the context of the majority of operating mines in Russia, numerical stress-strain modeling of gravitational stress state of an ore-rock mass is performed. The stress patterns in structural elements of the discussed geotechnology are determined as function of thickness and occurrence of the ore body, and subject to the technology implementation. It is found that rock mass quality greatly influences stability of different-purpose mine openings and ore pillars. The safe mining system parameters are determined and standardized for the typical geological and geomechanical conditions of the test deposits.

The geomechanical substantiation is provided for the technology of sublevel caving in mining close-spaced ore bodies with dirt parting of a varying thickness. The parametric model of sublevel caving includes the case of maximum advance of stoping front on sublevels. The computational patterns of maximum principal and shear stresses, as well as their concentration and relaxation in the main constituents of the mining system are obtained. The rock mass areas around various exposures, including preparatory and development openings, which are most susceptible to failure in case of complex tectonics, are identified. The analysis of different depths of driving fringe drifts and a decline in hanging wall of an ore body in depth of mining proves consistency of the adopted engineering solutions and safety of mining in varying geological and geotechnical conditions for the whole period of operation. The order and sequence of extraction of close-spaced ore bodies are validated to ensure caving of enclosing rocks toward mined-out void at the proper ground control. The parameters of underhand sublevel stoping, such that ensure safety and efficiency of mineral mining, are determined.

The authors obtained an analytical time law of freeze pipe temperature which ensures the constant thickness of a frozen wall at the stage of passive freezing. The time law is established using the equation of balance of heat flows at the phase interface. The correctness of the mathematical expression is proved by numerical modeling of freezing of a siltstone layer typical of conditions of shaft sinking in potash mines. The results are applicable in planning energy-efficient operating regimes of freeze pipes during passive freezing.

Scale modeling is essential in studying underground mine fires since large-scale experimentation is impossible because of unsafety while numerical modeling has limited accuracy and features high computational input. This article addresses an understudied issue of selection and substantiation of similarity criteria for the analysis of mine fires. The review of the current methods available for scale modeling of heat convection of air under high temperature differences on the basis of investigations of fires in buildings and tunnels displays their insufficient conformity with mine conditions owing to difference in geometry and in air flow behavior. The dimensional analysis reveals that similarity in laboratory modeling is achievable through observance of equality of the dimensionless Richardson, Euler and Froude numbers. The authors describe an emergency scenario, with switching-off of fans, when the only defining criterion is the Grashof number. The proposed approach makes it possible to design low-temperature lab-scale experiments to model air flow along mine openings during fire.

The analysis of organic collector adhesion to the surface of diamonds and kimberlite minerals in an aqueous medium determined the main characteristics of physical and chemical properties of the mineral-water-collector interfaces and the collector adhesion patterns at variation of the type and concentration of different class control reagents. It is found that control reagents reduce differently adhesion of an apolar collector to diamonds and floatable kimberlite minerals. This allows expecting a positive effect of the increased selective attachment of the collector to minerals being separated. The criterion of the collector attachment selectivity is proposed to be the ratio of adhesion energies of an apolar collector at diamond, talk and phlogopite. The test results demonstrated a tight correlation between the coating of diamond and kimberlite surfaces with an organic collector and the collector adhesion to diamond and phlogopite. The applicability of the proposed criterion for the selection of the control reagents for selectivity of attachment of apolar collectors in weakly mineralized recycled water is substantiated. The visiometric process analysis of attachment of a luminophore-bearing apolar collector at minerals of a diamond-kimberlite mix shows that the use of sodium hexametaphosphate and oxyethylene diphosphonic acid reduces amount of an organic collector on the surface of kimberlite and enhances stability of the collector adsorption on the surface of diamonds.

The influence of changeability of dry magnetic separation feed characteristics on the separation process efficiency is considered at the fixed operation modes of equipment is examined as a case-study of the Olenegorsk deposit ore. It is found that the major effect is exerted by the content of total iron: its increase in the feed is independent of the maximum linear size in the size grade and of the size modulus, and is accompanied with Fe_tot content growth in the magnetic fraction. The results of dry magnetic separation of a narrow particle size range prove that for - 80 + 2 mm, the correlation of Fe_tot content of the magnetic fraction (at В = 0.16 T) has a high approximation coefficient of 0.9461, which is reflective of a weak contribution of the feed size to separation efficiency. Regarding influence exerted on separation performance by the size modulus, it is found that the absence of ore pretreatment by sifting ensures reduction in loss of Fe_tot with the nonmagnetic fraction in 70% of cases.

Hydrofluoric acid (HF) proved to be the most efficient reagent for the flotation separation of feldspar minerals from quartz. This research aimed to improve the quality of Wadi Zirib feldspar ore for industrial applications. Furthermore, the effect of HF on the feldspar separation process was studied. Laboratory scale flotation experiments were conducted with quaternary ammonium salt solution as a cationic collector for feldspar minerals. HF was used as a surface modifier for the activation of feldspar minerals and quartz depression, as well. The optimum concentration of HF varied between 1800-2000 g/ton. A 1800 g/ton HF dosage gave a feldspar assay of 89.81% with 44.20% recovery. A 2000 g/ton HF dosage gave a feldspar assay of 85.05% with a 67.78% recovery. Overall, a suitable quality feldspar concentrate was obtained with a mass recovery of 52.11%, having a composition of 69.04% SiO₂, K₂O & Na₂O combined more than 11%, 17.34% Al₂O₃ and about 0.4% Fe₂O₃. This product could fulfill the requirements of glass, porcelain, ceramic, vitreous tiles and semi-vitreous tiles industries.

The aim of this paper is to present an approach to predict the performance of tunnel boring machines (TBM) in Iranian water conveyance tunneling projects using an artificial neural network (ANN) approach. With this respect, a database, including field data and machine parameters, was primarily compiled from the excavation of top five Iranian water conveyance tunnels. The database was then analyzed through ANN to yield an optimum predictive model for the rate of penetration. The results show that there is a close equation between actual (measured) data and predicted data with correlation coefficient of 0.94, and the values of coefficient of determination and root mean square error obtained in this research are equal to 0.90 and 1.2, respectively.

The authors analyzed water quality in manmade water bodies at the used and operating tungsten, molybdenum and complex ore mines in eastern and southwestern Transbaikal. The chemical analysis of water used atomic absorption spectrometry and inductively coupled plasma mass spectrometry. The standardized cumulative pollution index is calculated. It is found that the level of the environmental hazard of the test water bodies is abnormally high, which points at the environmental emergency and ecological catastrophe. The greatest threat to surface and underground water is made by the manmade water bodies at the Pervomaiskoe, Sherlova Gora, Bukuka and Bom-Gorkhon deposits. The recreational utilization of such water by people is unhealthy and inadmissible.

The applicability of InSAR technique in stress-strain assessment and alteration prediction in rock mass is illustrated as a case-study of the Upper Kama Salt Deposit. The object of research is Berezniki Mine-1 flooded in 2006 after an accidental freshwater inrush. Because of high solubility of salt rocks, velocity of ground subsidence is yet very high within the mine field. Subsidence monitoring is carried out here using benchmark surveying along existing profile lines and TerraSAR-X-base radar survey with a period of 11 days. The InSAR data were interpreted using 3D mathematical modeling of deformation process in undermined rock mass. The computational model displayed a whole set of geological and geotechnical conditions, and a group of factors associated with the freshwater inrush. The numerical calculations used the semi-analytical finite element method. Within the framework of the developed modification of the method for variable-module deformations, InSAR data were a part of the parametric content of the geomechanical model determining deformation of undermined rock mass in time.

The article presents the laboratory studies on cyclic treatment of fine-pore and banded bituminous coal with liquid nitrogen. Permeability of coal cores was determined in the mode of nonstationary flow, and porosity was assessed using the methods of nuclear magnetic resonance and optical microscopy. The procedures and design solutions used in the experiments are described. The change in permeability of coal along and across its banding is examined in the conditions of hydrostatic compression. It is found that permeability of test coal grows by one-two orders of magnitude along its banding and by two-three orders of magnitude across the banding. Anisotropy of permeability decreases. This effect intensifies with the increasing hydrostatic compression and water saturation of coal. It is shown that the effect of the liquid nitrogen treatment is mostly associated with different-scale crack growth in coal at a minor change in open porosity.

The authors have theoretically substantiated and experimentally tested the method of determining permeability of discontinuities as function of stresses in rock masses and reservoirs of quasi-regular layered deformation structure when fluid flows across the strike of the discontinuities. A linear model produces an analytical solution of a problem on stationary fluid flow in media with discontinuities, which allows finding the permeability kJ of the latter by the recorded flow rate. The tests are carried out using samples of sandstone blocks and a dependence is obtained for the interblock space opening h and the normal stress s. A lab-scale testing plant is proposed for the permeability tests with the coincident directions of compression and fluid flow. As a result of the experiments on gas flow in block samples subjected to normal loading, an empirical dependence is found for the specific discontinuity permeability kJ/h and the stress s, which can be approximated by a two-parameter fractional rational function.

Fine particles, when flowing with fluids in the Earth’s crust, can settle on surfaces of pores and fractures, and form colloid barriers which drastically reduce permeability of jointed media. When seismic waves travel in fault zones, which have greatly different stiffness as compared with enclosing rocks, Biot slow-wave diffusion originates, which can cause destruction of the colloid barriers, growth of permeability, redistribution of pore pressure and change in the stress-strain condition of a fault. This article describes the studies into conditions when regular seismic impacts induced by massive blasting can lead to a drastic change in the permeability in the fault zones.

Three calculation models are developed for estimating the cross size of a main crack formed by a blasthole in perimeter blasting: a numerical model for calculating the equilibrium shapes and sizes of a flat crack in 2D elasticity, and two analytical models for estimating the cross size of a flat crack in two-dimensional and axially symmetric problems. The models are used to calculate the sizes of main cracks formed in granite in blasting of ammonite charges of different density. The comparison of the 3D numerical calculations with the 2D and axially symmetric modeling results has allowed finding the conditions when the analytical modeling produces such precision that makes the analytical models applicable in design of perimeter blast patterns.

The article presents the results of the physical modeling of hydraulic fracturing in coarse cement cubes subjected to triaxial loading. The laboratory-scale plant, hardware and software tools, as well as the methods and engineering solutions applied during the experiments are described. The pressures and the trajectories of fractures which intersect the earlier created crack, including propped fractures and fractures filled with an isolating polymer, are investigated. The possibility to control hydraulic fracturing by deformation of a close-spaced hollow cavity which models an underground opening is demonstrated experimentally.

The article reports the experimental data on the effect of sodium laureth sulfate and neonol AF 9-12 on the fracture energy of dolomite at the Internatsionalnaya pipe and limestone at the Mokhsogollokh open pit at temperatures in a range of + 20 … - 30 °C. In the positive temperature range, the fracture energy of dolomite treated with surfactants, lowers by 28% on the average. Under negative temperatures, an increase is observed in the fracture energy of dolomite samples saturated with surfactant solutions. At the temperatures below - 10 °С, the fracture energy of dolomite exceeds its fracture energy at the positive temperatures by 2.3-3.1 times. The indicators of fracture of dolomite samples saturated with surfactants totally agree with the fracture indicators of water-saturated samples. The fracture energy of limestone treated with surfactant solutions decreases by 5-10% under positive temperatures and increases by 8-15% under negative temperatures as compared with the fracture energy of air-dried samples.

Rockburst disaster is a kind of typical dynamic disaster phenomenon. In this work, the risk level of the rockburst disaster was predicted based on the convolutional neural networks and long short-term memory (CNN-LSTM), and particle swarm optimization and general regression neural network (PSO-GRNN) models. A CNN-LSTM deep learning model based on rockburst chaotic time series was proposed to predict the characteristic variables of rockburst state, with a method to quantitatively distinguish and predict the risk level of the rockburst disaster in the future, and thus the dynamic prediction of the rockburst activity was realized. As an example, the microseismic monitoring variables (i.e., indexes of the daily cumulative microseismic energies and daily maximum microseismic energy, angular frequency and concave-convex radius) and electromagnetic radiation signals (i.e., indexes of the daily average amplitude and daily maximum pulse) were used to predict the rockburst. The CNN-LSTM and PSO-GRNN models were confirmed to be the most suitable to predict the risk level of the rockburst. This work provides an important basis for timely mastering the future state of rockburst activities.

Climate changes in permafrost regions lead to noticeable alteration of the environmental conditions, including, in particular, an increase in permafrost temperature and depth of seasonal thaw and an activation of exogenous cryogenic processes. This paper presents the results of monitoring the active layer thickness and vertical surface displacements at the Circumpolar Active Layer Monitoring (CALM) site Lavrentiya located in the area of the “Eastern Chukotka Coastal Plains” research station. Under conditions of the increased summer heat supply over the period of 2004-2024, the rate of ground surface subsidence varied from 1.4 to 3.5 cm/yr, while changes in the active layer thickness (ALT) were from -3.2 to +1.6 cm/yr. The ground surface subsidence took place due to the isotropic thawing of the ice-rich transient layer of the soil-permafrost complex without the formation of thermokarst landforms. Thus, against the background of relatively stable variations in the ALT, a gradual unidirectional subsidence of the surface caused by the progressive thawing of the transient and intermediate layers was observed. The results highlight a significant underestimation of the rates of permafrost table deepening obtained by the traditional mechanical probing method.

The results of experimental studies of the influence of the initial freezing conditions and heating-cooling cycles of a finely dispersed model soil (kaolinite clay in a fully water-saturated state with the moisture content of 0.43-0.51) on its water filtration properties in the frozen state are presented. The filtration capacity of frozen kaolinite clay depends not only on its temperature but also on the freezing conditions. Graphs of the water permeability coefficient of the frozen soil versus temperature in the range of -0.05…-0.3 °C have been obtained for various soil freezing conditions. These graphs demonstrate the significant influence of freezing conditions on the filtration properties of frozen soil. Experimental research in this area is important for predicting the behavior of frozen heavy-textured soils near the initial freezing temperature, which is especially relevant in a changing climate.

Landscape-hydrological and hydrogeological changes have been studied in a second-order creek valley with water recharge taliks formed along two linear faults and an isometric depression closing the lower fault. A hypothesis about the tectonic origin of these changes is advanced based on the analysis of aerospace materials, in situ observations, and reference data. At least until 1965, there was no runoff in the valley downstream of the depression, and the maximum water infiltration rate exceeded 4 m³/s. Surface water infiltration, together with the deposition of sediment load, took place mainly in the depression. Subsequently, both processes virtually stopped there because of the rise of the bottom of the depression relative to the valley thalweg, and a fully developed channel was shaped downstream. Surface water infiltration has decreased by more than an order of magnitude and is observed now mainly in the area of linear faults. In the depression, it occurs sporadically at its margin, where a tectonic ditch is perpendicular to the creek channel. The ongoing tectonic activity may cause high intensity of water intake, up to the spontaneous discharge of the channel flow. In the observed case, such a discharge flow developed in the channel in the direction opposite to the slope of the creek thalweg. Such spontaneous phenomena cannot be explained within the framework of modern concepts about the minimum size of mobile tectonic blocks and attest to the need for their revision.

A design and technological solution to modify the soil temperature regime and maintain the upper boundary of permafrost in the roadbed at the required depth was developed. The main causes of road failure in permafrost regions were identified. The effect of water accumulated at the base of the roadbed on the temporal variation of the inclined permafrost table depending on the road slope was studied using numerical modeling. Numerical modeling was used to select the key geometric parameters of the design and technological solution controlling the temperature variation of the foundation soils. Regression equations describing the temporal variation of the slope of permafrost table in the roadbed were obtained using the mathematical planning of the experiment.

Icing formation represents a hazardous engineering-geological process that adversely affects infrastructure facilities. To predict icing development and suggest adequate control measures, it is necessary to identify the location of the icing water source and plan the placement of water intake wells. Geophysical methods help solve these tasks. The objective of this study was to investigate the structure of the groundwater discharge zone feeding a hydrogeogenic icing to plan anti-icing measures. The investigations employed ground-penetrating radar (GPR) equipped with an OKO-3 system and a 250 MHz antenna, capacitive-coupled resistivity measurements using VEGA instrument at 16.5 kHz frequency, and electrical resistivity tomography with induced polarization measurements using Skala-64k15 system. GPR data revealed that the seasonal freezing depth within the icing mound reaches 1.8-2.7 m. Signs of groundwater discharge were identified as local anomalies with reduced seasonal freezing depth down to 1.3 m. The study established that the icing mound forms over a seasonal frost heave mound containing an ice core, while the bedrock base shows evidence of a fault zone. Electrical resistivity tomography surveys and 3D modeling of resistivity and normalized chargeability distributions to a depth of 100 m enabled the identification and delineation of branching vertical channels of ascending groundwater filtration. These channels form a group source feeding the icing.

On August 8, 2025, Igor Vladimirovich Klimovsky, a senior researcher at the Melnikov Permafrost Institute, Candidate of Geographical Sciences, Honored Worker of the Economy of the Republic of Sakha (Yakutia), Veteran of Labor, and Honored Veteran of the Siberian Branch of the Russian Academy of Sciences, passed away at the age of 90. He will be remembered as a remarkable permafrost researcher committed to geocryological science, a tireless explorer, and an excellent field worker.