Geofizicheskiy Zhurnal

Integrated geospatial assessment of geodynamic hazard along the pipelines in the Ukrainian Carpathians

Olga Titarenko — 2026-04-18

This study addresses the problem of assessing the impact of hazardous geological processes on the functioning of pipelines. The study area lies within the Ukrainian Carpathians, a region of high geodynamic activity and frequent landslides. The relevance of the research is determined by the increasing frequency and intensity of exogenous processes in mountainous areas, the ongoing effects of climate change, and the necessity to enhance the reliability and safety of critical infrastructure. The aim of the study is to identify areas of increased geodynamic hazard along the pipelines in the Ukrainian Carpathians through a comprehensive assessment of multi-factor remote sensing data.

The proposed methodology integrates morphometric, climatic, and infrastructure-related components using remote sensing data and GIS-based spatial analysis. A set of topographic indices derived from the SRTM digital elevation model was calculated to characterize the potential susceptibility of the territory to landslide development and erosion processes. These indices reflect slope steepness, flow accumulation, surface runoff energy, and terrain ruggedness, which are key factors controlling slope instability in mountainous environments. In addition, land surface temperature, derived from Landsat imagery, and average annual precipitation were incorporated to account for climatic influences on slope processes.

All factors were integrated within a unified geoinformation environment to map the distribution of potential geodynamic hazards along the pipeline. The resulting map represents a raster-based hazard index that reflects the combined influence of natural and anthropogenic factors. The results make it possible to delineate high-risk zones. They can be used to improve monitoring systems, maintenance planning, and preventive risk management strategies in mountainous regions, particularly within the Ukrainian Carpathians.

To assess the reliability of the proposed model, the obtained hazard levels were compared with the spatial distribution of documented landslides within the study area, based on regional geological records and open geospatial datasets. The analysis revealed a clear spatial correspondence between high-hazard zones and recorded landslide occurrences, indicating a statistically meaningful correlation and confirming the adequacy and practical applicability of the proposed geospatial assessment approach.

Geopolariton tomography of the internal structure of earth: a passive method for analyzing seismogenic zones

Yuriy Bogdanov — 2026-04-18

This study presents geopolariton tomography, a passive geophysical method for investigating the dynamic states of the lithosphere based on event statistics of natural electromagnetic responses. Unlike traditional electromagnetic and seismic approaches, geopolariton tomography does not rely on frequency or amplitude analysis, but employs an event index λ that reflects the intensity of transitions between coupled electromagnetic-mechanical states of the geosphere.

The study introduces geopolariton states as coupled electromagnetic-mechanical responses in which energy is redistributed between electromagnetic and elastic-relaxation modes. Within this framework, the classical skin-depth limitation is addressed at the level of system description: the observed effects are interpreted as stress-controlled modulation and cascading reorganization of coupled states localized primarily within fault-controlled structures rather than as direct electromagnetic penetration from depth.

Using the Bishkek-Tokmak profile (Northern Tien Shan) as a case study, the method reveals volumetric stress clusters and seismic quiescence zones interpreted as dynamically active regimes of elastic energy accumulation. Earthquake hypocentres are shown to form stable parametric ellipsoids, with the most energetic events concentrated near their boundaries, consistent with phase-transition-like processes between energy accumulation and release.

The physical meaning of the event index λ and its nonlinear relationship with the stress-strain state of the lithosphere are discussed. Geopolariton tomography is positioned as a tool for diagnosing pre-critical states and monitoring fault-zone dynamics rather than for deterministic earthquake prediction.

Validation of global elevation models using ICESat-2 LiDAR data for floodplain modeling in the Ukrainian Carpathians

V.V. Nikoriak — 2026-04-18

Accurate topographic data underpin hydrological and floodplain modeling in mountainous environments where steep gradients and dense forest cover amplify vertical errors in global Digital Elevation Models (DEMs). This study performs a comprehensive validation of freely available DEMs — SRTM v3, NASADEM, ASTER GDEM v2, ALOS AW3D30, Copernicus GLO-30, FABDEM, and TanDEM-X — against high-precision Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) LiDAR altimetry within the Ukrainian Carpathians. To ensure geodetic consistency, all DEMs and ICESat-2 observations were vertically transformed to the European Vertical Reference System (EVRS) using the high-resolution European Gravimetric Quasi-Geoid EGG2015 prior to analysis.

Elevation residuals were quantified using both classical (Mean Error, Root Mean Square Error) and robust (Normalized Median Absolute Deviation) statistical metrics, combined with terrain-stratified analysis based on slope, land cover, and hydrological position derived from the Height Above Nearest Drainage (HAND) model. The results demonstrate that DEM errors are strongly controlled by terrain steepness and vegetation cover, with non-linear error amplification observed in slopes exceeding 12° and in forested areas.

Among the tested datasets, FABDEM demonstrates the lowest mean error (≈1.5 m) and the highest stability across all slope classes. In contrast SRTM and NASADEM systematically overestimate elevations in forested terrain due to canopy effects. Copernicus GLO-30 and ALOS AW3D30 exhibit moderate accuracy but degraded performance beyond 15° slopes. ASTER GDEM displayed the largest variability and extreme errors, particularly in complex terrain.

Hydrological analysis revealed that DEM-related uncertainties propagate directly into floodplain modeling outputs. Within the critical HAND 0—6 m zone, vertical errors (5—10 m) were comparable to or exceeded typical flood depths, resulting in substantial discrepancies in inundation extent, channel geometry, and hydraulic parameters.

The study further demonstrates that compliance with international accuracy standards (INSPIRE, FEMA, LAWA) is generally limited to low-relief terrain, whereas most global DEMs fail to meet requirements in mountainous regions. These findings highlight the necessity of using DTM-type datasets or LiDAR-derived elevation models for regulatory flood-risk assessments.

To support reproducible and scalable analysis, the study introduces the GeoHydroAI framework — an integrated geospatial analytical environment combining ICESat-2 processing via SlideRule, DEM differencing using xDEM, terrain analysis with WhiteboxTools, and high-performance spatial querying with DuckDB.

This approach enables automated validation, terrain-stratified error analysis, and interactive exploration of DEM uncertainty across geomorphological and hydrological gradients. The proposed framework establishes a reproducible standard for DEM evaluation and provides a data-driven foundation for flood-risk assessment and hydrological modeling in data-scarce mountainous regions. Furthermore, the integration of geodetic referencing (EVRS/EGG2015), satellite altimetry (ICESat-2), and geomorphological analysis establishes a physically consistent framework for terrain representation in hydrological applications. This work positions DEM validation as a core component of GeoAI-driven environmental modeling, bridging geodesy, remote sensing, and hydraulic simulation within a unified analytical paradigm.

Application of machine learning methods to study the relationships between seismicity and geodynamic features of the Dnister Hydropower Complex

Ivan Brusak — 2026-04-18

This study investigates the seismicity and recent geodynamic features of the Dnister Hydropower Complex in Ukraine, emphasizing the application of machine learning methods to analyze their interrelationships. The complex, situated in a seismically active transitional zone, is influenced by natural tectonic processes and anthropogenic activities, including the operations of the Dnister Hydroelectric Power Plant and active water level changes at the Dnister Reservoir. Data from digital seismic stations of the Carpathian Seismological Network, permanent Global Navigation Satellite System stations of GeoTerrace and SystemNet networks, as well as reservoir water level records of Dnister Reservoir, were collected and analyzed together. Machine learning algorithms, including Random Forest, Isolation Forest, and DBSCAN clustering, were employed to identify patterns and correlations between crustal deformations, water level fluctuations, and seismic events. Results reveal a significant association between water level changes — both short-term and long-term — and earthquake occurrences, suggesting that hydrological variations impact seismic activity. Geodynamic analysis indicates heterogeneous deformation patterns, with increased velocities in seismically active southwestern regions. Global Navigation Satellite System data shows velocities increasing by about 2 mm/year near the Dnister Hydropower Complex. Seismicity near the Dnister Hydropower Complex from 2012 to 2023 was characterized by peak earthquake years of 2014—2016 and 2022, each with over 100 events. The total seismic energy released increased from lg(ΣE)=7.5 in 2012 to 10 in 2016, then steadily declined to 7 by 2023. The findings enhance understanding of the mechanisms of induced seismicity related to reservoir operations and provide valuable insights for risk assessment and mitigation strategies in hydroelectric regions. This integrated approach demonstrates the effectiveness of machine learning in deciphering complex geodynamic and seismic interactions in tectonically sensitive environments.

A new approach to measuring geomagnetic field declination

A.M. Andreev — 2026-04-18

It is essential to measure the components of Earth’s magnetism, including its configuration, spatial distribution, short-term and long-term variations, and its relationship with other phenomena originating on the Sun, in the atmosphere, or within the Earth. Modern instruments enable high-precision measurements of the components of the geomagnetic field. However, in certain situations — such as emergencies in marine navigation — a conventional compass may remain indispensable.

The authors propose a device whose design rivals the simplicity of the classical compass. This instrument eliminates the structural drawbacks of dry friction between the elements of a conventional compass by using a fluid support, which removes dry friction within the device, thereby significantly increasing its sensitivity and enabling the measurement of magnetic declination and its variations.

The results of experimental investigations of the device are presented. It can measure the geomagnetic field’s declination and its temporal changes. Its simple construction and high sensitivity compared to a standard compass make it a promising tool for numerous practical applications. The device is capable of detecting even minute variations (on the order of arc minutes) in magnetic declination caused by short-term disturbances over the course of a day (diurnal variation). The instrument can function as a portable autonomous device for research in meteorology, geophysics, and navigation.

Complex application of the reflected and refracted wave methods in the study of the Kurinsky depression

Hafiz Shakarov — 2026-04-18

The article presents a comprehensive study of the geological and deep structure of the Kurinsky depression. The research is based on regional seismic profiles acquired using a specially designed observation system that ensures the simultaneous recording of both reflected and refracted waves along the same profile. Field surveys were carried out using the 2D common depth point method with vibratory sources and refracted-wave observations employing explosive sources to track deep geological boundaries. Analysis of the kinematic and dynamic parameters of the wavefield has shown that the most reliable information on geological structure, elastic heterogeneities, and tectonic features is primarily contained in the reflected and refracted wavefields. Combining reflected and refracted wave data, especially in the deeper zones where reflection data alone is limited, allows for the creation of higher-quality dynamic depth sections. The combination allowed for the separation of seismic signals from noise, improved the mapping of Mesozoic structures, and enabled reliable correlation of seismic horizons at depths greater than 8—10 km.

The results indicate that the joint application of seismic reflection and refraction methods significantly enhances the completeness, accuracy, and reliability of seismic data interpretation. The analysis shows that, when selecting an appropriate observation system during seismic investigations, it is possible to record different types of waves along the same profile. These waves correspond to different geological boundaries and depths and are registered at different time intervals. The proposed comprehensive methodology enables the development of a more reliable seismogeological model of deep structures and is recommended for use in other regions with complex geology, as well as in hydrocarbon exploration. The results indicate that investigations of this type should be carried out in other regions using a denser network of seismic profiles.

Groundwater exploration in the Garachay river basin using vertical electrical sounding method

Avaz Salamov — 2026-04-18

Since Azerbaijan is located primarily in a semi-arid zone, water shortages have always been a problem. Beginning from the second half of the 20th century, rapid population expansion and economic growth have further increased water demand. The geophysical survey in the Garachay river basin using the Vertical Electrical Sounding aimed to provide high-quality fresh groundwater for the nearby settlements. The geological section was dissected in detail. It consists of 8—10 layers of alternating boulder-pebble rocks with thin clay layers. The geological section of the study area is plicatively differentiated. Each identified aquifer is underlain by an impermeable layer, in which rocks are mostly composed of clay. The thickness of the alluvial deposits changes between 1—12 m and their specific electrical resistivity were determined to be 50—450 Ohm‧m. The resulting map shows an increase in the thickness of alluvial deposits from the northwest to the southeast. The main physical parameters, such as natural moisture content, density, the density of rocks under water, and filtration coefficient have also been determined. In the right-bank part of the study area, the sediment filtration coefficient varies between 1—3 m/day,
while in the left-bank part, it ranges from 6 to 12 m/day. The constructed 3D models clearly demonstrate how the electrical resistivity of the rocks that make up the geological section decreases from the surface down. This is presumably due to an increase in natural rock moisture with depth or an increase in clay particles content in the deeper layers. All of this suggests that the study area is promising for fresh groundwater exploration.

Estimation of gas volume based on four wells in the G field, East Sengkang Basin, South Sulawesi Indonesia

O. Dewanto — 2026-04-18

Research in Sulawesi is still very limited due to the complex tectonic conditions. Due to the lack of drilling, subsurface formation data is very limited, so further research is needed. Against this background, this study attempts to estimate the gas volume in the G field, based on four oil and gas wells in the East Sengkang Basin, South Sulawesi. Fortunately, the wells are located close together, allowing for accurate volume estimation. The four wells are GI-1, GI-2, GI-3, and GI-4. The objectives of this study are: first, to determine the depth of the gas reservoir zone (qualitative-quantitative); second, to determine the total gas volume in the reservoir zone. Gas volume estimation uses well logging methods to obtain subsurface data, specifically hydrocarbon potential. Bulk reservoir volume is a representation of the volume of a 3D model that is influenced by reservoir thickness. Determining the bulk reservoir volume is used to estimate the volume of gas hydrocarbons. 3D modeling is an important method in the oil and gas industry to understand subsurface characteristics. Therefore, the findings are expected to provide important insights for energy resource development and serve as a reference for the oil and gas industry in evaluating gas hydrocarbon potential. The results showed a water saturation below 30 % with a resistivity above 60 Ohm·m, indicating the presence of gas. Furthermore, the total gas volume was 4.46⋅108 m3, indicating significant potential in the prospective reservoir zone. The gas potential in the entire Sengkang Basin field block reached 226.5⋅108 m3, while the calculated gas volume in the study area resulted in 4.46⋅108 m3. Based on these calculations, the gas volume in the study area is quite realistic.

Assessment of the potential of the BMP388 microbarometric MEMS sensor as a low-cost sensor for dynamic atmospheric pressure monitoring and detection of rapid disturbances

Igor Kosyak — 2026-04-18

The article analyzes the operation of the BMP388 microbarometric MEMS sensor, which records pressure and temperature measurements and provides accurate altitude tracking. The study assesses the potential of this sensor as a low-cost alternative to traditional high-precision expensive devices used for dynamic geophysical monitoring and detection of low-frequency (infrasonic) atmospheric pressure fluctuations. The relevance of the work is determined by the need to create low-cost, scalable networks for registering fast atmospheric disturbances, including infrasound, which is generated by a wide range of natural and anthropogenic sources. To verify the capabilities of the sensor, a series of studies were conducted by changing its internal settings (oversampling and IIR filtering), which are key factors for achieving the optimal signal-to-noise ratio in the dynamic range. The studies encompassed both long-term monitoring of natural barographic changes over a 25-hour data recording, which captured the characteristic dynamics of pressure variations (a double anomaly correlating with the passage of a thunderstorm front) and an analysis of the response to pulse pressure impact and the determination of microbarometric resolution. The main methodological conclusion is based on a comparison of configurations with activated and deactivated internal IIR filtering. Complete deactivation of the IIR filter led to the dominance of high-frequency noise in the spectrum and a significant decrease in signal-to-noise ratio, even when the useful low-frequency signal remains registered. Thus, active IIR filtering is a critical prerequisite for achieving high data quality in dynamic mode. The results substantiate the suitability of the BMP388 as a low-cost sensor for operational monitoring of atmospheric disturbances and demonstrate its potential for integration into more complex geophysical measurement systems.