Human activities such as mineral extraction in the Kryvyi Rih region, have significantly altered the geological environment, affecting soil stability and creating additional risks for buildings, infrastructure, and urban facilities. A comparable process of environmental destabilization occurred much earlier in the Kyiv Pechersk Lavra area, where historical architectural structures and cultural monuments were also influenced by changes in the geological environment. Although these processes occurred in different centuries and were driven by distinct historical and economic factors, their consequences exhibit similar patterns. In both regions, cracks of varying severity, localized ground subsidence, and gradual displacement of buildings toward zones containing underground cavities-both natural and man-made-have been documented. This study employs high-precision laser inclinometers of a Ukrainian design which detect small angular deformations of the ground surface and allow the analysis of factors contributing to slope instability and soil movement in areas with pronounced surface gradients and complex morphology. Two identical laser inclinometers were installed for experimental monitoring: one in Kyiv and one in Kryvyi Rih. One instrument is certified by the State Enterprise & laquo;UKRMETRT-ESTSTANDARD & raquo; and meets modern national standards of accuracy, providing reliable data on soil displacement. Results indicate that lunar-solar tidal forces may influence the stability of shallow soil layers, particularly in regions with significant surface gradients and subsurface voids. These findings demonstrate the considerable potential of laser inclinometer monitoring for investigating geodynamic processes, assessing deformation risks, predicting hazardous ground movements, and improving urban safety in areas with complex surface morphology and underground cavities.
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 degrees and in forested areas. Among the tested datasets, FABDEM demonstrates the lowest mean error (approximate to 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 degrees 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.
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 & centerdot;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.
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.
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.
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 rightbank 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.
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.
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 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(Sigma E)=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.
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.
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 lambda 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 lambda 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.
The article concerns the endogenous regime of recent activation in SW Ukraine and adjacent territories of Moldova and Romania. Starting from a chronology of research on the topic, it proceeds to outline the current state of knowledge. There are different views of how the activation manifests and why the deep processes are so difficult to grasp. In the region, it is possible to determine the age and nature of geological phenomena identifiable with elements of recent activation. They are different for the platform part and the Carpathians. In the first case, young vertical movements with anomalously high velocities occurred during the Pliocene-Pleistocene. In the second case, a unique concentration of mantle-depth earthquakes (the Vrancea zone) forms a vertical focal structure. Accordingly, the research is divided into two parts. The heat flow on the platform part of the region and the margin of the Scythian plate has a background level of 50-55 mW/m(2) and two anomalies of up to 80-85 mW/m(2). The anomalies' intensities and shapes correspond to the calculated parameters of the deep process of recent activation. The differences are due to the crustal intrusions of partially molten mantle rocks, approximately 2-5 million years old, beneath the anomalies. Their thermal models agree with the distribution of seismic wave velocities with sufficient accuracy. It is possible to diagnose even the individual episodes of intrusion of deep superheated material under the crust. Thermal models explain the significant surface uplift during activation, the formation of faults, and the seismicity. The high-conductivity objects also map well unto heat flow anomalies and lie at depths corresponding to intervals of significant superheating and partial melting.
This article is the first attempt to establish a connection between magnetic heterogeneities in the crystalline crust in the Teisseyre-Tornquist Line region of the SW edge of the East European Craton and heterogeneities in the mantle. A 3D magnetic model of the crystalline crust was created using near-surface anomalous magnetic fields, velocity and structural sections from seismic profiles. The sources are attributed to two levels: local sources to the entire thickness of the upper crust, and deep ones to the middle and lower crust. Magnetization is assumed to be homogeneous, equilibrium, and constant to the depth of the Moho discontinuity or until the Curie temperature of magnetite is reached. This model parameterization led to the estimation of the minimum possible values of source magnetization. The total effect of crustal sources was matched to the observed field by trial and error with an error of no more than 30 nT. The relationship between crustal magnetic heterogeneities and mantle structure is based on the use of compiled diagrams of the main features of the crystalline crust, of the heterogeneity of the subcrustal mantle, and the transition layer from the upper to the middle mantle. The main feature of the 3D magnetic model is the presence of deep magnetic bodies accompanying Teisseyre-Tornquist Line, the S & ouml;rgenfrey-Tornquist Zone and the Thor-Tornquist Suture. The strip of magnetic bodies from NE is limited by the lineament L subparallel Teisseyre-Tornquist Line, which we have identified based on the magnetic field structure. It correlates with the Caledonian deformation front in Fennoscandia and the Rava-Ru'ska fault in Sarmatia. This allows us to link magnetic sources with the activation of the Teisseyre-Tornquist Line system and mafic intrusions. The magmatic genesis of these magnetic sources is also evidenced by their location above the overthrust of the subcrustal mantle of the East European Craton onto the mantle of the West European Platform. The overthrust was established based on seismotomography data. It correlates with the underthrust of the lower crust of the East European Craton under the crust of the West European Platform. It is assumed that these structures are connected with their synchronous movement from the NE to the SW, the formation of a stretchingzone, and the intrusions. The stretching regime along the Teisseyre-Tornquist Line may also be caused by SW subduction, which is confirmed by the identified high-speed inclined layers (slabs).The magmatic origin of magnetic sources does not exclude the formation of 'secondary' magnetic minerals due to the penetration of deep fluids into the crystalline crust. This process is facilitated by the increased permeability of the lithosphere, the 'blurring' of the main geodynamic boundary, and the disturbance inthe transition layerstructure of the upper mantle. The nature of deep magnetic sources associated with Teisseyre-Tornquist Line can thus be explained by both primary magnetic minerals of mafic rocks and secondary minerals brought up from the depths.
The publication highlights the main stages of development, the current state, and the key scientific achievements of the S. Subbotin Institute of Geophysics of National Academy of Sciences of Ukraine on the occasion of its 65th anniversary. It is shown that, despite difficult socio-political conditions and the challenges of wartime, the Institute maintains its scientific potential and continues active fundamental and applied research in priority areas of modern geophysics. We present a generalized overview of the staff composition, organizational structure, and scientific divisions of the Institute and outline the activities of leading scientific schools as well as new interdisciplinary research areas. Particular attention is paid to cooperation with government authorities, industrial organizations, and international partners, as well as participation in departmental, competitive, contractual, and grant-funded projects. The most significant results of the past five years are summarized. In particular, these include studies of the deep structure of the Earth's crust and mantle of Ukraine and adjacent regions, geodynamics, seismic hazard assessment, geothermics, magnetic and gravity fields, paleomagnetism, and development of new methods of geophysical research and instrumentation. The applied significance of these results is demonstrated for mineral resource prospecting, assessment of seismic and environmental risks, development of the oil and gas sector, and national security. The material summarizes the contribution of the S. Subbotin Institute of Geophysics of National Academy of Sciences of Ukraine to the development of national and global geophysical science and outlines prospects for further research.
We examined the geological structure of the crust and mantle within the transition zone between the Sarmatia and Fennoscandia miniplates. The zone encompasses the central and southern parts of the Svecofennian orogen and the northwestern segment of the Ukrainian Shield. It is extended south-eastward to include several northeast-striking fault zones of the Ukrainian Shield (from the Horyn to the Teteriv fault zones, inclusive). The interpretation of the crustal structure is based on recent publications by Swedish, Polish, Estonian, Lithuanian, and Ukrainian scientists. The mantle to depths of 850-2500 km was investigated using a three-dimensional velocity model of Eurasia, developed by V.S. Geyko at the S. Subbotin Institute of Geophysics of the NAS of Ukraine based on seismic tomography using the Taylor approximation to the eikonal equation and the wave equation. It is showed that the Sarmatia-Fennoscandia transition formed in the Paleoproterozoic (2.10-1.75 Ga) through complex geodynamic processes evidenced by multiple subducted mantle slabs. A key process was the subduction of Fennoscandia beneath Sarmatia, recorded by a south-dipping slab from the Keitele microcontinent beneath the Bergslagen microcontinent and the Mid-Baltic Belt, and by an east-to southeast-dipping slab beneath Sarmatia from the Belarus-Podlasie Granulite Belt beneath the Osn & ucy;tsk-Mikashevychi Igneous Belt and the area of the present-day Korosten Pluton. Subduction occurred with interruptions, one of which (ca. 1.89-1.84 Ga) coincided with formation of the Baltic part of the Svecofennian orogen via additional subduction of opposite polarity (north and northeast), as confirmed by slabs from the Amberland microcontinent beneath the Bergslagen microcontinent and from the Central Finland Arc Complex beneath the Karelian craton. Thus, reconciling upper-mantle seismic tomography observations with the geological seismic tomography constraints on crustal evolution provides compelling evidence for a plate-tectonic origin of the processes that led to the formation of the East European Craton.
Over the course of scientific and technical work, the co-authors and their colleagues have developed and tested several modern methods of studying earthquake precursors. One of the methods is unique, its novelty has been recorded in the form of a patent for a utility model. Some other methods have been effectively tested many times, and successful forecast results have been obtained. All the methods listed below can be classified as spatiotemporal or parametric-temporal according to scientific directions. Such a simplified classification of earthquake precursor methods makes it possible to evaluate the results of their work efficiency and reliability according to the properties of their use.
Calculations of geothermal parameters of the Dnieper-Donetsk basin have been carried out. In all fields in part of wells the geothermal gradient is stable and is 20—21 °C/km, and in some it changes. It is negative to the west of the Chernihiv segment, where there are no fields. In its eastern part and the and western part of the Lokhvytsia segment, both positive and negative changes have been observed. In the eastern part of the Lokhvytsia segment and in the near-border parts of the Izyum block, they are exclusively positive. Heat flux within the depression varies from 36 to 56 mW/m2, but over most of the territory it is 39—46 mW/m2. The most common values are 40—42 mW/m2. At the border of the Chernihiv and Lokhvytsia segments, in the southern near-border part and between the Lokhvytsia and Verkhovtsiv-Lgov fault zones (FZ), HF is increased to 45—48 mW/m2. The central part of the Izyum segment is characterized by low HF values (38—40 mW/m2). A major increase happens to the east of Western Azov Region towards Donbas. The spatial distribution of heat flux and temperatures at a depth of 3000 m correlates with the location of the foundation FZ. To the west of the Lokhvytsia FZ, HF changes in areas where the north-eastern stretch zone intersects with the meridional zones. In the triangle between the Lokhvytsia to Verkhovtsiv-Lgov FZs, the influence of the latitudinal FZs (Kyiv—Hadyach and Andrushivka) is also evident. In the central part of the Izyum segment, the distribution of HF corresponds with the location of the latitudinal Starobilsk-Zhmerynka and longitudinal Axial FZs. It is suggested that the increase in the gradient is a parameter of the thermal field that reflects modern tectonic and geological events: the recovery of permeable zones in the sedimentary strata which are related to the faults in the foundation and sedimentary layers, and temperature increase because of the injection of thermal hydrocarbonate-sodium deep waters. The depth of the gradient change is close to the depth of the strata containing hydrocarbon deposits. In the Lokhvytsia segment, gradient changes in the Lower Carboniferous layers, which contain hydrocarbon deposits. In Izyum, the wells do not reach the Lower Carboniferous sediments, and the hydrodynamic regime is caused by the spread of impermeable salt diapirs.
The article presents the principal procedures for kinematic and dynamic processing of wavefields observed using the deep Wide-Angle Reflection and Refraction seismic profiling method. It demonstrates that combining their results enhances the level of subsequent interpretation. Kinematic processing of seismic data is a conventional approach, typically based on ray-tracing modeling, which produces a calculated velocity model of the medium. These velocity parameters are the input data for dynamic processing. Dynamic processing operates with the amplitude-frequency and phase characteristics of the wavefield, involving the construction of an image of the deep section with its existing interfaces and tectonic features of the study area. In global practice, the main procedures of dynamic processing include various migration techniques; however, they are not designed for processing WARR data recorded at large distances of several hundred kilometers from the source. At the S. Subbotin Institute of Geophysics of National Academy of Sciences of Ukraine, a specialized finite-difference migration method for reflected/refracted waves has been developed specifically for Wide-Angle Reflection and Refraction data processing. Both kinematic and dynamic processing were applied to wavefields recorded along the EUROBRIDGE'97 seismic profile. Two alternative velocity models are presented, showing a similar overall structure along the profile down to a depth of 15 km, along with a migrated image to the same depth obtained using the finite-difference migration method for reflected/refracted waves. Application of dynamic processing to the seismic dataset has, for the first time, produced an image of the deep structure of the crystalline basement along the EUROBRIDGE'97 profile, providing additional structural details to the results of kinematic processing.
The article presents the results of magnetotelluric sounding and magnetovariational profiling studies carried out in 2024 within the Precarpathian Trough to investigate the deep structure of the lithosphere searching for electrical conductivity anomalies that may be caused by the penetration of fluids from the crust and mantle into the upper layers of the geological section and may serve as an important source for all subsequent processes of oil and gas field formation. Synchronous modern magnetotelluric surveys were performed along the Bylychi-Hlyboka profile at fourteen observation sites, providing a space-time pattern of the distribution of geomagnetic variations and the electric field on the Earth's surface. The experimental data were processed using the PRC_MTMV software package, and the response functions-tippers for geomagnetic variation periods ranging from 30 to 3400 s - and the curves of apparent resistivity (amplitude values and impedance phases) for periods ranging from 10 to 10000 s were analyzed. According to the results of the joint analysis of MT sounding and magnetovariational profiling data, the profile is divided into two parts. In the northern part the upper boundary of the conductor lies at depths of 20-50 km. It is located within the area of concentration of oil and gas fields of the Boryslav-Pokutskyi district and modern seismic activity. This northern part may represent a continuation of the sublatitudinal asthenospheric conductor identified in previous studies. The southern part is characterized by the presence of conductors at depths of about 20 km. The new geoelectric parameters described in the paper will be further used in constructing a three-dimensional model of the geologically complex Carpathian region.
The article is devoted to integrated geological and geophysical investigations of land-sea transition zones of the Azov-Black Sea region (the Western Black Sea area and the Kerch Bay-Azov Sea). These zones, which are strategically important for hydrocarbon exploration, cover more than 30,000 km(2) and are extremely challenging for the application of conventional seismic exploration methods. This is primarily due to specific physical-geographical conditions and technological limitations. Such studies are critically important for reducing the risk of << dry >> drilling and attracting investment, as well as for addressing engineering and safety issues in the context of post-war reconstruction. A detailed analysis of two key areas the Western Black Sea area and the Kerch Peninsula is presented. In the Western Black Sea area, the most promising zone extends from Lake Sasyk to Lake Alibey, with a forecast estimate of undiscovered resources of 20-30 thousand tonnes of oil equivalent (TOE) per 1 km(2), associated with Paleozoic (Silurian, Devonian, Carboniferous) and Mesozoic deposits. The Kerch area is also among the most promising regions (20-30 thousand TOE per 1 km(2)), where hydrocarbon potential has been proven in Neogene (Tortonian) and Oligocene deposits and is also expected in older complexes (Cretaceous and Jurassic). In the transition zones of the northeastern part of the Kerch Peninsula (Kerch Bay-Azov Sea), exploration seismic surveys using the 2D CMP (CDP) method were conducted by the State Enterprise << Ukrgeophysica >> during 2009-2011. Five seismic profiles with a total length of 43.64 km were acquired; they cross anticlinal structures including the Velykotarkhansky and Baksynsky mud volcanoes. The obtained migrated time sections allowed for a detailed reconstruction of the geological structure of the transition zone and the internal structure of mud volcanoes, confirming their genetic relationship with anticlinal folds. Seismic methods, particularly the 3D seismic surveying, represent the only effective tool for identifying and delineating prospective structures in transition zones. Comprehensive geophysical investigation of these areas is critically important not only for realizing Ukraine's energy potential but also for engineering geophysics (mapping weak soils, designing landslide protection structures) and seismic microzonation. These studies provide a scientific basis for the sustainable development of transport infrastructure and for ensuring the safety of coastal territories.
AM(w) 4.1 earthquake occurred in northern Thailand (19.498 degrees N, 98.518 degrees E) on 09 November 2023 (centroid time: 07:30:19.86 UTC), within the seismically active Shan-Thai terrane. Source parameter determination employed full-waveform inversion utilizing three-component seismic data from ten regional stations at distances of 73-108 km, operated by the Thai Meteorological Department's seismic monitoring network, the Department of Mineral Resources network of Thailand, and the Myanmar National Seismic Network. The inversion methodology utilized the ISOLA software package, implementing iterative deconvolution based on the six-element moment tensor framework, and incorporated a minimal 1D velocity model with station corrections specifically calibrated for northern Thailand. Data preprocessing included instrumental response removal, baseline corrections, and band-pass filtering. Green's functions were computed using the frequency-wave number integration technique within a 0.03-0.10 Hz frequency band. Moment tensor inversion yielded a predominantly strike-slip mechanism with two nodal planes: plane 1 (strike=1 degrees, dip=59 degrees, rake=-148 degrees) and plane 2 (strike=253 degrees, dip=63 degrees, rake=-35 degrees) with 75 % double-couple and-1.2 % CLVD components. Grid search analysis systematically explored source depths from 0-35 km and determined an optimal centroid depth of 2.5 km, with maximum correlation coefficients exceeding 0.4 within the 2-4 km depth range. Waveform analysis demonstrates variance reduction values ranging from 0.40 to 0.80 at near-regional stations (Delta<250 km), indicating robust source parameter determination. The focal mechanism and seismicity distribution indicate strain release along an NE-SW trending structure, located 17 km west of the N-S trending Wiang Haeng fault system.
