Environmental and Earth Sciences

Abstract: The Rudny Altai belt of Kazakhstan, Russia, and China is a major volcanogenic massive sulfide (VMS) province of the Central Asian Orogenic Belt, hosting numerous Zn–Pb–Cu deposits within Devonian volcanic and volcano-sedimentary successions. This study in-tegrates geological and metallogenic data from 29 VMS deposits to quantify regional metal specialization and evaluate its relationships with stratigraphy and volcanic setting. Indi-vidual Zn/(Zn+Pb) values range from 0.56 to 0.93, whereas district means vary from 0.663 to 0.803, indicating a persistent regional Zn-rich tendency superimposed on substantial deposit-scale variability. Stratigraphic analysis demonstrates that mineralization occurs at several discrete Devonian lithochronological levels rather than along a single continuous ore-bearing horizon. Major deposits are commonly associated with felsic volcanic and volcano-sedimentary successions; however, variations in Cu/(Cu+Zn) and compiled δ³⁴S data demonstrate substantial deposit-scale variability in metal distribution. Comparison with major VMS provinces shows that Rudny Altai district-scale Zn/(Zn+Pb) values over-lap with reference values for the Bathurst district and Green Tuff Belt. The results define the Rudny Altai as a Zn–Pb–Cu-dominated VMS province characterized by a regional as-sociation between mineralization and felsic-bearing Devonian successions rather than a simple direct control of felsic magma composition on Zn enrichment. The proposed prov-ince-scale framework provides a quantitative basis for metallogenic comparison and iden-tification of favourable stratigraphic intervals for VMS exploration.

Abstract: Shale gas has been found in the Mesozoic Yanchang Formation in the southern Ordos Basin over recent years. To date, however, whether its gas source rocks are dominated by coalbed methane, biogas, or shallow associated gas has not been examined systematically. In this contribution, the genesis of Mesozoic shale gas in the southern Ordos Basin is investigated by contrasting the geochemical signatures—gas composition and carbon isotopes—of several genetic gas types, namely Mesozoic shale gas, Mesozoic shallow gas, Upper Paleozoic natural gas, and biogenic gas from neighbouring basins. For the Mesozoic shale gas in the southern Ordos Basin, methane content lies between 46.08% and 94.56%, heavy hydrocarbon content between 2.86% and 37.61%, and methane carbon isotope values between −52.0‰ and −46.4‰. On the basis of comparative analysis of gas components and carbon isotopes, it is concluded that the Yanchang Formation shale gas of the Ordos Basin is neither Upper Paleozoic coal-type gas nor biogenic gas; instead, its geochemical fingerprint resembles that of shallow gas within the basin, and it represents a crude oil-associated gas generated by pyrolysis of sapropelic-type source rocks in the Yanchang Formation. Accordingly, the shale gas of the Mesozoic Yanchang Formation in the Ordos Basin is identified as pyrolytic gas whose source rocks can only be the Yanchang Formation itself. These findings offer theoretical support for shale gas exploration in the southern part of the basin.

Abstract: A large earthquake is still considered to be a natural catastrophic event causes immeasurably great material damage and also takes the lives of thousands of people. This is why reducing the earthquake occurrence risk is a critical issue, and researches in this area are of crucial importance for all seismically active countries. One of the most important achievements of seismology in recent decades is related to the study of earthquake initiation. Namely, natural and man-made impacts on seismicity have been considered. The attention is focused on experimental data that testifies to the existence of actively influencing the seismogenic environment with electrical impulses in order to smoothly relieve accumulated tectonic stresses by initiating earthquakes in the Earth's crust. Because at the moment of occurrence of an earthquake approaches, the focal zone becomes increasingly sensitive to external influences, it is clear that the problem of intentional initiation of earthquakes by explosion is closely connected with the problem of earthquake prediction. This article presents a completely new perspective on the possibilities of the earthquakes occurrence risk reduction and artificial release of accumulated tectonic stress in the earthquake preparation zone, based on the latest research on the possibilities of hourly earthquake prediction.

Abstract: Quantifying coastal spatial complexity across continuous display scales in digital mapping architectures is traditionally constrained by static raster resolution boundaries, quantization errors, and manual operator bias. Furthermore, dynamic web-mapping services deploy scale-dependent cartographic generalization, causing displayed geometries to reflect geospatial database complexity rather than static physical boundaries. To address these challenges, this study presents an automated, hybrid Web-GIS and MATLAB geospatial processing pipeline that integrates commercial web-mapping API vector-rendering engines with digital image processing to facilitate continuous multi-scale cartographic complexity (D_b) benchmarking and feature extraction. By maintaining a constant physical-scale measuring grid—calibrated via a dimensionless coordinate-ratio parameter—over programmatically scaled vector cartography, the pipeline leverages sub-pixel geometric precision to achieve seamless multi-scale coastal feature extraction. The framework incorporates connected-component labeling (CCL) noise filtration, Otsu thresholding, Canny edge detection, Gecko-engine tile rendering to eliminate WebKit-induced stitching grid artifacts, and latitudinal scale-distortion compensation for Web Mercator projections. Deployed across 16 global geospatial databases, the pipeline demonstrates robust spatial benchmarking capabilities: along Norway's glaciated coastline (D_b=1.4395), it effectively captures a scale-dependent, biphasic "fjord-to-fjard" morphometric transition, resolving spatial thresholds corresponding to meso-scale glacial valley morphometry. Global database benchmarking reveals clear structural distinctions in cartographic complexity, where active convergent boundaries exhibit elevated fractal complexity (e.g., Southeast Asia, D_b=1.4578) compared to transform-suppressed margins (e.g., US West Coast, D_b=1.0460). Additionally, a macro-scale cartographic low-pass filter (>0.8 km, Zoom 2–7) effectively attenuates high-frequency cartographic noise and anthropogenic structural inflation (e.g., 56.29% artificial coastlines in Taiwan). This open-source workflow provides a robust, reproducible Web-GIS framework for dynamic spatial database benchmarking, digital cartographic analysis, and automated coastal feature extraction.

Abstract: Most traces of past impacts with cosmic bodies that occurred on Earth during Time have been erased by geological processes, such as subduction and erosion, have been hidden by sedimentation and volcanism, or have been covered by seawater; the Moon, the Earth’s natural satellite, may be considered our best scientific laboratory for impact cratering processes. The number of accepted and recorded impact craters on Earth suddenly increased when observations have been taken from the above the Earth from airplanes, satellites and drones. The number of accepted and recorded old impacts on Earth recently started to increase when scientists turned toward the deeply located buried craters, using Geophysics. The available recorded impacts have been completed with re-cently published large diameter of buried impact structures: Precaspian Depression, situated in Kazakhstan and Russia (ca 700 km), Alexandria Depression, situated in Romania and Bulgaria (ca 175 km) and Transylvanian Depression, situated in Romania (ca 300 km). The recorded impacts suggest that a correlation with life extinction events can be made in Devonian (Fras-nian-Famennian) and at the Cretaceous-Tertiary boundary, Chicxulub event being known world-wide. It is likely that large diameter impactors on Earth might represent a necessary condi-tion for relating impacts with cosmic bodies to high extinction events. Large diameter asteroids, interpreted to have created the Precaspian and Alexandria depressions during the Permian may be well correlated with the Maokouan (50% life extinction) and Changhsingian (78% life extinction). On the three discussed study cases, the Bouguer gravity anomaly was the main geophysical in-formation for detecting a buried impact structure; besides the traditional gravity low, high gravity anomalies associated with the uplifted Crater rim and Central peak are being interpreted. The magnetic anomalies of the Precaspian region illustrate a circular sector with high magnetic anom-alies, interpreted as effects of the uplifted magnetic basement along the Crater rim and partly, effect of the magnetic “step effect” above abruptly ended magnetic geological formations. The magnetic anomalies over the Alexandria Depression proved to be weak and less associated to the impact structure; the crater uplifted sectors have been probably eroded and its infrastructure masked by the effect of thick lava flows, embedded in the depression sedimentary infill. The magnetic data of the Transylvanian Depression contradicts the usual way magnetic anomalies are interpreted above impact structures, a large and intense high magnetic anomaly being measured, instead of a large magnetic low. This anomaly, aided by a magnetic 2D modeling, was interpreted as effect of a huge magmatic structure, a batholith, intruded suite of geological processes determined by the asteroid impact.

Abstract: Artificial intelligence (AI) is increasingly being used to support the assessment of geomechanical containment risk in geological CO₂ storage; however, the suitability of different model families remains strongly dependent on the task, data representation, and target variable. This systematic review followed PRISMA 2020 and analyzed 63 studies published between 2021 and 2026, identified through IEEE Xplore, Web of Science, ScienceDirect, and Scopus. The evidence was synthesized according to AI family, application, inputs, outputs, dataset origin, validation strategy, predictive performance, computational efficiency, and relationship with geomechanical containment risk. CNN/U-Net, FFNN/MLP/DNN, and conventional machine-learning methods were the most frequently used families, while FNO, recurrent models, GNN, PINN, GAN/cGAN, and reduced-order approaches addressed more specialized spatial, temporal, physical, and optimization tasks. Only 17 studies (27%) predicted at least one direct geomechanical response or risk indicator, whereas 42 studies (66.7%) relied exclusively on synthetic or simulation-generated data. AI surrogates consistently reduced computational cost, enabling rapid scenario evaluation and optimization, but field validation of directly geomechanical models remained limited. Overall, no universally superior architecture was identified; model suitability is task-dependent. Future progress requires hybrid datasets, external field validation, uncertainty quantification, and reproducible workflows integrating AI with multiphysics simulation and monitoring data.

Abstract: Publicly available data and information relevant and supportive to the 26 August 2026 Langtang Lirung disaster cascade are dispersed across repositories, data portals and other online sources, complicating their identification, assessment and reuse. This study presents a living catalogue (https://evelpidou.nkua.cloud/Nepal-Flood-2026-Catalogue/) of these resources and analyses its first assessed release, archived in Zenodo (https://doi.org/10.5281/zenodo.23034746). The search and charting process, reported in accordance with PRISMA-ScR, comprised 74 documented searches through 24 September 2026, followed by the assessment and reviewing that completed on 28 September. The resulting inventory contains 141 resources and 5,883 assets across eight thematic domains. Structured records preserve provenance, geographic and temporal descriptions, access conditions, rights and source limitations, while the WebGIS (https://evelpidou.nkua.cloud/Nepal-Flood-2026/) enables geographic exploration where spatial information is available. Beyond this initial release, planned periodic searches, event-triggered checks, community nominations and versioned updates provide for continued expansion. The contribution is a traceable inventory connecting pre-event baselines, event observations and subsequent analyses to their supporting material, with documented searches and decisions providing a basis for continued maintenance. The catalogue therefore reduces the time and effort required to identify and access relevant data and information, while lowering the risk of overlooking resources that could inform future investigations of the event. Unlike conventional scoping reviews centred on mapping existing studies or datasets, this approach proposes a new type that systematically identifies and evaluates the data and resources available to support future research.

Abstract: The Romilly region, situated at the junction of two major geological features of the Paris Basin, exhibits numerous Quaternary deformations. The origin of these deformations has been the subject of conflicting publications: seismites versus periglacial. The existence in Gélannes of an anthropogenic pit dating from the Late Bronze Age, affected by a fault approximately 0.35 m high, has reignited the debate. Thus, periglacial deformations may have been reactivated by a Holocene earthquake, thereby explaining, amongst other things, the flame-like structures and faults. This is all the more likely given that Holocene faults are found at Sauvage, as are late-stage injections of chalk mud reaching the surface. The intersection of the Saint Martin and Sézanne faults could be the cause of the observed deformations. Petroleum seismic surveys thus show that, locally, the Saint Martin fault extends up to the top of the chalk. The epicentre is likely to be found near the most deformed sites at Marcilly and Sauvage. This seismic hypothesis also corroborates the conclusions of Damon et al. (2023). This author suggests a potential current slip on the Vittel and Saint Martin faults, as a result of the melting of the Scandinavian glaciers. It is also interesting to note a higher local geothermal flux at Saint Just Sauvage (98 mW/m² compared with 86 mW/m² in the Paris Basin), likely linked to heterogeneities at the base of the crust. This author suggests that the Vittel and Saint Martin faults may currently be active again, as a result of the melting of the Scandinavian glaciers. It is also interesting to note a higher geothermal flux locally at Saint Just Sauvage (98 mW/m² compared with 86 mW/m² in the Paris Basin), which is likely linked to heterogeneities at the base of the crust. This type of thermal anomaly is sometimes put forward as an explanation for intraplate earthquakes.

Abstract: Characterizing thin sandstone reservoirs remains challenging where strong lateral heterogeneity and limited seismic resolution make individual sand bodies difficult to distinguish. This study presents an integrated approach to reservoir characterization using 3D seismic and well-log data from a mature oilfield. Conventional seismic attributes, Highlight analysis, and spectral decomposition were combined with post-stack sparse-spike acoustic impedance inversion and AI-assisted high-resolution geostatistical inversion. Amplitude and Highlight attributes revealed consistent sandstone distribution patterns, while spectral decomposition identified distinct frequency responses at 55, 60 and 70 Hz across the investigated intervals. Conventional acoustic impedance inversion reproduced the main sandstone units but only partially resolved individual sand bodies approximately 2-8 m thick. The high-resolution geostatistical gamma-ray (GR) inversion sections revealed finer lithological variations than the conventional acoustic impedance inversion results. The upper intervals showed relatively continuous sandstone development, whereas the deeper intervals exhibited thinner sand bodies, greater siltstone development, and more pronounced lateral heterogeneity. These findings demonstrate the value of combining complementary seismic interpretation and inversion techniques to characterize complex sandstone reservoirs. The resulting geological interpretation provides a basis for further assessment of reservoir compartmentalization and potential interwell connectivity.

Abstract: The North Sinai Offshore Basin (NSOB), located along the southern margin of the Eastern Mediterranean Basin (EMB), represents a strategically important yet relatively underexplored hydrocarbon province situated between the prolific Nile Delta and Levant basins. This study reconstructs the tectono-stratigraphic evolution of the NSOB through the integration of regional two-dimensional seismic reflection data, well information, seismic stratigraphy, structural interpretation, and seismic attribute analysis to evaluate the controls of tectonic inheritance on basin evolution, sediment routing, and hydrocarbon prospectivity. The results demonstrate that the basin architecture was established during Permian–Triassic to Early Jurassic Neo-Tethyan rifting, which generated a network of basement-involved normal faults, horsts, grabens, and half-grabens that governed subsequent sediment accumulation. Jurassic–Early Cretaceous thermal subsidence promoted passive-margin development and widespread carbonate-platform deposition, whereas Late Cretaceous–Eocene Syrian Arc compression reactivated inherited extensional faults to produce inversion anticlines and structural culminations that significantly modified basin morphology. Oligocene–Miocene extensional reactivation associated with Red Sea and Gulf of Suez opening further compartmentalized the basin, creating accommodation space for deep-water depositional systems, including submarine channels, channel–levee complexes, basin-floor fans, and mass-transport deposits. Seismic attribute analyses reveal that these depositional elements are strongly controlled by long-lived basement structures, highlighting the persistent influence of structural inheritance on sediment dispersal and reservoir distribution. The Late Miocene Messinian evaporite succession forms a regionally extensive seal that preserves pre-existing structural and stratigraphic traps, enhancing hydrocarbon retention. This integrated tectono-stratigraphic framework demonstrates that repeated structural reactivation, rather than independent tectonic episodes, governed the long-term evolution of the NSOB. The study provides new insights into the evolution of structurally inherited passive-margin basins and establishes a predictive exploration model for identifying prospective structural and stratigraphic hydrocarbon plays across the Eastern Mediterranean Basin.

Abstract: Unmanned surface vehicles (USVs) have emerged as a new type of marine carrier platform and are attracting increasing attention in marine geological surveying owing to their flexibility, low observability and unmanned operation. This review systematically traces the development history and current status of USVs worldwide and in China, and summarizes the state of the art of USV-based marine geological survey technology from three perspectives: autonomous control, sensor integration, and data transmission and processing. Two representative applications, seafloor topographic and geomorphological surveying and sub-seafloor geophysical exploration, are examined to illustrate engineering practice. Recent advances and technological trends are then outlined in terms of cross-domain collaborative operations, upgrading of core equipment, expansion of application scenarios and standardization. Remaining challenges are analyzed, including limited adaptability to complex environments, insufficient autonomous decision-making, data quality control and the low domestic production rate of core components, and future development directions are proposed. With continued technological progress, deeper research and improvement of the relevant survey standards, USVs are expected to mature into a stand-alone technical means for marine geological surveying.

Abstract: In May 2023, the Emilia-Romagna region (northern Italy) was hit by two unexpected extreme weather events that caused 17 deaths, the displacing of 50,000 people, and damages amounting to over 10 billion euros. Such a geo-hydrological disaster has stimulated scientific investigation, and tens of papers have been published. In this review, peer-reviewed publications are examined with the aim of identifying critical issues relevant to the decision-making process. These questions are crucial for policy makers and territorial government agencies, who play a direct and fundamental role in disaster management. The review was performed in accordance with the PRISMA method and by the citation and indexing databases of Scopus and Web of Science (WoS). Its main findings are summarized as follows: (1) in flood and landslide mitigation, land-use planning adequate to the climate-adjusted scenarios must be designed and implemented; (2) early warning systems should be people-centered and based on more advanced weather forecasts or new methods, like the elaboration of cellular geo-referenced data; (3) the use of integrated approaches based on machine learning and other modern technologies is increasing being proposed to improve performance in disaster response. It can be concluded that the reviewed literature informs policy for improving government guidelines, rules, and decision-making in disaster management.

Abstract: Groundwater contamination by ⁹⁰Sr remains an important component of the long-term environmental impact of the Chornobyl accident, while the spatial coverage of monitoring observations limits direct assessment of contamination patterns across the Chornobyl Exclusion Zone (CEZ). This study evaluates the applicability of machine-learning methods for regional assessment of ⁹⁰Sr groundwater contamination and identification of its principal controlling factors. Random Forest (RF) and XGBoost models were developed using groundwater ⁹⁰Sr observations for 2015-2020 and source-related, hydrogeological, geochemical, topographic, and monitoring-well predictors. Performance was evaluated using repeated stratified holdout validation for multiclass classification and complementary regression of log-transformed 90Sr concentrations. Regional contamination classes were subsequently predicted using spatially distributed predictor layers. The RF classifier, predicting order-of-magnitude concentration classes, achieved a mean accuracy of 0.70 and weighted F1-score of 0.66, compared with 0.64 and 0.62 for XGBoost, whereas XGBoost showed slightly higher regression performance (R² = 0.55) than RF (R²= 0.50). Across model-specific, permutation and SHAP analyses, groundwater-table depth, aquifer sampling depth, and surface ⁹⁰Sr contamination were repeatedly identified among the most influential predictors. Spatial predictions indicated that higher contamination classes were localized and primarily associated with the combination of elevated surface contamination and shallow groundwater conditions, with notable correspondence to radioactive-waste disposal areas. The results provide spatial information to support prioritization and development of groundwater monitoring networks in the CEZ.

Abstract: Landslide fracture zones play a critical role in slope instability, yet their hydraulic fracturing processes remain difficult to monitor using conventional geophysical methods. This study proposes a time‐lapse three‐dimensional transient electromagnetic (TEM) imaging approach to characterize fracture damage evolution in the Xiaolongdong–Xiahaizi landslide, Zhaotong City, China. Repeated TEM observations, integrated with GNSS displacement monitoring and environmental measurements, were used to reconstruct dynamic resistivity fields through three‐dimensional inversion. The method achieved localization accuracies better than 1 m horizontally and 2 m vertically and detected water‐filled fractures wider than 0.3 mm. Distinct resistivity precursor anomalies, characterized by a 3%–8% increase followed by a rapid decrease, occurred 2–5 min before fracture propagation. During hydraulic fracturing, resistivity decreased from 30–50 Ω·m to 8–15 Ω·m, reflecting progressive fracture connectivity. Rainy‐season permeability coefficients reached 10⁻⁴–10⁻³ m/s, one to two orders of magnitude higher than those during the dry season. Freeze–thaw processes and rainfall infiltration jointly contributed 25%–35% of slope displacement. The proposed framework provides quantitative visualization of fracture evolution and effective geophysical constraints for landslide stability assessment and early warning.

Abstract: The 26 May 2026, Mw 4.5 Jalalpur earthquake, Pakistan, caused considerable damages around its epicentre. Investigations indicated a VII maximum intensity of the Modified Mercalli Intensity (MMI) scale, diminishing rapidly away from the source. Several earthquake-induced ground effects occurred, including liquefaction, temporary groundwater turbidity, differential settlement, tilting of utility poles and numerous landslides within the Quaternary deposits of the Tilla-Jogian Mountains. Observed pronounced North–South (N–S) ground motion was consistent with coseismic deformation within damaged infrastructure. Moment tensor inversion revealed that the earthquake originated at approximately 3 km depth, was characterized by predominant thrust faulting with a minor left-lateral strike-slip component, indicative of a transpressional tectonic regime. This mechanism is associated with a blind thrust beneath the Pabbi-Anticline and is supported by gravity modeling. Coulomb-stress analysis suggested that the Pabbi-Anticline was brought closer to failure after the 2019 Mw 5.8 Mirpur earthquake. However, seismic activation was delayed due to sustained increase in seismicity beginning in 2022. Both 2024 Mw 5.0 Kharian and 2026 Jalalpur earthquakes, occurred within this prolonged period of seismic activity. These observations suggest that stress transfer from the 2019 Mirpur earthquake, combined with progressive strain accumulation and localization along active structures, contributed to increased seismic hazard.

Abstract: The open-source evaluation of deep geothermal projects faces a structural gap between the physical analysis of subsurface reservoir conditions and the surface-level techno-economic assessment, traditionally bridged through inefficient manual coupling. To address this, an automated computational workflow controlled through a Python coupling interface was developed to integrate 3D thermo-hydraulic reservoir simulations in MRST (MATLAB Reservoir Simulation Toolbox) with the techno-economic tool GEOPHIRES-X. The architecture relies on synchronous batch-mode execution, incorporating a structural bypass of the native homogeneous subsurface models of GEOPHIRES-X. The resulting coupled workflow enables the automatic transfer of MRST reservoir simulation outputs, together with selected geometric parameters required for CAPEX calculations, to the GEOPHIRES-X techno-economic module. The workflow was tested with a case study of a deep geothermal doublet consisting of two J-type directional wells targeting a Jurassic reservoir in the Camp Basin, Catalonia (NE Spain). The coupled analysis quantified the impact of reservoir heterogeneity and three-dimensional flow and heat transport that are not captured by standalone analytical tools: explicit 3D representation of vertical anisotropy and buoyancy effects resulted in a 39.3% reduction in deliverable thermal power. Consequently, compared to the uncoupled baseline, the fully coupled model resulted in a 91.2% reduction in Net Present Value (NPV) and a 71.9% increase in the Levelized Cost of Heat (LCOH), reaching 0.1141 €/kWhₜₕ. Additionally, an automated One-Factor-at-a-Time (OFAT) sensitivity analysis demonstrated that economic performance in the study area is more sensitive to surface operational variables than to the subsurface geological parameters considered. Finally, the proposed open-source coupling framework provides an auditable and reproducible interface between existing reservoir simulation and techno-economic tools, such as MRST and GEOPHIRES-X, enabling faster and more integrated geothermal assessments than separate model execution.

Abstract: Pressure-limited dynamic capacity in the Lopín structure is controlled primarily by reservoir transmissibility rather than by static pore volume. This study applies a MATLAB/MRST vertical-equilibrium (VE) workflow to the Lopín horst, a deep Triassic Buntsandstein aquifer in the Ebro Basin, NE Spain, and evaluates the sensitivity of the results to seven petrophysical, fluid, and operational parameters using a one-at-a-time sensitivity design (35 sensitivity cases plus one base case). Across the tested range, horizontal permeability produced the largest variation in maximum injectable CO₂ mass, from 4.67 to 16.25 Mt (range 11.59 Mt), followed by the adopted BHP threshold (range 5.33 Mt) and CO₂ density (range 4.74 Mt). Porosity and brine compressibility had only minor effects, whereas injection rate and residual CO₂ saturation did not change the BHP-limited capacity under the adopted capacity-search formulation. The base-case operational BHP limit was 28.5 MPa, selected below the site-specific allowable and estimated fracture-pressure thresholds reported for Lopín. These results show that pressure dissipation, hydraulic transmissibility, and the explicit choice of operational pressure criterion are the dominant controls on dynamic CO₂ storage capacity in this fault-bounded saline aquifer.

Abstract: The Vere River basin in Tbilisi, Georgia, experienced a major cascading landslide-flood disaster in June 2015, emphasizing the need to evaluate the present stability of slopes adjacent to the former source area. This study combines Small-Baseline InSAR (SBAS), RTK-UAV photogrammetry, COSI-Corr image correlation and LS-RAPID numerical modelling to investigate whether the slope remains active and how it responds to changing pore-pressure conditions. Analysis of 109 ascending Sentinel-1 acquisitions acquired between April 2022 and October 2025 revealed persistent positive line-of-sight deformation across the investigated slope. Independent UAV/COSI-Corr analysis identified horizontal displacements of approximately 0.05-0.09 m over 149 days, exceeding the empirical relative displacement detection threshold of 0.0235 m. The measured displacement direction broadly follows the downslope and structural orientation, although its angular offset suggests that the movement is influenced by a combination of topography, bedding, fractures, and heterogeneous slope materials rather than a single planar control. LS-RAPID simulations further showed a nonlinear response to increasing prescribed pore-pressure ratio. Together, the observations indicate that the slope has not fully stabilized after the 2015 event and continues to undergo slow deformation while remaining sensitive to hydrological conditions. This is particularly important for Tbilisi because renewed slope instability in the Vere valley could interact with the confined river corridor and urban infrastructure, increasing the potential for cascading impacts.

Abstract: Decades-separated airborne magnetic surveys rarely reproduce amplitude, but a persistent crustal boundary may preserve its geometry. We test this at Uruana de Minas with surveys from 1971–1972, 2008 and 2011. Raw 2011 data show all 14 target lines reverse the positive northward gradient predicted by the International Geomagnetic Reference Field and recover farther north. Independent 2008 data record a bounded positive–negative–positive–positive topology in both scalar data and rotation-invariant triaxial magnitude; together, the two survey gates leave Uruana as the sole joint pass among 82 centers. Historical and 2008 fields recover opposed 7–9 km derivative walls with near-Uruana midpoints, while reciprocal 2008 traverses preserve geographic contrast. Scalar and fluxgate latitudinal residuals differ by 0.015 nT km⁻¹, and the conditional residual direction is 99.883–99.983% tangential. Across 6, 8 and 10 km Hessian supports, six outer curvature roots lie within 0.702 km of the frozen 2011 front, ranking first among 65 translated positions. Under continuation, the outer boundary migrates and disappears by 4 km, whereas the central saddle persists. The surviving frame registers to independently mapped geology. We therefore establish a four-decade, structurally locked magnetic-gradient reversal envelope. Directional deflection remains conditional and Maxwell closure fails; dome closure, circulation and protective effects remain unresolved.

Abstract: Salt (halite) massifs undergoing active dissolution are among the most hazard-prone geological settings for ground instability, and their monitoring requires a reliable geometric model of the salt body and its overburden. This study presents an integrated geoelectrical–geological characterization of the salt formation at Slănic Prahova (Romania), carried out in 2026 within the GEOMONITOR project. Six electrical resistivity tomography (ERT) profiles were acquired along three transects, each surveyed with both Wenner and Schlumberger electrode configurations (5 m electrode spacing), and correlated with lithological logs from three boreholes (F1, F2, F3) that intercepted the salt formation at 98.0 m, 44.1 m and 68.0 m below ground, corresponding to 301.0, 346.4 and 327.0 m a.s.l. respectively. Reading both datasets in absolute elevation is the key step of the workflow: it shows that the salt roof enters the imaged volume only in the Baia Roșie sector, where a body exceeding 1000 Ω·m occupies the 348–370 m a.s.l. interval, i.e. at and just above the shallowest salt roof recorded by drilling, whereas along the other two transects the salt roof lies 35–80 m below the base of the inverted models. The sections delineate a strongly heterogeneous cover, predominantly conductive (1–10 Ω·m) and punctuated by transition zones with steep lateral resistivity gradients. Two consequences follow for hazard-oriented surveys of this kind: shallow resistive anomalies confined to the uppermost meters cannot be attributed to the salt roof, and the absence of a resistive anomaly along a line of this length is not evidence for the absence of salt. The conductive–resistive contact zones, rather than the resistive cores themselves, are identified as the priority targets for hydrogeological monitoring, since they can concentrate permeability contrasts and control dissolution. The elevation-based reconciliation of ERT and borehole data proposed here is transferable to other salt karst settings.