Geosciences

24 pages, 4639 KiB

Open AccessArticle

Testing Satellite Snow Cover Observations Using Time-Lapse Camera Images in Mid-Latitude Mountain Ranges (Northern Spain)

by Adrián Melón-Nava and Javier Santos-González

Geosciences 2025, 15(8), 316; https://doi.org/10.3390/geosciences15080316 - 13 Aug 2025

Abstract

Reliable monitoring of snow cover in mountainous regions remains a challenge due to frequent cloud cover and the revisit limitations of optical satellites. This study compares satellite snow-cover records with >99,000 ground-based time-lapse camera observations across northern Spain (2003–2025). Cloud cover caused major [...] Read more.

Reliable monitoring of snow cover in mountainous regions remains a challenge due to frequent cloud cover and the revisit limitations of optical satellites. This study compares satellite snow-cover records with >99,000 ground-based time-lapse camera observations across northern Spain (2003–2025). Cloud cover caused major data loss, with up to 57% of satellite images affected. Effective revisit intervals (the average time between usable images) diverge substantially from nominal values: 2.3 days for MODIS, 6.9 days for Sentinel-2, and over 21 days for Landsat. A hierarchical multisensor approach with 5-day gap-filling reduced this to just 1.3 days. On dates when cameras confirmed snow, satellites underestimated snow presence by 61.6% (Sentinel-2), 71.5% (Landsat), and 79.7% (MODIS), though gap-filling approaches reduced underestimation to 49.4%—deficits largely attributable to cloud-obscured scenes. When both satellite and camera provided cloud-free observations for the same date and location, classification agreement exceeded 85%. Despite this, satellites consistently failed to detect short-lived snow events and introduced temporal biases. On average, Snow Onset Dates were detected 13–52 days later, and Snow Melt-Out Dates differed by up to 40 days compared to camera-derived records. These results have implications for snow-cover monitoring using satellite images and highlight the need for integrating ground-based observations to compensate for satellite limitations and improve snow cover seasonality assessments in complex terrains. Full article

(This article belongs to the Section Cryosphere)

► Show Figures

Figure 1

24 pages, 10900 KiB

Open AccessArticle

GIS-Based Process Automation of Calculating the Volume of Mineral Extracted from a Deposit

by Anna Szafarczyk and Michał Siwek

Geosciences 2025, 15(8), 315; https://doi.org/10.3390/geosciences15080315 - 12 Aug 2025

Abstract

The recording of minerals extracted from a deposit is crucial for effective planning, exploitation management, and compliance with legal requirements. It also enables improved workplace safety and the minimization of negative environmental impact. Automation in mining optimizes exploitation, transportation, and data management processes, [...] Read more.

The recording of minerals extracted from a deposit is crucial for effective planning, exploitation management, and compliance with legal requirements. It also enables improved workplace safety and the minimization of negative environmental impact. Automation in mining optimizes exploitation, transportation, and data management processes, resulting in better forecasting, more accurate resource calculations, and reduced operational costs. The usage of geographic information system tools facilitates data modeling and analysis, enhancing monitoring and mining exploitation management. This paper presents the classical approach to determining the volume of extracted minerals and proposes GIS-based tools for the automation of the volume calculation process. The automation of the process is presented both from a theoretical perspective, providing requirements and parameters for individual calculation procedures, and from a practical perspective, using the example of a typical open pit mine, where the procedure is implemented starting from field measurements, carrying out calculations, and ending with visualization and interpretation. The study highlights the benefits of automating the calculation procedure for the volume of extracted minerals, including task execution acceleration, increased efficiency, reduced calculation time, and minimized human error. This ultimately leads to more precise and consistent results. Full article

► Show Figures

Figure 1

54 pages, 10419 KiB

Open AccessReview

State-of-the-Art Review and Prospect of Modelling the Dynamic Fracture of Rocks Under Impact Loads and Application in Blasting

by Muhammad Kamran, Hongyuan Liu, Daisuke Fukuda, Peng Jia, Gyeongjo Min and Andrew Chan

Geosciences 2025, 15(8), 314; https://doi.org/10.3390/geosciences15080314 - 12 Aug 2025

Abstract

The dynamic fracture of rocks under impact loads has many engineering applications such as rock blasting. This study reviews the recent achievements of investigating rock dynamic fracturing and its application in rock blasting using computational mechanics methods and highlights the prospects of modelling [...] Read more.

The dynamic fracture of rocks under impact loads has many engineering applications such as rock blasting. This study reviews the recent achievements of investigating rock dynamic fracturing and its application in rock blasting using computational mechanics methods and highlights the prospects of modelling them with a hybrid finite-discrete element method (HFDEM) originally developed by the authors. The review first summarizes the peculiarities of rock dynamic fracturing compared with static fracturing, which are that the physical-mechanical properties of rocks, including stress wave propagation, strength, fracture toughness, energy partition and cracking mechanism, depend on loading rate. Then the modelling of these peculiarities and their applications in rock blasting using fast developing computational mechanics methods are reviewed with a focus on the advantages and disadvantages of prevalent finite element method (FEM) as representative continuum method, discrete element method (DEM) as representative discontinuum method and combined finite-discrete element (FDEM) as representative hybrid method, which highlights FDEM is the most promising method for modelling rock dynamic fracture and blasting application as well as points out the research gaps in the field of modelling the dynamic fracture of rocks under impact loads. After that, the progress of shortening some of these gaps by developing and applying HFDEM, i.e., the authors’ version of FDEM, for modelling rock dynamic fracture and applications in rock blasting are reviewed, which include the features of modelling the effects of loading rate; stress wave propagation, reflection and absorbing as well as stress wave-induced fracture; explosive-rock interaction including detonation-induced gas expansion and flow through fracturing rock; coupled multiaxial static and dynamic loads; heterogeneous rock and rock mass with pre-existing discrete fracture network; and dynamic fracturing-induced fragment size distribution. Finally, the future directions of modelling the dynamic fracture of rocks under impact loads are highlighted and a systematic numerical approach is proposed for modelling rock blasting. Full article

(This article belongs to the Section Geomechanics)

► Show Figures

Figure 1

38 pages, 13807 KiB

Open AccessArticle

A Sediment Provenance Study of Middle Jurassic to Cretaceous Strata in the Eastern Sverdrup Basin: Implications for the Exhumation of the Northeastern Canadian-Greenlandic Shield

by Michael A. Pointon, Helen Smyth, Jenny E. Omma, Andrew C. Morton, Simon Schneider, Stephen J. Rippington, Berta Lopez-Mir, Quentin G. Crowley, Dirk Frei and Michael J. Flowerdew

Geosciences 2025, 15(8), 313; https://doi.org/10.3390/geosciences15080313 - 12 Aug 2025

Abstract

The Sverdrup Basin, Arctic Canada, is ideally situated to contain an archive of tectono-magmatic and climatic events that occurred within the wider Arctic region, including the exhumation of the adjacent (northeastern) part of the Canadian-Greenlandic Shield. To test this, a multi-analytical provenance study [...] Read more.

The Sverdrup Basin, Arctic Canada, is ideally situated to contain an archive of tectono-magmatic and climatic events that occurred within the wider Arctic region, including the exhumation of the adjacent (northeastern) part of the Canadian-Greenlandic Shield. To test this, a multi-analytical provenance study of Middle Jurassic to Cretaceous sandstones from the eastern Sverdrup Basin was undertaken. Most of the samples analysed were recycled from sedimentary rocks of the Franklinian Basin, with possible additional contributions from the Mesoproterozoic Bylot basins and metasedimentary shield rocks. The amount of high-grade metamorphic detritus in samples from central Ellesmere Island increased from Middle Jurassic times. This is interpreted to reflect exhumation of the area to the southeast/east of the Sverdrup Basin. Exhumation may have its origins in Middle Jurassic extension and uplift along the northwest Sverdrup Basin margin. Rift-flank uplift along the Canadian–West Greenland conjugate margin and lithospheric doming linked with the proximity of the Iceland hotspot and/or the emplacement of the Cretaceous High Arctic Large Igneous Province may have contributed to exhumation subsequently. The southeast-to-northwest thickening of Jurassic to Early Cretaceous strata across the Sverdrup Basin may be a distal effect of exhumation rather than rifting in the Sverdrup or Amerasia basins. Full article

(This article belongs to the Special Issue Editorial Board Members' Collection Series: “Sedimentology and Stratigraphy”)

► Show Figures

Figure 1

51 pages, 29464 KiB

Open AccessReview

Impact of Aerosols on Cloud Microphysical Processes: A Theoretical Review

by Kécia Maria Roberto da Silva, Dirceu Luís Herdies, Paulo Yoshio Kubota, Caroline Bresciani and Silvio Nilo Figueroa

Geosciences 2025, 15(8), 312; https://doi.org/10.3390/geosciences15080312 - 11 Aug 2025

Abstract

The direct relationship between aerosols and clouds strongly influences the effects of clouds on the global climate. Aerosol particles act as cloud condensation nuclei (CCN) and ice nuclei (IN), affecting cloud formation, microphysics, and precipitation, as well as increasing the reflection of solar [...] Read more.

The direct relationship between aerosols and clouds strongly influences the effects of clouds on the global climate. Aerosol particles act as cloud condensation nuclei (CCN) and ice nuclei (IN), affecting cloud formation, microphysics, and precipitation, as well as increasing the reflection of solar radiation at the cloud tops. Processes such as gas-to-particle conversion and new particle formation (NPF) control aerosol properties that, together with meteorological conditions, regulate cloud droplet nucleation through Köhler theory and related effects. The indirect aerosol effects described by Twomey and Albrecht demonstrate how changes in aerosols impact droplet number, cloud lifetime, and precipitation efficiency. Cloud microphysical processes, including droplet growth, collision-coalescence, and solid-phase mechanisms such as riming, vapor diffusion, and aggregation, shape precipitation development in warm, cold, and mixed-phase clouds. Ice nucleation remains a significant uncertainty due to the diversity of aerosol types and nucleation modes. This work synthesizes these physical interactions to better understand how the chemical and physical properties of aerosols influence cloud and precipitation processes, supporting improvements in weather and climate prediction models despite numerical challenges arising from the complexity of aerosol–cloud interactions. Full article

(This article belongs to the Section Climate and Environment)

► Show Figures

Figure 1

40 pages, 14629 KiB

Open AccessArticle

Assessing the Geothermal Potential of a Fractured Carbonate Reservoir (Southern Apennines, Italy): Relationships Between Structural Control and Heat Flow

by Chrysanthi Pontikou, Ioannis Vakalas, Sotirios Kokkalas, Raffaele Di Cuia, Angelo Ricciato and Giovanni Toscani

Geosciences 2025, 15(8), 311; https://doi.org/10.3390/geosciences15080311 - 11 Aug 2025

Abstract

As part of the energy transition needed to mitigate global warming, the study and sustainable exploitation of geothermal resources—a largely underutilized form of energy and heat production—is crucial. The availability of subsurface data acquired for oil and gas exploration purposes provides an opportunity [...] Read more.

As part of the energy transition needed to mitigate global warming, the study and sustainable exploitation of geothermal resources—a largely underutilized form of energy and heat production—is crucial. The availability of subsurface data acquired for oil and gas exploration purposes provides an opportunity to reconsider these data to enhance the use of geothermal potential. This is the case of a fractured carbonate reservoir in the Southern Apennines (Italy). All available subsurface data were gathered, homogenized, and reinterpreted to build a 3D geological model of the study area, where a positive thermal anomaly is known, yet the mechanisms and pathways of heat transport were previously unclear. By integrating subsurface, temperature, and literature data, a geological model is proposed that explains how high temperatures and heat propagation are closely linked to specific geological features. By cross-referencing and weighing the relevance of data for geothermal purposes, an attempt is made to rank the geothermal potential of existing wells in the area. This study demonstrates how a well-constrained geological model and the joint analysis of multidisciplinary data can provide the necessary knowledge base for conducting further technical, engineering, and economic analyses to assess the commercial viability of the identified geothermal resource. Full article

(This article belongs to the Section Structural Geology and Tectonics)

► Show Figures

Figure 1

2 pages, 132 KiB

Open AccessCorrection

Correction: Telesca et al. Statistical Investigation of the 2020–2023 Micro-Seismicity in Enguri Area (Georgia). Geosciences 2025, 15, 247

by Luciano Telesca, Nino Tsereteli, Nazi Tugushi and Tamaz Chelidze

Geosciences 2025, 15(8), 310; https://doi.org/10.3390/geosciences15080310 - 11 Aug 2025

Abstract

There was an error in the original publication [...] Full article

(This article belongs to the Section Geophysics)

25 pages, 5810 KiB

Open AccessArticle

Pliocene Marine Bivalvia from Vale Farpado (Pombal, Portugal): Palaeoenvironmental and Palaecological Significance

by Ricardo J. Pimentel, Pedro M. Callapez, Mahima Pai, Paulo Legoinha and Pedro A. Dinis

Geosciences 2025, 15(8), 309; https://doi.org/10.3390/geosciences15080309 - 8 Aug 2025

Abstract

The western Iberian marine Pliocene represents a key transitional zone between tropical and boreal molluscan faunas. Recent studies at the rediscovered fossil locality of Vale Farpado have yielded 34 bivalve species, distributed among 18 families. The most diverse families identified are Veneridae and [...] Read more.

The western Iberian marine Pliocene represents a key transitional zone between tropical and boreal molluscan faunas. Recent studies at the rediscovered fossil locality of Vale Farpado have yielded 34 bivalve species, distributed among 18 families. The most diverse families identified are Veneridae and Pectinidae. The assemblage is predominantly composed of suspension- and deposit-feeding taxa, with no evidence of carnivorous feeding strategies. Most taxa exhibit an infaunal life habitat. Initial colonising bivalve communities inhabited mobile, gravel-dominated substrates, where coarse clasts and disarticulated bioclasts provided stable microhabitats for epifaunal species. Over time, later assemblages became established, primarily on sandy substrates. Palaeoenvironmental indicators, including molluscs and foraminifera, suggest that these benthic communities occupied the infralittoral zone, at depths generally shallower than 30 metres, and the sea surface temperatures were broadly subtropical. However, periodic incursions of cooler, nutrient-rich waters driven by upwelling systems influenced local conditions, enhancing primary productivity and supporting a taxonomically rich and ecologically complex benthic ecosystem. The bivalve assemblages of Vale Farpado thus contribute valuable insights into the palaeoecology and biogeographical dynamics of the Pliocene North Atlantic, particularly in the context of sea surface temperature gradients and bivalve faunal interchange between temperate and tropical marine realms. Full article

(This article belongs to the Section Sedimentology, Stratigraphy and Palaeontology)

► Show Figures

Figure 1

21 pages, 4201 KiB

Open AccessArticle

Short-Term Geomorphological Changes of the Sabato River (Southern Italy)

by Francesca Martucci, Floriana Angelone, Edoardo G. D’Onofrio, Filippo Russo and Paolo Magliulo

Geosciences 2025, 15(8), 308; https://doi.org/10.3390/geosciences15080308 - 8 Aug 2025

Abstract

Short-term channel adjustments are a research topic of great relevance in the framework of fluvial geomorphology, but studies on this topic have been quite scarce in Southern Italy, at least since the 2010s, notwithstanding the fact that this area is strongly representative of [...] Read more.

Short-term channel adjustments are a research topic of great relevance in the framework of fluvial geomorphology, but studies on this topic have been quite scarce in Southern Italy, at least since the 2010s, notwithstanding the fact that this area is strongly representative of a much wider morphoclimatic context, i.e., the Mediterranean area, which particularly suffers from the effects of current climate change. Currently, different interpretations still exist about the type and role of controlling factors, and a common morphoevolutionary trend is quite far from being defined; so, new case studies are needed. In this paper, the geomorphological changes experienced by the Sabato R. (Southern Italy) over a period of ~150 years were investigated. A reach-scale geomorphological analysis in a GIS environment of raster data, consisting of four topographic maps (from 1870, 1909, 1941 and 1955) and five sets of orthophotos (from 1998, 2004, 2008, 2011 and 2014), was carried out, integrated with field-surveyed data. Land-use changes, in-channel anthropic disturbances, floods and rainfall variations were selected as possible controlling factors. The study highlighted four morphoevolutionary phases of the studied river. Phase 1 (1870s–1910s) was characterized by a relative channel stability in terms of both mean width and pattern, while channel widening dominated during Phase 2 (1910s–1940s). In contrast, Phase 3 (1940s–1990s) was characterized by intense and diffuse narrowing. Finally, during Phase 4 (from the 1990s onward), an alternation in channel narrowing and flood-induced widening was detected. During all phases, changes in both channel pattern and riverbed elevation were less evident than those in channel width. Land-use changes and, later, floods, in addition to in-channel human disturbances at a local scale, were the main controlling factors. The obtained results have profound implications for rivers located outside Italy as well, as they provide new insights into the role played by the considered controlling factors in the geomorphological evolution of a typical Mediterranean river. Understanding this role is fundamental in regional-scale river management, hazard mitigation and environmental planning, as proved by the vast pre-existing scientific literature. Full article

(This article belongs to the Special Issue Integrating Geomorphological and Hydrological Insights for Flood Risk Assessment)

► Show Figures

Figure 1

28 pages, 4027 KiB

Open AccessReview

Isotopes in Archeology: Perspectives on Post-Mortem Alteration and Climate Change

by Antonio Simonetti and Michele R. Buzon

Geosciences 2025, 15(8), 307; https://doi.org/10.3390/geosciences15080307 - 7 Aug 2025

Abstract

Isotopic investigations focused on determining the mobility and provenance of ancient human civilizations and sourcing of archeological artifacts continue to gain prominence in archeology. Most studies focus on the premise that the geographic variation in isotope systems of interest (e.g., Sr, Pb, Nd, [...] Read more.

Isotopic investigations focused on determining the mobility and provenance of ancient human civilizations and sourcing of archeological artifacts continue to gain prominence in archeology. Most studies focus on the premise that the geographic variation in isotope systems of interest (e.g., Sr, Pb, Nd, O) in the natural environment is recorded in both human hard tissues of local individuals and raw materials sourced for artifacts within the same region. The introduction of multi-collection–inductively coupled plasma mass spectrometry (MC-ICP-MS) and laser ablation systems are techniques that consume smaller sample sizes compared to previous mass spectrometric approaches due to their higher ionization efficiency and increased sensitivity. This development has facilitated the isotopic measurement of trace elements present at low abundances (e.g., Pb, Nd, <1-to-low ppm range) particularly in human tooth enamel. Accurate interpretation of any isotope ratio measurement for the proveniencing of such low-abundance samples requires the adequate evaluation of post-mortem diagenetic alteration. A synopsis of practices currently in use for identifying post-mortem alteration in human archeological samples is discussed here. Post-mortem shifts in radiogenic isotope signatures resulting from secondary alteration are distinct from those potentially related to the impact of climate change on the bioavailable budgets for these elements. This topic is of interest to the archeological community and discussed here in the context of Holocene-aged samples from burial sites within the Nile River Valley System, and preferred dust source areas from the neighboring Sahara Desert. Full article

(This article belongs to the Special Issue Isotope Geochemistry: Latest Developments and Applications for Geosciences)

► Show Figures

Figure 1

23 pages, 3031 KiB

Open AccessArticle

Integrated Capuchin Search Algorithm-Optimized Multilayer Perceptron for Robust and Precise Prediction of Blast-Induced Airblast in a Blasting Mining Operation

by Kesalopa Gaopale, Takashi Sasaoka, Akihiro Hamanaka and Hideki Shimada

Geosciences 2025, 15(8), 306; https://doi.org/10.3390/geosciences15080306 - 6 Aug 2025

Abstract

Blast-induced airblast poses a significant environmental and operational issue for surface mining, affecting safety, regulatory adherence, and the well-being of surrounding communities. Despite advancements in machine learning methods for predicting airblast, present studies neglect essential geomechanical characteristics, specifically rock mass strength (RMS), which [...] Read more.

Blast-induced airblast poses a significant environmental and operational issue for surface mining, affecting safety, regulatory adherence, and the well-being of surrounding communities. Despite advancements in machine learning methods for predicting airblast, present studies neglect essential geomechanical characteristics, specifically rock mass strength (RMS), which is vital for energy transmission and pressure-wave attenuation. This paper presents a capuchin search algorithm-optimized multilayer perceptron (CapSA-MLP) that incorporates RMS, hole depth (HD), maximum charge per delay (MCPD), monitoring distance (D), total explosive mass (TEM), and number of holes (NH). Blast datasets from a granite quarry were utilized to train and test the model in comparison to benchmark approaches, such as particle swarm optimized artificial neural network (PSO-ANN), multivariate regression analysis (MVRA), and the United States Bureau of Mines (USBM) equation. CapSA-MLP outperformed PSO-ANN (RMSE = 1.120, R² = 0.904 compared to RMSE = 1.284, R² = 0.846), whereas MVRA and USBM exhibited lower accuracy. Sensitivity analysis indicated RMS as the main input factor. This study is the first to use CapSA-MLP with RMS for airblast prediction. The findings illustrate the significance of metaheuristic optimization in developing adaptable, generalizable models for various rock types, thereby improving blast design and environmental management in mining activities. Full article

(This article belongs to the Section Geomechanics)

► Show Figures

Figure 1

19 pages, 14233 KiB

Open AccessArticle

Subsurface Characterization of the Merija Anticline’s Rooting Using Integrated Geophysical Techniques: Implications for Copper Exploration

by Mohammed Boumehdi, Hicham Khebbi, Doha Dchar, Lahsen Achkouch, Anwar Ain Tagzalt, Nour Eddine Berkat, Mohammed Magoua, Youssef Hahou and Othman Sadki

Geosciences 2025, 15(8), 305; https://doi.org/10.3390/geosciences15080305 - 6 Aug 2025

Abstract

This study investigates the subsurface rooting of the Merija anticline in the Missour Basin, Morocco, with a focus on copper mineralization exploration. A sequential geophysical workflow was implemented, combining gravity surveys, electrical resistivity (ER), and induced polarization (IP) methods. The gravity data, acquired [...] Read more.

This study investigates the subsurface rooting of the Merija anticline in the Missour Basin, Morocco, with a focus on copper mineralization exploration. A sequential geophysical workflow was implemented, combining gravity surveys, electrical resistivity (ER), and induced polarization (IP) methods. The gravity data, acquired along spaced profiles extending from outcropping areas to Quaternary-covered zones, clearly delineated the structural continuity of the anticline beneath the cover. The application of trend filtering in covered areas allowed the removal of regional effects, successfully isolating residual anomalies associated with the buried continuation of the anticline. Interpolated Bouguer anomaly maps highlighted a major regional fault, interpreted as controlling the deep rooting of the anticline. A resistivity profile was then deployed perpendicular to this fault, providing detailed imaging of the anticline’s geometry and lithological contrasts. Complementary IP profiles conducted near the mine site targeted the detection of chargeability anomalies associated with copper mineralization dominated by malachite, confirming the electrical signature of copper mineralization, particularly within the sandstone and conglomerate formations of the Lower Cretaceous. To validate the geophysical interpretations, a drilling campaign was conducted, which confirmed the presence of the identified lithological units and the anticline rooting, as revealed by geophysical data. This approach provides a robust framework for copper exploration in the Merija area and can be adapted to similar geological contexts elsewhere. Full article

(This article belongs to the Section Geophysics)

► Show Figures

Figure 1

21 pages, 1212 KiB

Open AccessArticle

A Semi-Supervised Approach to Characterise Microseismic Landslide Events from Big Noisy Data

by David Murray, Lina Stankovic and Vladimir Stankovic

Geosciences 2025, 15(8), 304; https://doi.org/10.3390/geosciences15080304 - 6 Aug 2025

Abstract

Most public seismic recordings, sampled at hundreds of Hz, tend to be unlabelled, i.e., not catalogued, mainly because of the sheer volume of samples and the amount of time needed by experts to confidently label detected events. This is especially challenging for very [...] Read more.

Most public seismic recordings, sampled at hundreds of Hz, tend to be unlabelled, i.e., not catalogued, mainly because of the sheer volume of samples and the amount of time needed by experts to confidently label detected events. This is especially challenging for very low signal-to-noise ratio microseismic events that characterise landslides during rock and soil mass displacement. Whilst numerous supervised machine learning models have been proposed to classify landslide events, they rely on a large amount of labelled datasets. Therefore, there is an urgent need to develop tools to effectively automate the data-labelling process from a small set of labelled samples. In this paper, we propose a semi-supervised method for labelling of signals recorded by seismometers that can reduce the time and expertise needed to create fully annotated datasets. The proposed Siamese network approach learns best class-exemplar anchors, leveraging learned similarity between these anchor embeddings and unlabelled signals. Classification is performed via soft-labelling and thresholding instead of hard class boundaries. Furthermore, network output explainability is used to explain misclassifications and we demonstrate the effect of anchors on performance, via ablation studies. The proposed approach classifies four landslide classes, namely earthquakes, micro-quakes, rockfall and anthropogenic noise, demonstrating good agreement with manually detected events while requiring few training data to be effective, hence reducing the time needed for labelling and updating models. Full article

(This article belongs to the Special Issue Integrated Approaches with Seismic Techniques to Investigate Landslide Areas)

► Show Figures

Figure 1

14 pages, 7406 KiB

Open AccessArticle

Machine Learning-Driven Calibration of MODFLOW Models: Comparing Random Forest and XGBoost Approaches

by Husam Musa Baalousha

Geosciences 2025, 15(8), 303; https://doi.org/10.3390/geosciences15080303 - 5 Aug 2025

Abstract

The groundwater inverse problem has several challenges such as instability, non-uniqueness, and complexity, especially for heterogeneous aquifers. Solving the inverse problem is the traditional way to calibrate models, but it is both time-consuming and sensitive to errors in the measurements. This study explores [...] Read more.

The groundwater inverse problem has several challenges such as instability, non-uniqueness, and complexity, especially for heterogeneous aquifers. Solving the inverse problem is the traditional way to calibrate models, but it is both time-consuming and sensitive to errors in the measurements. This study explores the use of machine learning (ML) surrogate models, namely Random Forest (RF) and Extreme Gradient Boosting (XGBoost), to solve the inverse problem for the groundwater model calibration. Datasets for 20 hydraulic conductivity fields were created randomly based on statistics of hydraulic conductivity from the available data of the Northern Aquifer of Qatar, which was used as a case study. The corresponding hydraulic head values were obtained using MODFLOW simulations, and the data were used to train and validate the ML models. The trained surrogate models were used to estimate the hydraulic conductivity based on field observations. The results show that both RF and XGBoost have considerable predictive skill, with RF having better R² and RMSE values (R² = 0.99 for training, 0.93 for testing) than XGBoost (R² = 0.86 for training, 0.85 for testing). The ML-based method lowered the computational effort greatly compared to the classical solution of the inverse problem (i.e., using PEST) and still produced strong and reliable spatial patterns of hydraulic conductivity. This demonstrates the potential of machine learning models for calibrating complex groundwater systems. Full article

(This article belongs to the Section Hydrogeology)

► Show Figures

Graphical abstract

19 pages, 6218 KiB

Open AccessArticle

Quantitative Relationship Between Electrical Resistivity and Water Content in Unsaturated Loess: Theoretical Model and ERT Imaging Verification

by Hu Zeng, Qianli Zhang, Cui Du, Jie Liu and Yilin Li

Geosciences 2025, 15(8), 302; https://doi.org/10.3390/geosciences15080302 - 5 Aug 2025

Abstract

As a typical porous medium, unsaturated loess demonstrates critical hydro-mechanical coupling properties that fundamentally influence geohazard mitigation, groundwater resource evaluation, and foundation stability in geotechnical engineering. This investigation develops a novel theoretical framework to overcome the limitations of existing models in converting electrical [...] Read more.

As a typical porous medium, unsaturated loess demonstrates critical hydro-mechanical coupling properties that fundamentally influence geohazard mitigation, groundwater resource evaluation, and foundation stability in geotechnical engineering. This investigation develops a novel theoretical framework to overcome the limitations of existing models in converting electrical resistivity tomography (ERT) profiles into water content distributions for unsaturated loess through quantitative inversion modeling. Systematic laboratory investigations on remolded loess specimens with controlled density and water content conditions revealed distinct resistivity–water interaction mechanisms. A characteristic two-stage decay pattern was identified: resistivity exhibited an exponential decrease from 420 Ω·m (water saturation (S_w = 10%)) to 90 Ω·m (S_w = 40%), followed by asymptotic stabilization at S_w ≥ 40%. The derived quantitative correlation provides a robust mathematical basis for water content profile inversion. Field validation through integrated ERT and borehole data demonstrated exceptional predictive accuracy in shallow strata (<20 m depth), achieving mean absolute errors of <5%. However, inversion reliability decreased with depth (>20 m), primarily attributed to density-dependent charge transport mechanisms. This underscores the necessity of incorporating coupled thermo-hydro-mechanical processes for deep-layer characterization. This study provides a robust framework for engineering applications of ERT in loess terrains, offering significant advancements in geotechnical monitoring and geohazard prevention. Full article

(This article belongs to the Topic Transport, Transformation and Cycling of Elements in Water and Soil and Their Response to Human Activities)

► Show Figures

Figure 1

58 pages, 10593 KiB

Open AccessFeature PaperArticle

Statistical Physics of Fissure Swarms and Dike Swarms

by Agust Gudmundsson

Geosciences 2025, 15(8), 301; https://doi.org/10.3390/geosciences15080301 - 4 Aug 2025

Abstract

Fissure swarms and dike swarms in Iceland constitute the main parts of volcanic systems that are 40–150 km long, 5–20 km wide, extend to depths of 10–20 km, and contain 2 × 10¹⁴ outcrop-scale (≥0.1 m) and 10^22–23 down to grain-scale [...] Read more.

Fissure swarms and dike swarms in Iceland constitute the main parts of volcanic systems that are 40–150 km long, 5–20 km wide, extend to depths of 10–20 km, and contain 2 × 10¹⁴ outcrop-scale (≥0.1 m) and 10^22–23 down to grain-scale (≥1 mm) fractures, suggesting that statistical physics is an appropriate method of analysis. Length-size distributions of 565 outcrop-scale Holocene fissures (tension fractures and normal faults) and 1041 Neogene dikes show good to excellent fits with negative power laws and exponential laws. Here, the Helmholtz free energy is used to represent the energy supplied to the swarms and to derive the Gibbs–Shannon entropy formula. The calculated entropies of 12 sets and subsets of fissures and 3 sets and subsets of dikes all show strong positive correlations with sets/subsets length ranges and scaling exponents. Statistical physics considerations suggest that, at a given time, the probability of the overall state of stress in a crustal segment being heterogeneous is much greater than the state of stress being homogeneous and favourable to the propagation of a fissure or a dike. In a heterogeneous stress field, most fissures/dikes become arrested after a short propagation—which is a formal explanation of the observed statistical size-length distributions. As the size of the stress-homogenised rock volume increases larger fissures/dikes can form, increasing the length range of the distribution (and its entropy) which may, potentially, transform from an exponential distribution into a power-law distribution. Full article

► Show Figures

Figure 1

29 pages, 12422 KiB

Open AccessArticle

Real-Time Foreshock–Aftershock–Swarm Discrimination During the 2025 Seismic Crisis near Santorini Volcano, Greece: Earthquake Statistics and Complex Networks

by Ioanna Triantafyllou, Gerassimos A. Papadopoulos, Constantinos Siettos and Konstantinos Spiliotis

Geosciences 2025, 15(8), 300; https://doi.org/10.3390/geosciences15080300 - 4 Aug 2025

Abstract

The advanced determination of the type (foreshock–aftershock–swarm) of an ongoing seismic cluster is quite challenging; only retrospective solutions have thus far been proposed. In the period of January–March 2025, a seismic cluster, recorded between Santorini volcano and Amorgos Island, South Aegean Sea, caused [...] Read more.

The advanced determination of the type (foreshock–aftershock–swarm) of an ongoing seismic cluster is quite challenging; only retrospective solutions have thus far been proposed. In the period of January–March 2025, a seismic cluster, recorded between Santorini volcano and Amorgos Island, South Aegean Sea, caused considerable social concern. A rapid increase in both the seismicity rate and the earthquake magnitudes was noted until the mainshock of M_L = 5.3 on 10 February; afterwards, activity gradually diminished. Fault-plane solutions indicated SW-NE normal faulting. The epicenters moved with a mean velocity of ~0.72 km/day from SW to NE up to the mainshock area at a distance of ~25 km. Crucial questions publicly emerged during the cluster. Was it a foreshock–aftershock activity or a swarm of possibly volcanic origin? We performed real-time discrimination of the cluster type based on a daily re-evaluation of the space–time–magnitude changes and their significance relative to background seismicity using earthquake statistics and the topological metric betweenness centrality. Our findings were periodically documented during the ongoing cluster starting from the fourth cluster day (2 February 2025), at which point we determined that it was a foreshock and not a case of seismic swarm. The third day after the M_L = 5.3 mainshock, a typical aftershock decay was detected. The observed foreshock properties favored a cascade mechanism, likely facilitated by non-volcanic material softening and the likely subdiffusion processes in a dense fault network. This mechanism was possibly combined with an aseismic nucleation process if transient geodetic deformation was present. No significant aftershock expansion towards the NE was noted, possibly due to the presence of a geometrical fault barrier east of the Anydros Ridge. The 2025 activity offered an excellent opportunity to investigate deciphering the type of ongoing seismicity cluster for real-time discrimination between foreshocks, aftershocks, and swarms. Full article

(This article belongs to the Special Issue Editorial Board Members' Collection Series: Natural Hazards)

► Show Figures

Figure 1

16 pages, 21475 KiB

Open AccessArticle

Palynostratigraphy of the “Muschelkalk Sedimentary Cycle” in the NW Iberian Range, Central Spain

by Manuel García-Ávila, Soledad García-Gil and José B. Diez

Geosciences 2025, 15(8), 299; https://doi.org/10.3390/geosciences15080299 - 4 Aug 2025

Abstract

The Muschelkalk sedimentary cycle in the northwestern region of the Iberian Range (central Spain) lies within a transitional area between the Iberian and Hesperia type Triassic domains. To improve the understanding of its paleopalynological record, fifty samples were analyzed from ten stratigraphic sections [...] Read more.

The Muschelkalk sedimentary cycle in the northwestern region of the Iberian Range (central Spain) lies within a transitional area between the Iberian and Hesperia type Triassic domains. To improve the understanding of its paleopalynological record, fifty samples were analyzed from ten stratigraphic sections corresponding to the Tramacastilla Dolostones Formation (TD Fm.), Cuesta del Castillo Sandstones and Siltstones Formation (CCSS Fm.), and Royuela Dolostones, Marls and Limestones Formation (RDML Fm.). Despite previous studies in the area, palynological data remain scarce or insufficiently detailed, highlighting the need for a systematic reassessment. Based on the identified palynological assemblages, the succession is assigned to an age spanning from the Fassanian to the Longobardian, with a possible extension into the base of the Julian (early Carnian). The results confirm that the siliciclastic unit (CCSS) represents a lateral facies change with respect to the carbonate formations of the upper Muschelkalk (TD and RDML). From a paleoecological perspective, the assemblages indicate a warm and predominantly dry environment, dominated by xerophytic conifers, although evidence of more humid local environments, such as marshes or coastal plains, is also observed. Full article

(This article belongs to the Section Sedimentology, Stratigraphy and Palaeontology)

► Show Figures

Figure 1

21 pages, 4289 KiB

Open AccessArticle

H₂ Transport in Sedimentary Basin

by Luisa Nicoletti, Juan Carlos Hidalgo, Dariusz Strąpoć and Isabelle Moretti

Geosciences 2025, 15(8), 298; https://doi.org/10.3390/geosciences15080298 - 3 Aug 2025

Abstract

Natural hydrogen is generated by fairly deep processes and/or in low-permeability rocks. In such contexts, fluids circulate mainly through the network of faults and fractures. However, hydrogen flows from these hydrogen-generating layers can reach sedimentary rocks with more typical permeability and porosity, allowing [...] Read more.

Natural hydrogen is generated by fairly deep processes and/or in low-permeability rocks. In such contexts, fluids circulate mainly through the network of faults and fractures. However, hydrogen flows from these hydrogen-generating layers can reach sedimentary rocks with more typical permeability and porosity, allowing H₂ flows to spread out rather than be concentrated in fractures. In that case, three different H₂ transport modes exist: advection (displacement of water carrying dissolved gas), diffusion, and free gas Darcy flow. Numerical models have been run to compare the efficiency of these different modes and the pathway they imply for the H₂ in a sedimentary basin with active aquifers. The results show the key roles of these aquifers but also the competition between free gas flow and the dissolved gas displacement which can go in opposite directions. Even with a conservative hypothesis on the H₂ charge, a gaseous phase exists at few kilometers deep as well as free gas accumulation. Gaseous phase displacement could be the faster and diffusion is neglectable. The modeling also allows us to predict where H₂ is expected in the soil: in fault zones, eventually above accumulations, and, more likely, due to exsolution, above shallow aquifers. Full article

(This article belongs to the Special Issue Circular Economy in Energy Extraction: Geological Insights and Innovations)

► Show Figures

Figure 1

Journal Description

Geosciences

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI