Geosciences

17 pages, 9255 KiB

Open AccessArticle

Forward Modeling Simulations to Validate Changes in Electrical Resistivity Tomography Monitoring Data for a Slope with Complex Geology

by Azadeh Hojat, Luigi Zanzi, Greta Tresoldi and Meng Heng Loke

Geosciences 2025, 15(1), 33; https://doi.org/10.3390/geosciences15010033 - 20 Jan 2025

Viewed by 579

Abstract

The electrical resistivity tomography (ERT) method has been increasingly integrated with hydrogeological risk mitigation strategies to monitor the internal conditions and the stability of natural and artificial slopes. In this paper, we discuss a case study in which numerical simulations were essential to [...] Read more.

The electrical resistivity tomography (ERT) method has been increasingly integrated with hydrogeological risk mitigation strategies to monitor the internal conditions and the stability of natural and artificial slopes. In this paper, we discuss a case study in which numerical simulations were essential to validate the interpretation of the resistivity images obtained from an ERT monitoring system installed on a critical slope in Italy. An initial analysis of the monitoring data after rainfall events in the study site showed that the resistivity values were decreased only in the central zone along the ERT line, but they were increased in the two sides of the profile. Opposite behaviors were observed during the drying processes following the rainfall events. Core samples show complex geology at the study site, which might justify uneven responses of the different subsurface bodies to meteorological events. However, we decided to investigate the possible inversion artifacts resulting from the individual inversion of the tomographic sections. Forward modeling simulations on simplified time-lapse models of the study site were performed to explore this problem and to compare the individual and time-lapse inversions. Synthetic tests confirmed the nature of these unexpected behaviors and assessed the absolute necessity of a time-lapse approach for a correct inversion of monitoring data in the presence of a complex geological model such as the one of this case study. By applying the time-lapse inversion approach to the real data, the inversion artifact problem was substantially solved, arriving after the proper calibration of the inversion parameters, mainly the time-lapse damping factor and the spatial and temporal roughness constraints, to a reduction in the inversion artifacts to less than 5%. Full article

(This article belongs to the Section Geophysics)

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24 pages, 13958 KiB

Open AccessArticle

Mapping of Agate-like Soil Cover Structures Based on a Multitemporal Soil Line Using Neural Network Filtering of Remote Sensing Data

by Dmitry I. Rukhovich, Polina V. Koroleva, Alexey D. Rukhovich and Mikhail A. Komissarov

Geosciences 2025, 15(1), 32; https://doi.org/10.3390/geosciences15010032 - 16 Jan 2025

Viewed by 456

Abstract

The present study focuses on analysis of the soil cover structure (SCS, SCSs), which is the most detailed level of soil organization in space. The detail in which complex SCS can be studied is often insufficient, since until now it has not been [...] Read more.

The present study focuses on analysis of the soil cover structure (SCS, SCSs), which is the most detailed level of soil organization in space. The detail in which complex SCS can be studied is often insufficient, since until now it has not been possible to map it over large areas at scales larger than 1:10,000. To increase the detail in which SCS can be studied, the methods of identifying the bare soil surface (BSS) and averaging its multitemporal spectral characteristics were used, which opens up new possibilities for mapping complex SCS over large areas. New SCSs of leached chernozems (Luvic Chernic Phaeozem) were discovered, which can produce patterns on satellite images similar to sections of Timan agate—agate-like soil cover structures (ASCS, ASCSs). ASCSs are formed on Quaternary sediments of varying thickness from 0.3 to 6 m, underlain by carbonate and red sediments of the Permian period. The ASCS pattern is formed by ring-shaped stripes (rings) of different colors and brightness, which are determined by the carbonate and red-colored inclusions involved in the arable horizon. Eight soil varieties were identified to describe ASCSs during the study. According to the WRB, there are six main soil types, and according to the classification of Russian soils in 1977, there are four types. ASCSs were identified over large areas and soil maps of ASCSs were constructed using multitemporal spectral characteristics of the BSS in the form of multitemporal soil line coefficients. Neural networks were used to identify BSS on big remote sensing data. ASCSs have contrasting soil properties and contrasting fertility (productivity of agricultural crops). ASCS maps can serve as the basis for task maps of precision farming systems. Perhaps ASCSs are unique objects for the area of chernozem distribution, where in one soil profile there are rocks with an age from the first thousand years (Quaternary) to 250 million years (Permian). Chernozems are fertile, studied, mercilessly exploited, but sometimes they are simply beautiful—agate-like. Full article

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27 pages, 6768 KiB

Open AccessArticle

Complex Study of Settlements Dating from the Paleolithic to Medieval Period in the Ural Mountains on the Border of Europe and Asia

by Valentina Prikhodko, Nikita Savelev, Vyacheslav Kotov, Sergey Nikolaev, Evgeny Ruslanov, Mikhail Rumyantsev and Elena Manakhova

Geosciences 2025, 15(1), 31; https://doi.org/10.3390/geosciences15010031 - 16 Jan 2025

Viewed by 471

Abstract

Soil, geochemical, microbiological, and archeological studies were conducted at eight settlements dating from the Paleolithic to Late Medieval and Modern Ages near the southern Trans-Urals Mountains, Russia. The forest-steppe landscapes, rivers, and abundant mineral resources have attracted people to the region since ancient [...] Read more.

Soil, geochemical, microbiological, and archeological studies were conducted at eight settlements dating from the Paleolithic to Late Medieval and Modern Ages near the southern Trans-Urals Mountains, Russia. The forest-steppe landscapes, rivers, and abundant mineral resources have attracted people to the region since ancient times. Cultural layers (CLs) are marked by finds of ceramics fragments, animal bones, stone, and metal tools. The properties of CLs include close-to-neutral pH, being well structured, the absence of salinity, enrichment with exchangeable calcium, and anthropogenic phosphorus (0.2–0.4%). The majority of CLs start at a depth of 3–25 cm, extend to 40–60 cm, and contain 6–10% organic carbon (Corg) in the 0–20 cm layer, reflecting carbon input from modern-day processes. At the Ishkulovo site (0.6–0.8 ka BP), Corg decreases to 1.3% because the CL is below 80 cm, and in the absence of fresh organic material input, carbon has been mineralized. The proximity of sites to deposits of copper, chromium, zinc, and manganese in the Ural Mountains creates natural high-content anomalies in the region, as indicated by their abundance in soils and parent rocks. In the past, these elements were also released into CLs from metal products, ceramic fragments, and raw materials used in their manufacture. The sites are quite far (18–60 km) from the Magnitogorsk Metallurgical plant, but industrial stockpiles of S (technogenic coefficient—Ct 30–87%), and, less often, Cr, Mn, and Sr (Ct 30–40%) accumulated in surface layers. These three factors have led to the concentration of pollutants of the first (arsenic, chromium, lead, and zinc) and second (cobalt, copper, and nickel) hazard classes at CLs, often in quantities 2–5 times higher than values for parent materials and geosphere average content (“Clarke” value), and, and less often, more than the allowable content for human health. This may have influenced their health and behavioral functions. Due to the above properties, chernozems have a high buffering capacity and a strong bond with heavy metals. Therefore, no inhibition of microbes was observed. The microbial biomass of the 0–10 cm layer is high, 520–680 µg C/g, and microbes cause the emission of 1.0 C-CO₂ µg/g of soil per hour. During the ancient settlements’ development, a favorable paleoclimate was noted based on the data cited. This contributed to the spread of productive paleolandscapes, ensuring the development of domestic cattle breeding and agriculture. Full article

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23 pages, 2271 KiB

Open AccessArticle

Estimation of Radon Flux Density Changes in Temporal Vicinity of the Shipunskoe Earthquake with M_w = 7.0, 17 August 2024 with the Use of the Hereditary Mathematical Model

by Dmitrii Tverdyi, Evgeny Makarov and Roman Parovik

Geosciences 2025, 15(1), 30; https://doi.org/10.3390/geosciences15010030 - 16 Jan 2025

Viewed by 492

Abstract

Using the data of radon accumulation in a chamber with excess volume at one of the points of the Kamchatka subsurface gas-monitoring network, the change in radon flux density due to seismic waves and post-seismic relaxation of the medium is shown. A linear [...] Read more.

Using the data of radon accumulation in a chamber with excess volume at one of the points of the Kamchatka subsurface gas-monitoring network, the change in radon flux density due to seismic waves and post-seismic relaxation of the medium is shown. A linear fractional equation is considered to be a model equation. The change of radon-transport intensity due to changes in the state of the geo-environment is described by a fractional Gerasimov–Caputo derivative of constant order. Presumably, the order of the fractional derivative is related to the radon-transport intensity in the geosphere. Using the Levenberg–Marquardt method, the optimal values of the model parameters were determined based on experimental data: air exchange coefficient and order of fractional derivative, which allowed the solving of the problems of radon flux density determination. Data in the temporal neighborhood of a strong earthquake with

M_{w} = 7.0

, which occurred in the northern part of Avacha Bay on 17 August 2024, were used. As a result of the modeling, it is shown that the strong seismic impact and subsequent processes led to changes in the radon flux in the accumulation chamber. The obtained model curves agree well with the real data, and the obtained estimates of radon flux density agree with the theory. Full article

(This article belongs to the Section Natural Hazards)

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32 pages, 33452 KiB

Open AccessArticle

Geomorphological Observations and Physical Hypotheses About Martian Dune Gullies

by Adriano Nardi and Antonio Piersanti

Geosciences 2025, 15(1), 29; https://doi.org/10.3390/geosciences15010029 - 16 Jan 2025

Viewed by 569

Abstract

We propose the hypothesis that dune gullies and seasonal “meteorological” appearances observed on the same dunes (e.g., frosting) may have a common origin. These gullies are difficult to explain through the action of liquid flow. The occurrence of a spring flowing from the [...] Read more.

We propose the hypothesis that dune gullies and seasonal “meteorological” appearances observed on the same dunes (e.g., frosting) may have a common origin. These gullies are difficult to explain through the action of liquid flow. The occurrence of a spring flowing from the crest of a dune seems impossible to explain. However, these phenomena could originate from the impact of wind on the profiles of some large Martian dunes. This aerodynamic effect could seasonally generate all the meteorological phenomena we observe on these dunes (bodies of ice, frost, moisture trails, and vapor clouds) and as a result, produce gullies with a peculiar morphology different from the standard. Thus, dune gullies could originate from meteorological liquids, but through a process unlike those known on Earth. Evidence from the Kaiser, Russell, and Korolev Craters supports the possibility of a partial water cycle (a half-cycle), potentially the remnant of a complete ancient cycle. Full article

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30 pages, 6425 KiB

Open AccessArticle

Global Sn Isotope Compositions of Cassiterite Identify the Magmatic–Hydrothermal Evolution of Tin Ore Systems

by Ryan Mathur, Wayne Powell, Junming Yao, Frederico Guimaraes, Yanbo Cheng, Linda Godfrey, Fernando Tornos, David Killick, Jay Stephens, Jingwen Mao, Mingguang Sun and Bernd Lehmann

Geosciences 2025, 15(1), 28; https://doi.org/10.3390/geosciences15010028 - 15 Jan 2025

Viewed by 488

Abstract

Published Sn isotope data along with 150 new analyses of cassiterite and four granite analyses constrain two major tin isotope fractionation steps associated with (1) separation of tin from the magma/orthomagmatic transitional environment and (2) hydrothermal activity. A distinct Sn isotope difference across [...] Read more.

Published Sn isotope data along with 150 new analyses of cassiterite and four granite analyses constrain two major tin isotope fractionation steps associated with (1) separation of tin from the magma/orthomagmatic transitional environment and (2) hydrothermal activity. A distinct Sn isotope difference across deposit type, geological host rocks, and time of ore deposit formation demonstrates that the difference in the mean δ¹²⁴Sn value represents the operation of a unified process. The lower Sn isotope values present in both residual igneous rocks and pegmatite suggest that heavier Sn isotopes were extracted from the system during orthomagmatic fluid separation, likely by F ligands with Sn. Rayleigh distillation models this first F ligand-induced fractionation. The subsequent development of the hydrothermal system is characterized by heavier Sn isotope composition proximal to the intrusion, which persists in spite of Sn isotope fractionating towards isotopically lighter Sn during hydrothermal evolution. Full article

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

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22 pages, 40492 KiB

Open AccessArticle

Sulfosalts and Sulfates in the Epithermal Au-Ag-Te Emmy Deposit (Khabarovsk Territory, Far East of Russia): Implications for the Mineralization Process

by Tamara Yu. Yakich, Panagiotis Voudouris, Darya V. Levochskaia, Alexey K. Mazurov, Mikhail V. Shaldybin, Yuriy M. Lopushnyak, Alexey S. Ruban, Evan Dasi, Prokopiy N. Maximov, Ekaterina A. Sinkina, Ksenia V. Bestemianova and Maxim A. Rudmin

Geosciences 2025, 15(1), 26; https://doi.org/10.3390/geosciences15010026 - 14 Jan 2025

Viewed by 515

Abstract

This study considers the features of the chemical composition, internal structure, and oscillatory zoning of sulfosalts and sulfates in the epithermal high–intermediate-sulfidation-type Au-Ag-Te Emmy deposit (Khabarovsk Territory, Russia). In Emmy deposit, sulfosalts primarily represent goldfieldite, probably corresponding to a high-sulfidation (HS) mineral association [...] Read more.

This study considers the features of the chemical composition, internal structure, and oscillatory zoning of sulfosalts and sulfates in the epithermal high–intermediate-sulfidation-type Au-Ag-Te Emmy deposit (Khabarovsk Territory, Russia). In Emmy deposit, sulfosalts primarily represent goldfieldite, probably corresponding to a high-sulfidation (HS) mineral association replaced bytennantite–tetrahedrite group minerals. The latter is associated with tellurides and native tellurium, corresponding to an intermediate-sulfidation (IS)-type ore assemblage and suggesting an increasing influx of Te, Sb, and As in the system. Goldfieldite is replaced by native tellurium and tellurides along its growth zones, and is characterized by oscillatory zoning. The replacement of goldfieldite by mercury, nickel, lead, and copper tellurides indicate a new influx of native gold, native tellurium, and gold–silver tellurides into the open mineral-forming system. At deeper levels of the Emmy deposit, an advanced argillic alteration assemblage includes aluminum phosphate–sulfate (APS) minerals, represented by members of the svanbergite–woodhouseite series. Element mapping of the studied APS mineral grains indicated three distinct areas recording the evolution of the hydrothermal system in the Emmy: an oscillatory-zoned margin enriched in sulfur, lead, and barium, corresponding to the late influx of IS state fluids related to gold and tellurides; an intermediate part, which is leached and corresponds to the HS mineralization stage; and the central part of the grains, which is enriched in cerium, calcium, and strontium, resulting from a replacement of magmatic apatite in the pre-ore alteration stage. The leached zone between the core and rim of the APS grains is related to a change in crystallization conditions, possibly due to the mixing processes of the fluids with meteoric water. Barite, found in the upper level of the advanced argillic hypogene alteration assemblage, is also characterized by oscillatory zoning, associated with the enrichment of individual zones in lead. Micron gold particles associated with barite are confined to their lead-enriched zones. The study of fluid inclusions in quartz within the Emmy deposit showed the hydrothermal ore process at a temperature of 236–337 °C. Homogenization temperatures for quartz–pyrite–goldfieldite mineral association vary within 337–310 °C and salinity varies within 0–0.18 wt.%NaCl equivalent, and for gold–silver–telluride–polymetallic mineral association, they decrease and vary within 275–236 °C and salinity slightly increases from 0.18 to 0.35 wt.%NaCl equivalent. This study demonstrates that the nature of oscillatory zoning in sulfosalts and sulfates in the Emmy deposit results from an external process. Such a process is of fundamental importance from a genetic point of view. Full article

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27 pages, 27726 KiB

Open AccessReview

Crustal and Upper Mantle Structure of the Assam Valley Region, NE India: A Review of Geophysical Findings

by Ilya Lozovsky, Ivan Varentsov and Devesh Walia

Geosciences 2025, 15(1), 27; https://doi.org/10.3390/geosciences15010027 - 12 Jan 2025

Viewed by 521

Abstract

The northeastern region of India is one of the six most seismically active convergent plate tectonic areas in the world. The north–south convergence along the Indo-Tibetan Himalayan Ranges and the east–west subduction within the Indo-Burma Ranges create a complex stress regime, resulting in [...] Read more.

The northeastern region of India is one of the six most seismically active convergent plate tectonic areas in the world. The north–south convergence along the Indo-Tibetan Himalayan Ranges and the east–west subduction within the Indo-Burma Ranges create a complex stress regime, resulting in significant seismic activity and a history of great/large earthquakes. The region’s intricate strain patterns, active faults, and potential seismic gaps underscore the need for detailed subsurface studies to effectively assess seismic hazards and impending seismicity. Geophysical research is essential for understanding the region’s geodynamic evolution, seismotectonics, and mineral resources. This manuscript reviews the geological and tectonic settings of the region and summarizes recent geophysical studies, including seismic, gravity, magnetic, and magnetotelluric surveys conducted in the Assam Valley and adjacent areas (within latitudes 24.5–28.5° N and longitudes 89–97.5° E). The review highlights key findings on hydrocarbon-bearing sediments, the configuration of the crystalline basement, the heterogeneous structures of the crust and upper mantle, and seismic discontinuities. By synthesizing these results, the review aims to enhance the understanding of seismic hazards in Northeast India, guide mitigation strategies, and identify key knowledge gaps to direct future research efforts. Full article

(This article belongs to the Section Geophysics)

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29 pages, 7626 KiB

Open AccessArticle

First Geoarchaeological and Archaeometric Investigation at the Lucanian (4th–3rd Century BCE) Site of Laurelli (Cilento, Vallo di Diano and Alburni UNESCO Global Geopark—Southern Italy)

by Ettore Valente, Antonia Serritella, Maria Luigia Rizzo, Michele Scafuro, Carlo Scirocco, Domenico Guida, Mario Valiante, Chiara Comegna, Giuseppina Balassone, Alberto De Bonis, Celestino Grifa and Elda Russo Ermolli

Geosciences 2025, 15(1), 25; https://doi.org/10.3390/geosciences15010025 - 12 Jan 2025

Viewed by 780

Abstract

The Lucanian site of Laurelli represents one of the largest, still poorly investigated, pre-Roman archaeological sites of the Cilento, Vallo di Diano and Alburni Geopark (southern Italy). The site lies on a large, low-relief surface in the upper portion of the Serrapotamo River [...] Read more.

The Lucanian site of Laurelli represents one of the largest, still poorly investigated, pre-Roman archaeological sites of the Cilento, Vallo di Diano and Alburni Geopark (southern Italy). The site lies on a large, low-relief surface in the upper portion of the Serrapotamo River basin, a right tributary of the Bussento River. Geomorphological, stratigraphical, archaeobotanical and archaeometric analyses were carried out to understand the following: (1) the choice to settle at the site of the town of Laurelli; (2) the origin of the raw material used to build the town; (3) the vegetation present during the lifetime of the town; and (4) the causes of its abandonment. The results indicate that the site was chosen because it was almost stable from a geomorphological point of view, not being affected by deep landslides. Further investigations are needed to unravel the possible occurrence of flooding as a causative event for the abandonment of Laurelli. Carpinus was widespread and used as a fuel for iron production, but the areas from which the iron was extracted have not yet been discovered. The multidisciplinary approach adopted is suitable for application in other archaeological areas worldwide. Full article

(This article belongs to the Section Geoheritage, Geoparks and Geotourism)

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23 pages, 10566 KiB

Open AccessArticle

Coupling Driving Force–Pressure–State–Impact–Response–Management Framework with Hydrochemical Data for Groundwater Management on Sithonia Peninsula, Greece

by Eleni Parastatidou, Maria Margarita Ntona, Nerantzis Kazakis and Fotios-Konstantinos Pliakas

Geosciences 2025, 15(1), 24; https://doi.org/10.3390/geosciences15010024 - 11 Jan 2025

Viewed by 1024

Abstract

Water scarcity in coastal tourist areas constitutes a critical environmental and socioeconomic sustainability issue. Hence, it is crucial to implement an integrated water resource management and protection plan. In this research, the DPSIR framework is coupled with hydrochemical data on groundwater resources in [...] Read more.

Water scarcity in coastal tourist areas constitutes a critical environmental and socioeconomic sustainability issue. Hence, it is crucial to implement an integrated water resource management and protection plan. In this research, the DPSIR framework is coupled with hydrochemical data on groundwater resources in the fractured aquifer of the Sithonia Peninsula in Chalkidiki, North Greece. Geographical and demographic data, together with morphology, geology, hydrology, and groundwater quality data, were collected and evaluated to categorize the hydrosystem’s driving forces, pressures, states, impacts, and responses. The main pressures that affect groundwater quality in the study area are tourism, geological formation, and land use. Based on the analysis of the DPSIR framework, the absence of a landfill site, the inadequate operation of sewage treatment plants and biological wastewater treatment systems, and tourist activity contribute significantly to the degradation of groundwater quality. Additionally, the fractured rock aquifer develops preferential flow paths to pollutants through preexisting faults, which influence groundwater quality. The hydrochemical analysis of groundwater indicates seawater intrusion in the coastal area. The combination of DPSIR analysis and a water quality index based on ion ratios of groundwater samples identifies high-risk areas of seawater intrusion. Thus, it is essential to reinforce groundwater resources by implementing managed aquifer recharge, limiting unnecessary use of groundwater during the tourist season, and storing surface water during the wet period. Full article

(This article belongs to the Section Hydrogeology)

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15 pages, 2396 KiB

Open AccessArticle

Regularities of Plastic Deformation Zone Formation Around Unsupported Shafts in Tectonically Disturbed Massive Rock

by Petr A. Demenkov and Ekaterina L. Romanova

Geosciences 2025, 15(1), 23; https://doi.org/10.3390/geosciences15010023 - 10 Jan 2025

Viewed by 496

Abstract

In the presented paper, an approach to assessing the size of the plastic deformation zone around a circular cavity intersecting a crushed disintegrated layer in tectonically stressed massive rock is suggested. Fractured rock zones of different quality and spatial configurations are investigated in [...] Read more.

In the presented paper, an approach to assessing the size of the plastic deformation zone around a circular cavity intersecting a crushed disintegrated layer in tectonically stressed massive rock is suggested. Fractured rock zones of different quality and spatial configurations are investigated in order to predict the size of dangerous plastic deformation zones or zones of potential rock collapses. The analysis is performed by means of numerical modeling after preliminary verification of the model by in situ and monitoring data. The paper explores the impact of such parameters of the fractured rock zone as the GSI index, the true thickness of the zone, and its inclination angle relative to the plane perpendicular to the axis of the excavation. It was found that with the increase in the thickness and angle of inclination of the fractured rock zone, the size of the hazardous zone in the vicinity of the excavation increases, while with the increase in its strength characteristics, the size of the potential failure zone decreases. According to the results of the study, qualitative dependencies are established, which localize and predict the size of the danger zone, or the potential failure zone in the vicinity of an unfixed excavation. Full article

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16 pages, 5768 KiB

Open AccessArticle

On the Ionosphere–Atmosphere–Lithosphere Coupling During the 9 November 2022 Italian Earthquake

by Mirko Piersanti, Giulia D’Angelo, Dario Recchiuti, Fabio Lepreti, Paola Cusano, Enza De Lauro, Vincenzo Carbone, Pietro Ubertini and Mariarosaria Falanga

Geosciences 2025, 15(1), 22; https://doi.org/10.3390/geosciences15010022 - 10 Jan 2025

Viewed by 519

Abstract

In the last decades, the scientific community has been focused on searching earthquake signatures in the Earth’s atmosphere, ionosphere, and magnetosphere. This work investigates an offshore Mw 5.5 earthquake that struck off the Marche region’s coast (Italy) on 9 November 2022, with a [...] Read more.

In the last decades, the scientific community has been focused on searching earthquake signatures in the Earth’s atmosphere, ionosphere, and magnetosphere. This work investigates an offshore Mw 5.5 earthquake that struck off the Marche region’s coast (Italy) on 9 November 2022, with a focus on the potential coupling between the Earth’s lithosphere, atmosphere, and magnetosphere triggered by the seismic event. Analysis of atmospheric temperature data from ERA5 reveals a significant increase in potential energy (Ep) at the earthquake’s epicenter, consistent with the generation of Atmospheric Gravity Waves (AGWs). This finding is further corroborated by the MILC analytical model, which accurately simulates the observed Ep trends (within 5%), supporting the theory of Lithosphere–Atmosphere–Ionosphere–Magnetosphere coupling. The study also examines the vertical Total Electron Content (vTEC) and finds notable fluctuations at the epicenter, exhibiting periodicities (7–12 min) characteristic of AGWs and traveling ionospheric disturbances. The correlation between ERA5 observations and MILC model predictions, particularly in temperature deviations and Ep distributions, strengthens the hypothesis that earthquake-generated AGWs impact atmospheric conditions at high altitudes, leading to observable ionospheric perturbations. This research contributes to a deeper understanding of Lithosphere–Atmosphere–Ionosphere–Magnetosphere coupling mechanisms and the potential for developing reliable earthquake prediction tools. Full article

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19 pages, 1534 KiB

Open AccessReview

State of the Art of CFD-DEM Coupled Modeling and Its Application in Turbulent Flow-Induced Soil Erosion

by Jun Xu, Fei Wang and Ruth Abegaz

Geosciences 2025, 15(1), 21; https://doi.org/10.3390/geosciences15010021 - 10 Jan 2025

Viewed by 643

Abstract

Fluid–soil interaction plays a pivotal role in various geotechnical engineering applications, as it significantly influences processes such as erosion, sediment transport, and soil stability. Modeling fluid–soil particle interactions in these contexts presents substantial challenges due to the inherent complexity of the interactions occurring [...] Read more.

Fluid–soil interaction plays a pivotal role in various geotechnical engineering applications, as it significantly influences processes such as erosion, sediment transport, and soil stability. Modeling fluid–soil particle interactions in these contexts presents substantial challenges due to the inherent complexity of the interactions occurring across multiple characteristic scales. The primary challenge lies in the vast disparities in magnitude between these scales, which demand sophisticated modeling techniques to accurately capture the intricate dynamics involved. Coupled fluid–soil particle models have emerged as essential tools for understanding the mechanisms underlying fluid–soil interactions. Among these, the CFD-DEM (computational fluid dynamics–discrete element method) approach has gained significant attention. This method provides an effective compromise between high-resolution sub-particle fluid modeling and coarser mesh-based techniques for fluids and particles. By doing so, CFD-DEM facilitates large-scale simulations while maintaining computational efficiency, making it a promising solution for studying fluid–soil interactions in complex geotechnical scenarios. This review highlights the application of CFD-DEM models in geotechnical engineering, with a specific focus on soil erosion processes and the critical role of turbulent flow. It explores various fluid–soil particle interaction computational mechanisms and their implications for erosion dynamics, emphasizing several key aspects, including the following: laminar vs. turbulent flow models: understanding the distinctions between flow regimes is critical for accurately predicting fluid-induced soil particle movement. Shear stress effects: the influence of flow-induced shear stress on the detachment of soil particles is analyzed, particularly in erosion-prone environments. Sediment transport mechanisms: factors such as particle size, density, and water velocity are examined for their roles in governing sediment transport. Knowledge gaps and future directions: these involve identifying unresolved issues in current fluid–soil interaction models, with an emphasis on improving the accuracy and scalability of CFD-DEM simulations. By delving into these aspects, the review aims to advance the understanding of fluid–soil interactions and provide insights into optimizing modeling techniques for geotechnical engineering applications. It also outlines future research directions to bridge existing knowledge gaps, emphasizing the importance of integrating advanced turbulence modeling and computational strategies to enhance the predictive capabilities of fluid–soil interaction frameworks. Full article

(This article belongs to the Section Geomechanics)

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15 pages, 7788 KiB

Open AccessArticle

Accounting for the Compositional Nature of Geochemical Data to Improve the Interpretation of Their Univariate and Multivariate Spatial Patterns: A Case Study from the Campania Region (Italy)

by Lucia Rita Pacifico, Annalise Guarino, Antonio Iannone and Stefano Albanese

Geosciences 2025, 15(1), 20; https://doi.org/10.3390/geosciences15010020 - 9 Jan 2025

Viewed by 449

Abstract

This study investigates the application of Compositional Data Analysis (CoDA) and multivariate statistical techniques to geochemical data from the soils of the Campania region. The dataset examined includes 3571 soil samples analyzed for 37 chemical elements. Principal Component Analysis (PCA) was employed to [...] Read more.

This study investigates the application of Compositional Data Analysis (CoDA) and multivariate statistical techniques to geochemical data from the soils of the Campania region. The dataset examined includes 3571 soil samples analyzed for 37 chemical elements. Principal Component Analysis (PCA) was employed to reduce the dataset’s dimensionality and identify key relationships between elements. The first PCA identified groups of highly correlated variables, which were then reduced to 20 representative elements for a second PCA. The three most significant principal components (PC1, PC2, and PC3) explained approximately 65% of the total variability. PC1 (accounting for 29.97% of variability) revealed an anticorrelation between Ti, La, and Sc with Au, Hg, and Ag, with positive scores primarily located in the inland Apennine areas. PC2 (21.8%) was dominated by Na, K, and Cu, with positive scores corresponding to volcanic deposits, aligning with the dispersion patterns of historical Vesuvian eruption products. PC3 (11%) was associated with Ca and S, with higher scores found in the alluvial plains and inland areas. These results demonstrate the efficacy of CoDA in minimizing spurious correlations and uncovering latent relationships between elements, thereby enhancing the interpretation of natural and anthropogenic processes influencing soil variability in the region. Full article

(This article belongs to the Section Geochemistry)

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19 pages, 4126 KiB

Open AccessArticle

Relationship Between Thermal Conductivity, Mineral Composition and Major Element Composition in Rocks from Central and South Germany

by Oliver Suft, Hannes Hagenauer and David Bertermann

Geosciences 2025, 15(1), 19; https://doi.org/10.3390/geosciences15010019 - 9 Jan 2025

Viewed by 504

Abstract

Thermal conductivity is a decisive parameter in all geothermal applications. In addition to the influencing factors of density, saturation, porosity, temperature and pressure, it is, above all, the geochemical and mineralogical composition that determines the thermal conductivity in rocks and soils. This study [...] Read more.

Thermal conductivity is a decisive parameter in all geothermal applications. In addition to the influencing factors of density, saturation, porosity, temperature and pressure, it is, above all, the geochemical and mineralogical composition that determines the thermal conductivity in rocks and soils. This study focuses on selected rock samples from Southern and Central Germany regarding major element oxides and minerals as well as distributed thermal conductivity. We examined clastic and chemical sedimentary, as well as igneous and metamorphic rocks, ranging from the Paleozoic to Cenozoic age. Measurements were conducted by X-ray fluorescence analysis (XRF), X-ray diffraction (XRD) and optical scanning with a thermal conductivity scanner (TCS). The results show significant correlations between thermal and geochemical parameters. Chemical composition significantly impacts thermal conductivity. Higher quartz and SiO₂ contents generally lead to increased thermal conductivity, while aluminum silicates, common in clay minerals, correlate with lower conductivity. For carbonates, increased density or reduced porosity enhances conductivity. Structural differences and differing mineral concentrations influence the measurement variability along the sampling axis. This is especially visible in clastic sedimentary rock samples, where porosity decreases while cementation of the matrix increases thermal conductivity. Full article

(This article belongs to the Section Geochemistry)

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26 pages, 8054 KiB

Open AccessArticle

Integration and Application of a Fabric-Based Modified Cam-Clay Model in FLAC^3D

by Xiao-Wen Wang, Kai Cui, Yuan Ran, Yu Tian, Bo-Han Wu and Wen-Bin Xiao

Geosciences 2025, 15(1), 18; https://doi.org/10.3390/geosciences15010018 - 8 Jan 2025

Viewed by 381

Abstract

In order to consider the effect of fabric anisotropy in the analysis of geotechnical boundary value problems, this study proposes a modified model based on a fabric-based modified Cam-clay model, which can account for the anisotropic response of soil. The major modification of [...] Read more.

In order to consider the effect of fabric anisotropy in the analysis of geotechnical boundary value problems, this study proposes a modified model based on a fabric-based modified Cam-clay model, which can account for the anisotropic response of soil. The major modification of the original model aims to simplify the equations for numerical implementation by replacing the SMP strength criterion with the Lade’s strength criterion. This model comprehensively considers the inherent anisotropy, induced anisotropy, and three-dimensional strength characteristics of soil. The model is first numerically implemented using the elastic trial–plastic correction method, and then it is encapsulated into the FLAC^3D 6.0 software, and tested through conventional triaxial, embankment loading, and tunnel excavation experiments. Numerical simulation results indicate that considering anisotropy and three-dimensional strength in geotechnical engineering analysis is necessary. By accounting for the interaction between microstructure and macroscopic anisotropy, the model can more accurately represent soil behavior, providing significant advantages for geotechnical analysis. Full article

(This article belongs to the Section Geomechanics)

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26 pages, 4641 KiB

Open AccessArticle

Enhancing Safety in U.S. Coal Mines Through a Rib Support Recommendation Tool

by Alper Kirmaci, Dakshith Ruvin Wijesinghe, Dogukan Guner, Kutay E. Karadeniz, Cameron Mitchell and Taghi Sherizadeh

Geosciences 2025, 15(1), 17; https://doi.org/10.3390/geosciences15010017 - 8 Jan 2025

Viewed by 443

Abstract

Despite ongoing efforts to enhance coal rib stability, the underground coal mining sector continues to face incidents of rib failure, leading to injuries and fatalities. The development and validation of effective rib support systems are crucial for mitigating these risks. Unfortunately, a standardized [...] Read more.

Despite ongoing efforts to enhance coal rib stability, the underground coal mining sector continues to face incidents of rib failure, leading to injuries and fatalities. The development and validation of effective rib support systems are crucial for mitigating these risks. Unfortunately, a standardized design methodology that accommodates the diverse geological conditions of U.S. coal mines is missing. Current practices are often based on trial-and-error or outdated methods, yielding unreliable outcomes. This research aims to fill this gap by creating a comprehensive methodology for designing rib support systems suitable for U.S. underground mines. It encompasses in situ pull-out tests of coal rib bolts, numerical model validations, and parametric studies on variables affecting rib stability. A significant achievement of this study is the creation of the rib support recommendation tool (RSR), a user-friendly application that offers site-specific rib support advice. This tool leverages the results from parametric studies and improved Coal Pillar Rib Rating (CPRR) system values to recommend effective rib support. Validated by field data, the RSR tool promises to significantly improve mining safety and efficiency by providing a systematic and reliable method for rib support design, with ongoing efforts to further validate its effectiveness. Full article

(This article belongs to the Section Geomechanics)

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25 pages, 16213 KiB

Open AccessArticle

Imaging Shallow Velocity Structure of an Inactive Fault by Airgun Seismic Source: A Case Study of Xiliushui Fault in Qiliang Mountain

by Manzhong Qin, Baichen Wu, Yi Wang, Xueyi Shang, Yuansheng Zhang, Xuzhou Liu, Xiao Guo, Rui Zou, Yahong Wang and Dianfeng Sun

Geosciences 2025, 15(1), 16; https://doi.org/10.3390/geosciences15010016 - 7 Jan 2025

Viewed by 426

Abstract

We observed high-quality waves from a repeatable airgun seismic source recorded by a linear ultra-dense seismic array across the Xiliushui fault zone, one of the inactive faults in the Qilian Mountain, on the northeastern margin of the Tibetan Plateau, China. We used Snell’s [...] Read more.

We observed high-quality waves from a repeatable airgun seismic source recorded by a linear ultra-dense seismic array across the Xiliushui fault zone, one of the inactive faults in the Qilian Mountain, on the northeastern margin of the Tibetan Plateau, China. We used Snell’s law of seismic ray propagation to determine a simplified ambient velocity model. Based on the flexible and precise spectral element method, we computed broadband synthetic seismograms for a shallow low-velocity fault zone (FZ) to model the direct P-wave travel time delay and incident angle of the wavefield near the FZ. The FZ extent range and boundaries were inverted by apparent travel time delays and amplification patterns across the fault. According to prior information on the properties of the direct P-waves, we could constrain the inverse modeling and conduct a grid search for the fault parameters. The velocity reduction between the FZ and host rock, along with the dip angle of the FZ, were also constrained by the P-wave travel time delay systematic analysis and incoming angle of the P-waves. We found that the Xiliushui fault has a 70~80 m-wide low-velocity fault damage zone in which the P-wave velocity is reduced to ~40% with respect to the host rock. The fault damage zone dips ~35°southwest and extends to ~165 m in depth. The repeatability and environment protection characteristics of the airgun seismic survey and the economic benefits of a limited number of instruments setting are prominent. Full article

(This article belongs to the Special Issue Geophysical Inversion)

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30 pages, 9893 KiB

Open AccessArticle

Impacts of Land Use on Soil Erosion: RUSLE Analysis in a Sub-Basin of the Peruvian Amazon (2016–2022)

by Moises Ascencio-Sanchez, Cesar Padilla-Castro, Christian Riveros-Lizana, Rosa María Hermoza-Espezúa, Dayan Atalluz-Ganoza and Richard Solórzano-Acosta

Geosciences 2025, 15(1), 15; https://doi.org/10.3390/geosciences15010015 - 6 Jan 2025

Viewed by 738

Abstract

The Peruvian Amazon faces an increasing threat of soil erosion, driven by unsustainable agricultural practices and accelerated deforestation. In Neshuya (Ucayali region), agricultural activity has intensified since 2014, but the effect on soil erosion is unknown. The present study aimed to evaluate the [...] Read more.

The Peruvian Amazon faces an increasing threat of soil erosion, driven by unsustainable agricultural practices and accelerated deforestation. In Neshuya (Ucayali region), agricultural activity has intensified since 2014, but the effect on soil erosion is unknown. The present study aimed to evaluate the increase in erosion levels, at a sub-basin of the central–eastern Amazon of Peru, in a Geographic Information System (GIS) environment. The revised universal soil loss equation (RUSLE) model was used for assessing the effect of vegetation cover change from 2016 to 2022. In the Neshuya sub-basin (973.4 km²), the average erosion increased from 3.87 to 4.55 t ha⁻¹ year⁻¹, on average. In addition, there is great spatial variability in the values. In addition, 7.65% of the study area (74.52 km²) exceeds the soil loss tolerance limit (15 t ha⁻¹ year⁻¹). The deforestation rate was 17.99 km² year⁻¹ and by 2022 the forested area reached 237.65 km². In conclusion, the transition from forest to farmland was related to the most critical erosion values. Unsustainable soil management practices can be the underlying explanation of changes in soil chemical and physical properties. Also, social dynamic changes and differences in landscape patterns play a role. Full article

(This article belongs to the Topic Basin Analysis and Modelling)

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23 pages, 14180 KiB

Open AccessArticle

Preliminary Results of the Kuznetsk Coal Basin Cover Deposits Radon Hazard Assessment

by Timofey Leshukov, Konstantin Legoshchin, Elizaveta Baranova and Aleksey Larionov

Geosciences 2025, 15(1), 14; https://doi.org/10.3390/geosciences15010014 - 6 Jan 2025

Viewed by 470

Abstract

The study of the influence of geological structure (e.g., faults) on radon emanations is usually applicable provided that there are conditionally background (control) territories with which radon indicators will be compared. In the presented study, we selected an area where pre-Cenozoic faults that [...] Read more.

The study of the influence of geological structure (e.g., faults) on radon emanations is usually applicable provided that there are conditionally background (control) territories with which radon indicators will be compared. In the presented study, we selected an area where pre-Cenozoic faults that could potentially be associated with the radon hazard of the Kuznetsk coal basin were not identified. The cover deposits in the study area are represented by loamy and clayey strata overlying the Paleozoic sedimentary cycles. The radon field was estimated based on the radon flux density (RFD) and radon activity concentration (RAC) in the soil gas. The RAC was measured in two ways—by the sorption method on activated carbon and by the method of active sampling of soil gas from a borehole. At the same time, the role of meteorological conditions and the physical properties of the soil in the radon field was assessed. Our study shows that local variations in the physical properties of the soil are insignificant and do not have a significant effect on the RAC in the soil gas of the Kuznetsk coal basin, with the exception of soil moisture. High values of RAC in the territory considered as conditionally background, in the absence of pre-Cenozoic faults, suggest other causes (the presence of the latest Neogene–Quaternary faults, high concentrations of ²²⁶Ra, or other insufficiently studied causes). Due to the absence of faults, it is possible to assume a diffusion type of radon transfer in the geological environment, which indicates a shallow source of radon in such high concentrations. Our results indicate that studies of the ²²⁶Ra content and additional studies of the radon hazard of similar areas should also be carried out. Full article

(This article belongs to the Section Natural Hazards)

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24 pages, 35835 KiB

Open AccessArticle

Absent Voices and Unwarranted Presences: A Combined Multi-Approach to Mapping the Roman Hydraulic System Supplying Las Médulas Gold Mine (NW, Iberia)

by Javier Fernández-Lozano, Iván González-Pérez, Ángel González-Abajo, Enoc Sanz-Ablanedo and José Ramón Rodríguez-Pérez

Geosciences 2025, 15(1), 13; https://doi.org/10.3390/geosciences15010013 - 6 Jan 2025

Viewed by 2960

Abstract

This study analyses the Roman hydraulic system linked to Las Médulas gold mining complex in Northwest Iberia. The research includes a detailed mapping and assessment of the hydraulic network, which extends over 1110 km, using advanced geomatic techniques and an innovative script for [...] Read more.

This study analyses the Roman hydraulic system linked to Las Médulas gold mining complex in Northwest Iberia. The research includes a detailed mapping and assessment of the hydraulic network, which extends over 1110 km, using advanced geomatic techniques and an innovative script for tracing canals implemented in Matlab. The study reveals previously unidentified canals, improves existing cartographic representations, and addresses water sourcing and canal distribution uncertainties. It identifies 41 canals distributed between La Cabrera and El Bierzo regions, (33 and 8, respectively), with 14 canals supplying water to Las Médulas. Our study also provides evidence that this canal system had a wider purpose than simply supplying the mining works at Las Médulas. Furthermore, the findings presented here challenge established assumptions about the system’s water sources and offer new insights into how this outstanding canal system was built. Thus, this work not only provides a detailed map of the Las Médulas hydraulic system but also constitutes a model for an effective methodological approach for studying similar ancient hydraulic systems worldwide. Full article

(This article belongs to the Section Hydrogeology)

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16 pages, 5234 KiB

Open AccessArticle

Detection and Attribution of a Spatial Heterogeneity in the Temporal Evolution of Bulgarian River Discharge

by Natalya A. Kilifarska, Gergana I. Metodieva and Antonia Ch. Mokreva

Geosciences 2025, 15(1), 12; https://doi.org/10.3390/geosciences15010012 - 5 Jan 2025

Viewed by 525

Abstract

The hydrosphere is an element of the climate system and changes in the latter are reasonably projected over the river outflow. Climatic changes, however, are unevenly distributed over the Earth, and understanding their regional imprint on the hydrosphere is of great importance. In [...] Read more.

The hydrosphere is an element of the climate system and changes in the latter are reasonably projected over the river outflow. Climatic changes, however, are unevenly distributed over the Earth, and understanding their regional imprint on the hydrosphere is of great importance. In this study, we have conducted a statistical analysis of the monthly maximum and minimum river discharge recorded in 22 hydrological stations located on 19 of the Bulgarian rivers during the period 1993–2022. We have found that in half of the river basins, the trend of the spring maximum discharge is significantly positive (α = 0.05). In the other half of the stations, the trend is neutral. The stations with a positive trend are not randomly distributed but grouped, forming a pattern crossing the country from northwest to southeast. This pattern of trend distribution raises questions about the causes of the irregular hydrological response to the rising global near-surface temperatures. A comparison of hydrological data with some climatic variables (i.e., temperature, precipitation, and ozone at 70 hPa), combined with neural network analysis results, suggests ozone as a possible reason for the heterogeneous hydrological response. Its effect could be explained by an imposed episodic warming of the near-surface temperature due to fluctuations in the ozone density near the tropopause, which in turn favours the faster melting of ice and snow in the corresponding river basins. Full article

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20 pages, 3791 KiB

Open AccessArticle

Hydrometeorological Variability of Olive Ridley Sea Turtle (Lepidochelys olivacea) Nesting Beaches: Implications for Conservation Practices

by Anatoliy Filonov, Enrique Godínez-Domínguez, Iryna Tereshchenko, Cesar O. Monzon, David Avalos-Cueva and María del Refugio Barba-López

Geosciences 2025, 15(1), 11; https://doi.org/10.3390/geosciences15010011 - 5 Jan 2025

Viewed by 531

Abstract

The conservation of the olive ridley turtle (Lepidochelys olivacea) is increasingly critical due to declining global populations. This study investigates the influence of hydrometeorological conditions on the nesting season and annual hatchling sex ratios conducted at the Playón de Mismaloya Federal [...] Read more.

The conservation of the olive ridley turtle (Lepidochelys olivacea) is increasingly critical due to declining global populations. This study investigates the influence of hydrometeorological conditions on the nesting season and annual hatchling sex ratios conducted at the Playón de Mismaloya Federal Reserve in Tomatlán, Jalisco, Mexico. The research specifically examines variations in sand temperature at both the beach surface and nesting depths, with extended measurements taken at multiple depths (20, 40, 60, 80, and 100 cm) to analyze the vertical temperature gradient along the beach. Atmospheric parameters were modeled using Newton’s Cooling Law and solved with the finite difference method to estimate heat loss rates from beach sand to its surroundings, shedding light on microclimatic effects on incubation and embryonic development. Meteorological data were gathered from an automatic weather station, while sand temperatures were monitored with thermographs. During the warm period (approximately 32 °C), sand temperature showed a negative correlation with depth (20–100 cm), indicating cooler temperatures at greater depths. These conditions were associated with female-biased hatchling production. Conversely, the cold period (approximately 28 °C) led to male-biased hatchling production, with a positive correlation between sand and air temperatures. This study emphasizes the importance of monitoring in situ environmental conditions and extending the protection season until February to avoid the loss of male hatchlings. Full article

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44 pages, 7018 KiB

Open AccessReview

Rethinking the Lake History of Taylor Valley, Antarctica During the Ross Sea I Glaciation

by Michael S. Stone, Peter T. Doran and Krista F. Myers

Geosciences 2025, 15(1), 9; https://doi.org/10.3390/geosciences15010009 - 4 Jan 2025

Viewed by 596

Abstract

The Ross Sea I glaciation, marked by the northward advance of the Ross Ice Sheet (RIS) in the Ross Sea, east Antarctica, corresponds with the last major expansion of the West Antarctic Ice Sheet during the last glacial period. During its advance, the [...] Read more.

The Ross Sea I glaciation, marked by the northward advance of the Ross Ice Sheet (RIS) in the Ross Sea, east Antarctica, corresponds with the last major expansion of the West Antarctic Ice Sheet during the last glacial period. During its advance, the RIS was grounded along the southern Victoria Land coast, completely blocking the mouths of several of the McMurdo Dry Valleys (MDVs). Several authors have proposed that very large paleolakes, proglacial to the RIS, existed in many of the MDVs. Studies of these large paleolakes have been key in the interpretation of the regional landscape, climate, hydrology, and glacier and ice sheet movements. By far the most studied of these large paleolakes is Glacial Lake Washburn (GLW) in Taylor Valley. Here, we present a comprehensive review of literature related to GLW, focusing on the waters supplying the paleolake, signatures of the paleolake itself, and signatures of past glacial movements that controlled the spatial extent of GLW. We find that while a valley-wide proglacial lake likely did exist in Taylor Valley during the early stages of the Ross Sea I glaciation, during later stages two isolated lakes occupied the eastern and western sections of the valley, confined by an expansion of local alpine glaciers. Lake levels above ~140 m asl were confined to western Taylor Valley, and major lake level changes were likely driven by RIS movements, with climate variables playing a more minor role. These results may have major implications for our understanding of the MDVs and the RIS during the Ross Sea I glaciation. Full article

(This article belongs to the Section Cryosphere)

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32 pages, 10731 KiB

Open AccessArticle

Depositional Environments and Soft Sediment Deformation in the Early Jurassic Ammonitico Rosso Formation of Western Greece

by Vasilis Golfinopoulos, David J. W. Piper, Avraam Zelilidis, Georgia Pe-Piper, Penelope Papadopoulou, Nicolina Bourli and George Iliopoulos

Geosciences 2025, 15(1), 10; https://doi.org/10.3390/geosciences15010010 - 4 Jan 2025

Viewed by 722

Abstract

This study investigates the depositional environments and soft sediment deformation within the Early Jurassic Ammonitico Rosso Formation in the External Ionian Basin (Western Greece), focusing on its biostratigraphy, sedimentology, and tectonic activity. This research provides new insights into the depositional environment of the [...] Read more.

This study investigates the depositional environments and soft sediment deformation within the Early Jurassic Ammonitico Rosso Formation in the External Ionian Basin (Western Greece), focusing on its biostratigraphy, sedimentology, and tectonic activity. This research provides new insights into the depositional environment of the Ammonitico Rosso Formation and its transitions with the underlying and overlying formations. Syn-rift tectonics at the time of deposition formed half-grabens, which influenced sedimentary processes and created conditions for seabed slumping. Detailed field mapping and microfacies analysis revealed two distinct depositional environments: deep-water to open-shelf settings and platform-margin reefs. The entire Ammonitico Rosso Formation is allochthonous, deposited as repetitive slices of little-disturbed stratified sediments capped by debrites near the toe of a complex submarine landslide. The presence of well-preserved fossils, such as planktonic and benthic foraminifera, Radiolaria (both Spumellaria and Nassellaria), and ammonites, allowed precise age determinations, suggesting that the first appearance of Globuligerina might predate previous records, occurring first in the Pliensbachian rather than the Toarcian. These findings contribute to the ongoing debate on the depth and conditions of Ammonitico Rosso deposition, supporting the hypothesis of a relatively deep, open-shelf environment influenced by slope instability. Full article

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

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20 pages, 7793 KiB

Open AccessArticle

Noise Elimination for Wide Field Electromagnetic Data via Improved Dung Beetle Optimized Gated Recurrent Unit

by Zhongyuan Liu, Xian Zhang, Diquan Li, Shupeng Liu and Ke Cao

Geosciences 2025, 15(1), 8; https://doi.org/10.3390/geosciences15010008 - 3 Jan 2025

Viewed by 400

Abstract

Noise profoundly affects the quality of electromagnetic data, and selecting the appropriate hyperparameters for machine learning models poses a significant challenge. Consequently, the current machine learning denoising techniques fall short in delivering precise processing of Wide Field Electromagnetic Method (WFEM) data. To eliminate [...] Read more.

Noise profoundly affects the quality of electromagnetic data, and selecting the appropriate hyperparameters for machine learning models poses a significant challenge. Consequently, the current machine learning denoising techniques fall short in delivering precise processing of Wide Field Electromagnetic Method (WFEM) data. To eliminate the noise, this paper presents an electromagnetic data denoising approach based on the improved dung beetle optimized (IDBO) gated recurrent unit (GRU) and its application. Firstly, Spatial Pyramid Matching (SPM) chaotic mapping, variable spiral strategy, Levy flight mechanism, and adaptive T-distribution variation perturbation strategy were utilized to enhance the DBO algorithm. Subsequently, the mean square error is employed as the fitness of the IDBO algorithm to achieve the hyperparameter optimization of the GRU algorithm. Finally, the IDBO-GRU method is applied to the denoising processing of WFEM data. Experiments demonstrate that the optimization capacity of the IDBO algorithm is conspicuously superior to other intelligent optimization algorithms, and the IDBO-GRU algorithm surpasses the probabilistic neural network (PNN) and the GRU algorithm in the denoising accuracy of WFEM data. Moreover, the time domain of the processed WFEM data is more in line with periodic signal characteristics, its overall data quality is significantly enhanced, and the electric field curve is more stable. Therefore, the IDBO-GRU is more adept at processing the time domain sequence, and the application results also validate that the proposed method can offer technical support for electromagnetic inversion interpretation. Full article

(This article belongs to the Section Geophysics)

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19 pages, 19539 KiB

Open AccessArticle

Seabed Acoustic Mapping Revealing an Uncharted Habitat of Circular Depressions Along the Southeast Brazilian Outer Shelf

by Ana Carolina Lavagnino, Marcos Daniel Leite, Tarcila Franco, Pedro Smith Menandro, Fernanda Vedoato Vieira, Geandré Carlos Boni and Alex Cardoso Bastos

Geosciences 2025, 15(1), 7; https://doi.org/10.3390/geosciences15010007 - 1 Jan 2025

Viewed by 728

Abstract

Initiatives such as the United Nations Decade of Ocean Science for Sustainable Development and Seabed 2030 promote seabed mapping worldwide. In Brazil, especially on the Espírito Santo Continental Shelf, high-resolution seabed mapping has revealed an unknown complex seascape. Circular depressions (CDs) were mapped [...] Read more.

Initiatives such as the United Nations Decade of Ocean Science for Sustainable Development and Seabed 2030 promote seabed mapping worldwide. In Brazil, especially on the Espírito Santo Continental Shelf, high-resolution seabed mapping has revealed an unknown complex seascape. Circular depressions (CDs) were mapped for the first time in the Costa das Algas Marine Protection Area. Herein, we aim to present the CD metrics characteristics and discuss their relationship with morphology and relevance as a habitat based on multibeam bathymetry and ground truthing. A total of 3660 depressions were mapped between 46 and 85 m in depth, reaching an area of 460 m² and 5 m relief. The continental shelf morphology was subdivided into three sectors based on morphology: inter-valleys, valley edges, and valley flanks, and eleven sites were selected for direct sampling/imaging at the CDs along the sectors. The direct sampling was carried out by scuba-diving with video images and sediment samples collected inside and outside the depressions. The deeper central parts of the circular depressions appear to function as a sink, presenting aggregations of rhodoliths or other carbonate fragments. In most inter-valley depressions, mounds were observed along the edges of the depression. We did not have any indication of gas seeps and no clear sedimentological or morphological control on their occurrence. We first hypothesize that their origin results from combined diachronous processes. The circular depressions mapped at high resolution could be related to sea level processes acting during the last glacial period and shelf exposure, i.e., relict features. The CDs are responsible for biomass aggregation and fish bioturbation, forming holes and rubble mounds, representing a modern process occurring on a centimetric scale. The data collected so far indicate that this fine-scale feature is an important habitat for different fish species. The modern maintenance of these structures could be due to low sedimentation regime areas shaped by biotic excavation. Full article

(This article belongs to the Special Issue Progress in Seafloor Mapping)

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21 pages, 7673 KiB

Open AccessArticle

A Developed Computational Code to Build a 3D Fracture Network to Reduce the Uncertainty of Fracture Parameter Generation (A Case Study of the Emamzadeh Hashem Tunnel)

by Mahin Etemadifar, Gholamreza Shoaei, Morteza Javadi and Arash Hashemnejad

Geosciences 2025, 15(1), 6; https://doi.org/10.3390/geosciences15010006 - 1 Jan 2025

Viewed by 562

Abstract

Rock masses comprise intact rock and discontinuities, such as fractures, which significantly influence their mechanical and hydraulic properties. Uncertainty in constructing the fracture network can notably affect the outcomes of sensitive analyses, including tunnel stability simulations. Thus, accurately determining specific parameters of rock [...] Read more.

Rock masses comprise intact rock and discontinuities, such as fractures, which significantly influence their mechanical and hydraulic properties. Uncertainty in constructing the fracture network can notably affect the outcomes of sensitive analyses, including tunnel stability simulations. Thus, accurately determining specific parameters of rock joints, including orientation and trace length, is essential. A discrete fracture network (DFN) is one technique used to simulate jointed rock. However, engineers often face challenges due to the inherent uncertainty in building a fracture network using statistical distribution functions. This study analyzed the fracture network of the Emamzadeh Hashem tunnel using MATLAB-developed code and 3DEC software. It focused on the impact of statistical distribution functions on the uncertainty of fracture network construction. The results reveal that using a negative exponential distribution can introduce significant errors in constructing the fracture network, especially when generating the dip direction. The parametric study shows that employing statistical distribution functions that account for data variance in the Probability Distribution Function (PDF) can enhance the accuracy of generating fracture parameters, such as dip, dip direction, and trace length, thereby reducing uncertainty in fracture network construction. Full article

(This article belongs to the Section Geomechanics)

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4 pages, 162 KiB

Open AccessEditorial

Evolution of Modern and Ancient Orogenic Belts

by Rodolfo Carosi, Mario Da Costa Campos Neto, Haakon Fossen, Chiara Montomoli and Matteo Simonetti

Geosciences 2025, 15(1), 5; https://doi.org/10.3390/geosciences15010005 - 30 Dec 2024

Viewed by 513

Abstract

Orogens are broadly grouped into accretionary and collisional types [...] Full article

(This article belongs to the Special Issue Evolution of Modern and Ancient Orogenic Belts)

22 pages, 15137 KiB

Open AccessArticle

Sensitivity Analysis on the Impact of Input Parameters on Seismic Hazard Results: A Case Study of Central America

by Carlos Gamboa-Canté, Mario Arroyo-Solórzano, Alicia Rivas-Medina and Belén Benito

Geosciences 2025, 15(1), 4; https://doi.org/10.3390/geosciences15010004 - 29 Dec 2024

Viewed by 1110

Abstract

We present a sensitivity analysis on the impact of input parameters and methods used on the results of a probabilistic seismic hazard assessment (PSHA). The accurate estimation of the parameters in recurrence models (declustering and fitting methods), along with the selection of scaling [...] Read more.

We present a sensitivity analysis on the impact of input parameters and methods used on the results of a probabilistic seismic hazard assessment (PSHA). The accurate estimation of the parameters in recurrence models (declustering and fitting methods), along with the selection of scaling relationships for determining maximum magnitude and the selection of ground motion models (GMMs), enhance control over epistemic uncertainties when constructing the logic tree, minimizing final calculation errors and producing credible results for the study region. This study focuses on Central America, utilizing recent data from seismic, geological, and geophysical studies to improve uncertainty analyses through classic statistical methods. The results demonstrate that proper fitting of the recurrence model can stabilize acceleration variations regardless of the declustering method or b-value fitting method used. Regarding scaling relationships, their low impact on the final results is noted, provided the models are tailored to the tectonic regime under study. Finally, it is shown that the GMM contributes the most variability to seismic hazard results; therefore, their selection should be conditioned on calibration with observed data through residual analysis where region-specific models are not available. Full article

(This article belongs to the Section Geophysics)

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