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Geosciences, Volume 10, Issue 2 (February 2020) – 47 articles

Cover Story (view full-size image): Hydrovolcanism is a type of volcanism where magma and water interact either explosively or non-explosively. Hydrovolcanism is commonly used as a synonym for phreatomagmatism. However, recently, phreatomagmatism has appeared more in association with volcanism that occurs in shallow subaqueous or terrestrial settings. Here, a revised and reviewed classification scheme is suggested for hydrovolcanism with special reference to its explosive varieties, based on their geo-environment in which magma–water interaction takes place and explosivity plus mode of energy transfer are required to generate kinetic energy to produce pyroclasts. Explosive hydrovolcanism is discussed here from a field context, from the perspective of monogenetic volcanism. View this paper
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Article
The Effects of Slope Initialization on the Numerical Model Predictions of the Slope-Vegetation-Atmosphere Interaction
Geosciences 2020, 10(2), 85; https://doi.org/10.3390/geosciences10020085 - 24 Feb 2020
Cited by 5 | Viewed by 948
Abstract
Deep slope movements and, eventually, slope failure, have been often interpreted to be due to slope-vegetation-atmosphere interaction on slopes formed of clayey materials in the Italian Southern-Eastern Apennines, as reported in the literature. Such slopes are generally formed of flysch, within which clay [...] Read more.
Deep slope movements and, eventually, slope failure, have been often interpreted to be due to slope-vegetation-atmosphere interaction on slopes formed of clayey materials in the Italian Southern-Eastern Apennines, as reported in the literature. Such slopes are generally formed of flysch, within which clay is the main lithotype. Such clays are characterized by a disturbed meso-fabric, as an effect of the intense tectonics. The paper presents the results of coupled hydromechanical numerical analyses of the slope-vegetation-atmosphere interaction for a clay slope representative for the geomechanical scenario where such climate-induced deep slope movements have been repeatedly recorded. In the analyses, different model initialization procedures and parameter values were adopted. The comparison of the numerical results with the site data is aimed at assessing the effects of the soil-vegetation-atmosphere interaction taking place in the top strata of the slope, on the stress-strain conditions across the whole slope, and on the slope stability. The comparison between the numerical results of the analyses carried out entailing different initialization stages are intended to evaluate the influence of such a stage on the model predictions. It is found that only when the slope model initialization accounts for the slope loading history, developed over geological time, the numerical predictions get close to the site observations. In such case, the numerical results confirm that deep movements consequent to progressive failure may take place in clay slopes due to the slope-vegetation-atmosphere interaction. Full article
(This article belongs to the Special Issue Innovative Strategies for Sustainable Mitigation of Landslide Risk)
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Article
Late Quaternary Tectonic Activity of the Udine-Buttrio Thrust, Friulian Plain, NE Italy
Geosciences 2020, 10(2), 84; https://doi.org/10.3390/geosciences10020084 - 23 Feb 2020
Cited by 1 | Viewed by 1414
Abstract
The NW-SE trending Udine-Buttrio Thrust is a partly blind fault that affects the Friulian plain southeast of Udine in NE Italy. It is part of a wider fault system that accommodates the northward motion of the Adriatic plate. Although seismic reflection data and [...] Read more.
The NW-SE trending Udine-Buttrio Thrust is a partly blind fault that affects the Friulian plain southeast of Udine in NE Italy. It is part of a wider fault system that accommodates the northward motion of the Adriatic plate. Although seismic reflection data and morphological evidence show that the fault was active during the Quaternary, comparably little is known about its tectonic activity. We used high-resolution digital elevation models to investigate the surface expression of the fault. Measured vertical surface offsets show significant changes along strike with uplift rates varying between 0 and 0.5 mm/yr. We then analyze a topographic scarp near the village of Manzano in more detail. Field mapping and geophysical prospections (Georadar and Electrical Resistivity Tomography) were used to image the subsurface geometry of the fault. We found vertical offsets of 1–3 m in Natisone River terraces younger than 20 ka. The geophysical data allowed the identification of deformation of the fluvial sediments, supporting the idea that the topographic scarp is a tectonic feature and that the terraces have been uplifted systematically over time. Our findings fit the long-term behaviour of the Udine-Buttrio Thrust. We estimate a post-glacial vertical uplift rate of 0.08–0.17 mm/yr recorded by the offset terraces. Our results shed light on the Late Quaternary behaviour of this thrust fault in the complicated regional tectonic setting and inform about its hitherto overlooked possible seismic hazard. Full article
(This article belongs to the Special Issue Seismic Sequence in Mediterranean Region)
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Article
Morphotectonic Kinematic Indicators along the Vigan-Aggao Fault: The Western Deformation Front of the Philippine Fault Zone in Northern Luzon, the Philippines
Geosciences 2020, 10(2), 83; https://doi.org/10.3390/geosciences10020083 - 22 Feb 2020
Cited by 1 | Viewed by 6850
Abstract
The Vigan-Aggao Fault is a 140-km-long complex active fault system consisting of multiple traces in the westernmost part of the Philippine Fault Zone (PFZ) in northern Luzon, the Philippines. In this paper, its traces, segmentation, and oblique left-lateral strike-slip motion are determined from [...] Read more.
The Vigan-Aggao Fault is a 140-km-long complex active fault system consisting of multiple traces in the westernmost part of the Philippine Fault Zone (PFZ) in northern Luzon, the Philippines. In this paper, its traces, segmentation, and oblique left-lateral strike-slip motion are determined from horizontal and vertical displacements measured from over a thousand piercing points pricked from displaced spurs and streams observed from Google Earth Pro satellite images. This work marks the first instance of the extensive use of Google Earth as a tool in mapping and determining the kinematics of active faults. Complete 3D image coverage of a major thoroughgoing active fault system is freely and easily accessible on the Google Earth Pro platform. It provides a great advantage to researchers collecting morphotectonic displacement data, especially where access to aerial photos covering the entire fault system is next to impossible. This tool has not been applied in the past due to apprehensions on the positional measurement accuracy (mainly of the vertical component). The new method outlined in this paper demonstrates the applicability of this tool in the detailed mapping of active fault traces through a neotectonic analysis of fault-zone features. From the sense of motion of the active faults in northern Luzon and of the major bounding faults in central Luzon, the nature of deformation in these regions can be inferred. An understanding of the kinematics is critical in appreciating the distribution and the preferred mode of accommodation of deformation by faulting in central and northern Luzon resulting from oblique convergence of the Sunda Plate and the Philippine Sea Plate. The location, extent, segmentation patterns, and sense of motion of active faults are critical in coming up with reasonable estimates of the hazards involved and identifying areas prone to these hazards. The magnitude of earthquakes is also partly dependent on the type and nature of fault movement. With a proper evaluation of these parameters, earthquake hazards and their effects in different tectonic settings worldwide can be estimated more accurately. Full article
(This article belongs to the Section Natural Hazards)
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Article
Design Strategies to Mitigate Slope Instabilities in Structurally Complex Formations
Geosciences 2020, 10(2), 82; https://doi.org/10.3390/geosciences10020082 - 22 Feb 2020
Cited by 2 | Viewed by 777
Abstract
Stiff jointed clays (SJC) belong to so-called structurally complex formations in which the macroscale features of the deposit, that is the pattern of discontinuities affecting the soil mass, influence its response at the scale of engineering works. Such peculiar response was largely recognized [...] Read more.
Stiff jointed clays (SJC) belong to so-called structurally complex formations in which the macroscale features of the deposit, that is the pattern of discontinuities affecting the soil mass, influence its response at the scale of engineering works. Such peculiar response was largely recognized during the excavation works carried out for the construction of two new road segments in southern Italy, where several structurally conditioned instability processes were triggered during excavation works. These phenomena mainly involved the Plio-Pleistocene marine clayey formation outcropping along the East coast of the Calabria region, where it constitutes most of the hills interested by construction works. Under a geotechnical perspective, the SJC-formation exhibits good mechanical characteristics at the scale of samples but, if considered as a whole, its behaviour is governed by the presence of discontinuities along which strength is typically at residual. Building on the author’s experience of some exemplary failure events, this paper aims at defining possible design strategies to minimize the risk of adverse and unexpected instability phenomena during construction in structurally complex formations. Design strategies oriented at reducing and possibly avoiding stress releases in the zone of influence were found to be most effective at preventing failures or restoring safety after the occurrence of a failure event. Full article
(This article belongs to the Special Issue Innovative Strategies for Sustainable Mitigation of Landslide Risk)
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Article
Moroccan Groundwater Resources and Evolution with Global Climate Changes
Geosciences 2020, 10(2), 81; https://doi.org/10.3390/geosciences10020081 - 22 Feb 2020
Cited by 11 | Viewed by 1589
Abstract
In semi-arid areas, many ecosystems and activities depend essentially on water availability. In Morocco, the increase of water demands combined to climate change induced decrease of precipitation put a lot of pressure on groundwater. This paper reports the results of updating and evaluation [...] Read more.
In semi-arid areas, many ecosystems and activities depend essentially on water availability. In Morocco, the increase of water demands combined to climate change induced decrease of precipitation put a lot of pressure on groundwater. This paper reports the results of updating and evaluation of groundwater datasets with regards to climate scenarios and institutional choices. The continuous imbalance between groundwater extraction and recharge caused a dramatic decline in groundwater levels (20 to 65 m in the past 30 years). Additionally, Morocco suffers from the degradation in groundwater quality due to seawater intrusion, nitrate pollution and natural salinity changes. Climate data analysis and scenarios predict that temperatures will increase by 2 to 4 °C and precipitation will decrease by 53% in all catchments over this century. Consequently, surface water availability will drastically decrease, which will lead to more extensive use of groundwater. Without appropriate measures, this situation will jeopardize water security in Morocco. In this paper, we zoom on the case the Souss-Massa basin, where management plans (artificial recharge, seawater desalination, and wastewater reuse) have been adopted to restore groundwater imbalance or, at least, mitigate the recorded deficits. These plans may save water for future generations and sustain crop production. Full article
(This article belongs to the Special Issue Groundwater in arid and semiarid areas)
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Article
Detrital Zircon Provenance and Lithofacies Associations of Montmorillonitic Sands in the Maastrichtian Ripley Formation: Implications for Mississippi Embayment Paleodrainage Patterns and Paleogeography
Geosciences 2020, 10(2), 80; https://doi.org/10.3390/geosciences10020080 - 22 Feb 2020
Viewed by 971
Abstract
We provide new detrital zircon evidence to support a Maastrichtian age for the establishment of the present-day Mississippi River drainage system. Fieldwork conducted in Pontotoc County, Mississippi, targeted two sites containing montmorillonitic sand in the Maastrichtian Ripley Formation. U-Pb detrital zircon (DZ) ages [...] Read more.
We provide new detrital zircon evidence to support a Maastrichtian age for the establishment of the present-day Mississippi River drainage system. Fieldwork conducted in Pontotoc County, Mississippi, targeted two sites containing montmorillonitic sand in the Maastrichtian Ripley Formation. U-Pb detrital zircon (DZ) ages from these sands (n = 649) ranged from Mesoarchean (~2870 Ma) to Pennsylvanian (~305 Ma) and contained ~91% Appalachian-derived grains, including Appalachian–Ouachita, Gondwanan Terranes, and Grenville source terranes. Other minor source regions include the Mid-Continent Granite–Rhyolite Province, Yavapai–Mazatzal, Trans-Hudson/Penokean, and Superior. This indicates that sediment sourced from the Appalachian Foreland Basin (with very minor input from a northern or northwestern source) was being routed through the Mississippi Embayment (MSE) in the Maastrichtian. We recognize six lithofacies in the field areas interpreted as barrier island to shelf environments. Statistically significant differences between DZ populations and clay mineralogy from both sites indicate that two distinct fluvial systems emptied into a shared back-barrier setting, which experienced volcanic ash input. The stratigraphic positions of the montmorillonitic sands suggest that these deposits represent some of the youngest Late Cretaceous volcanism in the MSE. Full article
(This article belongs to the Section Geochemistry)
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Article
Low-Cost GNSS Software Receiver Performance Assessment
Geosciences 2020, 10(2), 79; https://doi.org/10.3390/geosciences10020079 - 21 Feb 2020
Cited by 3 | Viewed by 1310
Abstract
The Software-Defined Receiver (SDR) is a rapidly evolving technology which is a useful tool for researchers and allows users an extreme level customization. The main aim of this work is the assessment of the performance of the combination consisting of the Global Navigation [...] Read more.
The Software-Defined Receiver (SDR) is a rapidly evolving technology which is a useful tool for researchers and allows users an extreme level customization. The main aim of this work is the assessment of the performance of the combination consisting of the Global Navigation Satellite Systems Software-Defined Receiver (GNSS-SDR), developed by CTTC (Centre Tecnològic de Telecomunicacions de la Catalunya), and a low-cost front-end. GNSS signals were acquired by a Nuand bladeRF x-40 front-end fed by the TOPCON PG-A1 antenna. Particular attention was paid to the study of the clock-steering mechanism due to the low-cost characteristics of the bladeRF x-40 clock. Two different tests were carried out: In the first test, the clock-steering algorithm was activated, while in the second, it was deactivated. The tests were conducted in a highly degraded scenario where the receiver was surrounded by tall buildings. Single-Point and Code Differential positioning were computed. The achieved results show that the steering function guarantees the availability of more solutions, but the DRMS is quite the same in the two tests. Full article
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Article
Bat Algorithm Based Non-linear Contrast Stretching for Satellite Image Enhancement
Geosciences 2020, 10(2), 78; https://doi.org/10.3390/geosciences10020078 - 21 Feb 2020
Cited by 4 | Viewed by 836
Abstract
The remote sensing images acquired from the satellites are low contrast images. The availability of low contrast images and failure of the traditional methods such as Histogram Equalization and Gamma correction in preserving the brightness levels in the image are the main issues [...] Read more.
The remote sensing images acquired from the satellites are low contrast images. The availability of low contrast images and failure of the traditional methods such as Histogram Equalization and Gamma correction in preserving the brightness levels in the image are the main issues in satellite image processing. This paper proposes an optimized contrast stretching using non-linear transformation for image enhancement. The non-linear transformation is influenced by the appropriate choice of control parameters for the sample images since manual tuning for individual images is tedious. A Bat algorithm based tuning is employed for the automated selection of control parameters in the transformation. The performance of the optimization algorithm is compared against other metaheuristic algorithms such as Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO). It is noted that the bat algorithm based contrast enhancement outperforms the other optimization techniques in terms of metrics such as Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE), Absolute Mean Brightness Error (AMBE), Entropy and CPU time (Central Processing Unit). Full article
(This article belongs to the Special Issue Image processing and satellite imagery analysis in environments)
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Review
A Review of Russian Snow Avalanche Models—From Analytical Solutions to Novel 3D Models
Geosciences 2020, 10(2), 77; https://doi.org/10.3390/geosciences10020077 - 20 Feb 2020
Cited by 4 | Viewed by 887
Abstract
The article is a review of mathematical models of snow avalanches that have been proposed since the middle of the 20th century and are still in use. The main attention is paid to the work of researchers from the Soviet Union and Russia, [...] Read more.
The article is a review of mathematical models of snow avalanches that have been proposed since the middle of the 20th century and are still in use. The main attention is paid to the work of researchers from the Soviet Union and Russia, since many of their works were published only in Russian and are not widely available. Mathematical models of various levels of complexity for avalanches of various types—from dense to powder-snow avalanches—are discussed. Analytical solutions including formulas for the avalanche front speed are described. The results of simulations of the movement of avalanches are given that were used to create avalanche hazard maps. The last part of the article is devoted to constructing models of a new type, in which avalanches are considered as laminar or turbulent flows of non-Newtonian fluids, using the full (not depth-averaged) equations of continuum mechanics. The results of a numerical study of the effect of non-Newtonian rheology and mass entrainment on the avalanche dynamics are presented. Full article
(This article belongs to the Special Issue Snow Avalanche Dynamics)
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Article
Three-Dimensional Response of the Supported-Deep Excavation System: Case Study of a Large Scale Underground Metro Station
Geosciences 2020, 10(2), 76; https://doi.org/10.3390/geosciences10020076 - 19 Feb 2020
Cited by 2 | Viewed by 912
Abstract
The complexities and the economic computational infeasibility associated in some cases, with three-dimensional finite element models, has imposed a motive for many investigators to accept numerical modeling simplification solutions such as assuming two-dimensional (2D) plane strain conditions in simulation of several supported-deep excavation [...] Read more.
The complexities and the economic computational infeasibility associated in some cases, with three-dimensional finite element models, has imposed a motive for many investigators to accept numerical modeling simplification solutions such as assuming two-dimensional (2D) plane strain conditions in simulation of several supported-deep excavation problems, especially for cases with a relatively high aspect ratio in plan dimensions. In this research, a two-dimensional finite element model was established to simulate the behavior of the supporting system of a large-scale deep excavation utilized in the construction of an underground metro station Rod El Farrag project (Egypt). The essential geotechnical engineering properties of soil layers were calculated using results of in-situ and laboratory tests and empirical correlations with SPT-N values. On the other hand, a three-dimensional finite element model was established with the same parameters adopted in the two-dimensional model. Sufficient sensitivity numerical analyses were performed to make the three-dimensional finite element model economically feasible. Results of the two-dimensional model were compared with those obtained from the field measurements and the three-dimensional numerical model. The comparison results showed that 3D high stiffening at the primary walls’ corners and also at the locations of cross walls has a significant effect on both the lateral wall deformations and the neighboring soil vertical settlement. Full article
(This article belongs to the Special Issue Urban Geophysics)
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Article
Study on Methods to Control Interstory Deflections
Geosciences 2020, 10(2), 75; https://doi.org/10.3390/geosciences10020075 - 18 Feb 2020
Cited by 4 | Viewed by 687
Abstract
One of the possibilities to prevent building pounding between two adjacent structures is to consider appropriate in-between separation distance. Another approach might be focused on controlling the relative displacements during seismic excitations. Although the majority of building codes around the world recommend the [...] Read more.
One of the possibilities to prevent building pounding between two adjacent structures is to consider appropriate in-between separation distance. Another approach might be focused on controlling the relative displacements during seismic excitations. Although the majority of building codes around the world recommend the use of some equations of various distances between structures to avoid pounding; a lot of reports after earthquakes have obviously shown that safety situation or economic consideration is not always provided due to the collisions between buildings and high cost of land; respectively. The aim of the present paper is to focus the analysis on the properties of structures and conduct an in-depth analysis of available methods to control interstory deflections so as to prevent pounding. For this purpose, a numerical lumped mass model of the five-story building has been considered and its response under different earthquake records has been investigated. Firstly, the influence of the change in structural properties (story stiffness; mass and damping) has been examined. Then the application of tuned mass damper, base isolation and base isolation with rubber bumpers has been considered. The results of comparative analyses clearly indicate that using base isolation, with the addition of bumpers, can be selected as the best method to control building deflections and decrease absolute lateral displacement between two buildings so as to prevent their pounding during earthquakes Full article
(This article belongs to the Section Natural Hazards)
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Article
Controls on Gas Domains and Production Behaviour in A High-Rank CSG Reservoir: Insights from Molecular and Isotopic Chemistry of Co-Produced Waters and Gases from the Bowen Basin, Australia
Geosciences 2020, 10(2), 74; https://doi.org/10.3390/geosciences10020074 - 18 Feb 2020
Cited by 2 | Viewed by 731
Abstract
This paper uses hydrochemical and multi-isotope analysis to investigate geological controls on coal seam gas (CSG) saturation domains and gas well production performance in a high-rank (vitrinite reflectance (Rv) > 1.1) CSG field in the north-western Bowen Basin, Australia. New hydrochemical and stable [...] Read more.
This paper uses hydrochemical and multi-isotope analysis to investigate geological controls on coal seam gas (CSG) saturation domains and gas well production performance in a high-rank (vitrinite reflectance (Rv) > 1.1) CSG field in the north-western Bowen Basin, Australia. New hydrochemical and stable isotope data were combined with existing geochemical datasets to refine hypotheses on the distribution and origins of CSG in two highly compartmentalized Permian coal seams. Stable isotopic results suggest that geographic variations in gas content, saturation and production reflect the extent of secondary microbial gas generation and retention as a function of hydrodynamics. δ13C and δ2H data support a gas mixing hypothesis with δ13C-CH4 increasing from secondary biogenic values to thermogenic values at depth (δ13C −62.2‰ to −46.3‰), whereas correlated methane and carbon dioxide carbon isotope compositions, Δ13C(CO2–CH4) values and δ13CDIC/alkalinity trends are largely consistent with microbial CO2 reduction. In addition, below 200 m, the majority of δ13C-CO2 values are positive (δ13C: −1.2‰ to 7.1‰) and δ13CDIC shows an erratic increase with depth for both seams that is characteristic of evolution via microbial activity. The progression of carbon isotope values along the CO2 reduction fractionation line suggests progressive depletion of the CO2 reservoir with increasing depth. Faults clearly segment coal seams into areas having significantly different production, with results of geochemical analysis suggesting that pooling of biogenic gas and waters and enhanced methanogenesis occur north of a faulted hinge zone. Full article
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Review
Taxonomic Review of Fossil Coleopterous Families (Insecta, Coleoptera). Suborder Archostemata: Superfamilies Coleopseoidea and Cupedoidea
Geosciences 2020, 10(2), 73; https://doi.org/10.3390/geosciences10020073 - 17 Feb 2020
Cited by 7 | Viewed by 1367
Abstract
The paper is the first of a series, which aims to present a consistent interpretation of the suprageneric taxa of fossil beetles in the current century and their generic and species composition. Order Coleoptera is considered in composition of the superorder Coleopteroidea Handlirsch, [...] Read more.
The paper is the first of a series, which aims to present a consistent interpretation of the suprageneric taxa of fossil beetles in the current century and their generic and species composition. Order Coleoptera is considered in composition of the superorder Coleopteroidea Handlirsch, 1903 (= Coleopterida sensu Boudreaux, 1979, nec Pearse, 1936) together with orders Skleroptera and Strepsiptera, and also with the family Umenocoleidae of unclear position. This paper includes the archostematan superfamilies Coleopseoidea and Cupedoidea of the infraorder Cupediformia, i.e., Coleopseidae (one genus and one species), Tshekardocoleidae (12 genera, 15 species), Labradorocoleidae (one genus, one species), Permocupedidae (together with Taldycupedinae, stat. nov., 24 genera and 54 species) and Cupedidae (three subfamilies, 49 genera, 253 species). The preliminary information on structure of the larva of Tshekardocoleidae from Tshekarda is done. There are also described the new taxa: genus Afrotaldycupes Kirejtshuk, gen. nov. with the type species: genus Taldycupes africanus Ponomarenko in Ponomarenko & Mostovski, 2005 [Afrotaldycupes africanus comb. nov.] and Afrotaldycupes lidgettoniensis (Ponomarenko in Ponomarenko & Mostovski, 2005), comb. nov. [Taldycupes]; genus Allophalerus Kirejtshuk, gen. nov. with the type species: Tetraphalerus aphaleratus Ponomarenko, 1969 [Allophalerus aphaleratus comb. nov.], and also with Allophalerus antiquus (Ponomarenko, 1964), comb. nov. [Tetraphalerus], Allophalerus bontsaganensis (Ponomarenko, 1997), comb. nov. [Tetraphalerus], Allophalerus incertus (Ponomarenko, 1969), comb. nov. [Tetraphalerus], Allophalerus latus (Tan, Ren et Shih, 2007), comb. nov. [Tetraphalerus], Allophalerus maximus (Ponomarenko, 1968), comb. nov. [Tetraphalerus], Allophalerus okhotensis (Ponomarenko, 1993), comb. nov. [Tetraphalerus], Allophalerus tenuipes (Ponomarenko, 1964), comb. nov. [Tetraphalerus], Allophalerus verrucosus (Ponomarenko, 1966), comb. nov. [Tetraphalerus]; genus Bukhkalius Kirejtshuk et Jarzembowski, gen. nov. with the type species: Tetraphalerus lindae Jarzembowski, Wang et Zheng, 2017 [Bukhkalius lindae comb. nov.]; genus Burmocoleus Kirejtshuk, gen. nov. with the type species: Burmocoleus prisnyi sp. nov. and Burmocoleus zhiyuani (Liu, Tan, Ślipiński, Jarzembowski, Wang, Ren et Pang, 2017), comb. nov. [Brochocoleus]; genus Cionocups Kirejtshuk, gen. nov. with the type species: Cionocups manukyani sp. nov.; genus Echinocups Kirejtshuk et Jarzembowski, gen. nov. with the type species: Notocupes neli Tihelka, Huang et Cai, 2020 [Echinocups neli comb. nov.], and also Echinocups ohmkuhnlei (Jarzembowski, Wang et Zheng, 2020), comb. nov. [Notocupes] and Echinocups denticollis (Jiang, Li, Song, Shi, Liu, Chen et Kong, 2020), comb. nov. [Notocupes]; genus Jarzembowskops Kirejtshuk, gen. nov. with the type species: Brochocoleus caseyi Jarzembowski, Wang et Zheng, 2016 [Jarzembowskops caseyi comb. nov.]; genus Lobanovia Kirejtshuk, gen. nov. with the type species: Simmondsia permiana Ponomarenko, 2013 [Lobanovia permiana comb. nov.]; genus Pintolla Kirejtshuk, gen. nov. with the type species: Kaltanicupes ponomarenkoi Pinto, 1987 [Pintolla ponomarenkoi comb. nov.]; genus Polyakius Kirejtshuk, gen. nov. with the type species: Polyakius alberti Kirejtshuk, sp. nov. and Polyakius pubescens Kirejtshuk, sp. nov.; Clessidromma zengi Kirejtshuk, sp. nov.; Cupes golovatchi Kirejtshuk, sp. nov.; Cupes legalovi Kirejtshuk, sp. nov.; Cupes lutzi Kirejtshuk, sp. nov.; Cupes nabozhenkoi Kirejtshuk, sp. nov.; Cupes wedmannae Kirejtshuk, sp. nov.; Mallecupes prokini Kirejtshuk, sp. nov. and Omma janetae Kirejtshuk, sp. nov. The new synonymy is established for the generic names Clessidromma Jarzembowski, Wang et Zheng, 2017 and Lepidomma Jarzembowski, Wang et Zheng, 2019, syn. nov. The rank of Cainomerga A. Kirejtshuk, Nel et P. Kirejtshuk, 2016 is elevated from subgeneric to generic. Also other new combinations are proposed: Cainomerga brevicornis (A. Kirejtshuk, Nel et P. Kirejtshuk, 2016), comb. nov. [Mesocupes], Cainomerga fraterna (A. Kirejtshuk, Nel et P. Kirejtshuk, 2016), comb. nov. [Mesocupes], Cainomerga immaculata (Piton, 1940: 194), comb. nov. [Zonabris, Mesocupes], Cainomerga palaeocenica (A. Kirejtshuk, Nel et P. Kirejtshuk, 2016), comb. nov. [Mesocupes], and Cainomerga ponti (A. Kirejtshuk, Nel et P. Kirejtshuk, 2016), comb. nov. [Mesocupes], Clessidromma tianae (Jarzembowski, Wang et Zheng, 2019), comb. nov. [Lepidomma], Diluticupes applanatus (Tan et Ren, 2009), comb. nov. [Brochocoleus], Diluticupes crowsonae (Jarzembowski, Yan, Wang et Zhang. 2013), comb. nov. [Brochocoleus], Diluticupes magnus (Tan et Ren, 2009), comb. nov. [Brochocoleus], Diluticupes minor (Ponomarenko, 2000), comb. nov. [Brochocoleus], Diluticupes validus (Tan et Ren, 2009), comb. nov. [Brochocoleus], Diluticupes yangshuwanziensis (Jarzembowski, Yan, Wang et Zhang. 2013), comb. nov. [Brochocoleus], Monticupes curtinervis (Tan, Ren et Shih, 2007), comb. nov. [Tetraphalerus], Monticupes decorosus (Tan, Wang, Ren et Yang, 2012), comb. nov. [Tetraphalerus], Odontomma sulcatum (Tan, Ren et Shih, 2007), comb. nov. [Brochocoleus], Omma ancistrodontum (Tan, Wang, Ren et Yang, 2012), comb. nov. [Pareuryomma], Omma grande (Ponomarenko, 1964), comb. nov. [Tetraphalerus], Omma longicolle (Ponomarenko, 1997), comb. nov. [Tetraphalerus], Pareuryomma angustum (Tan, Ren et Shich, 2007), comb. nov. [Brochocoleus], Pareuryomma magnum (Tan et Ren, 2009), comb. nov. [Brochocoleus], Zygadenia aliena (Tan et Ren, 2006), comb. nov. [Ovatocupes], Zygadenia baojiatunensis (Hong 1992), comb. nov. [Chengdecupes], Zygadenia brachycephala (Ponomarenko, 1994), comb. nov. [Notocupes], Zygadenia caduca (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia caudata (Ponomarenko, 1966), comb. nov. [Notocupes], Zygadenia cellulosa (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia crassa (Ponomarenko, 1969), comb. nov., [Notocupes], Zygadenia cyclodontus (Tan, Ren, Shih et Ge, 2006), comb. nov. [Amblomma, Notocupes], Zygadenia dischdes (Zhang, 1986), comb. nov. [Notocupes], Notocupes dundulaensis (Ponomarenko, 1994), comb. nov. [Notocupes], Zygadenia elegans (Ponomarenko, 1994), comb. nov. [Notocupes], Zygadenia epicharis (Tan, Ren et Liu, 2005), comb. nov. [Amblomma, Notocupes], Zygadenia eumeura (Tan, Ren et Liu, 2005), comb. nov. [Amblomma, Notocupes], Zygadenia excellens (Ponomarenko, 1966), comb. nov. [Notocupes], Zygadenia exigua (Ponomarenko, 1994), comb. nov. [Notocupes], Zygadenia foersteri (Ponomarenko, 1971), comb. nov. [Procarabus, Notocupes], Zygadenia homora (Lin, 1986), comb. nov. [Conexicoxa, Notocupes], Zygadenia issykkulensis (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia jurassica (Hong 1983), comb. nov. [Chengdecupes], Zygadenia kezuoensis (Hong 1987), comb. nov. [Chengdecupes], Zygadenia khasurtuiensis (Strelnikova, 2019), comb. nov. [Notocupes], Zygadenia khetanensis (Ponomarenko, 1993), comb. nov. [Notocupes], Zygadenia kirghizica (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia laeta (Lin, 1976), [Tetraphalerus], Zygadenia laiyangensis (Hong et Wang, 1990), comb. nov. [Forticupes, Notocupes], Zygadenia lapidaria (Ponomarenko, 1968), comb. nov. [Notocupes], Zygadenia laticella (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia lata (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia lenta (Ren, Lu, Guo et Ji, 1995), comb. nov. [Tetraphalerus], Zygadenia lini (Ponomarenko, Yan, Wang et Zhang, 2012), comb. nov. [Notocupes], Zygadenia longicollis (Ponomarenko, 1994), comb. nov. [Notocupes], Zygadenia ludongensis (Wang et Liu, 1996), comb. nov. [Notocupes], Zygadenia minuscula (Tan, Ren, Shih et Ge, 2006), comb. nov. [Amblomma, Notocupes], Zygadenia mongolica (Ponomarenko, 1994), comb. nov. [Notocupes], Zygadenia nigrimonticola (Ponomarenko, 1968), comb. nov. [Notocupes], Zygadenia oxypyga (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia patula (Ponomarenko, 1985), comb. nov. [Notocupes], Zygadenia pingi (Ponomarenko et Ren, 2010), comb. nov. [Notocupes], Zygadenia porrecta (Tan, Ren, Shih et Ge, 2006), comb. nov. [Amblomma, Notocupes], Zygadenia protensa (Tan, Ren, Shih et Ge, 2006), comb. nov. [Amblomma, Notocupes], Zygodenia psilata (Tan, Ren et Liu, 2005), comb. nov. [Amblomma, Notocupes], , Zygadenia pulchra Ponomarenko, 1968, comb. nov. [Notocupes], Zygadenia reticulata (Oppenheim, 1888), comb. nov. [Procarabus, Notocupes], Notocupes rostrata (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia rudis (Tan, Ren et Liu, 2005), comb. nov. [Amblomma, Notocupes], Zygadenia shiluoensis (Hong 1984), comb. nov. [Chengdecupes], Zygadenia sogutensis (Ponomarenko, 1969), comb. nov., Zygadenia stabilis (Tan, Ren et Liu, 2005), comb. nov. [Amblomma, Notocupes], Zygadenia tenuis (Ponomarenko, 1969), comb. nov. [Notocupes], Zygadenia tripartita (Oppenheim, 1888), comb. nov. [Procarabus, Notocupes], Zygadenia tuanwangensis (Hong et Wang, 1990), comb. nov. [Picticupes, Notocupes], Zygadenia valida (Lin, 1976), comb. nov. [Sinocupes, Notocupes], Zygadenia vitimensis (Ponomarenko, 1966), comb. nov. [Notocupes]. Full article
(This article belongs to the Special Issue The Evolutionary History of the Coleoptera)
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Article
Reef Mapping Using Different Seabed Automatic Classification Tools
Geosciences 2020, 10(2), 72; https://doi.org/10.3390/geosciences10020072 - 15 Feb 2020
Cited by 4 | Viewed by 1771
Abstract
There is a great demand to develop new acoustic techniques to efficiently map the seabed and automate the interpretation of acoustic, sedimentological, and imaging data sets, eliminating subjectivity. Here, we evaluate the potential, limitations and complementariety of distinct supervised and automatic classification techniques [...] Read more.
There is a great demand to develop new acoustic techniques to efficiently map the seabed and automate the interpretation of acoustic, sedimentological, and imaging data sets, eliminating subjectivity. Here, we evaluate the potential, limitations and complementariety of distinct supervised and automatic classification techniques in the mapping of reefs by comparing these results with a reference map. The study was carried out in the Abrolhos Continental Shelf (Eastern Brazilian Continental Margin) using a multibeam echosounder and side scan sonar (SSS) dataset. Two automatic supervised techniques were applied. A reference map was derived by detailed manual interpretation carried out by three experts. The two supervised classification techniques were: benthic terrain modeler (BTM), a morphometric classification with focus on spatial analyses of the bathymetric grid derivatives, and object-based image analysis (OBIA), a segmentation applied to the backscatter data from the SSS mosaic. Both automatic techniques obtained similar values of reef coverage area, but overestimated the reef area when compared with the reference map. The agreement between BTM and OBIA results and the reference map was 69% and 67%, respectively. Disagreement was mainly due to quantity of reef (both methods over-estimated reef), while the disagreement in spatial allocation was relatively low, it indicates that both methods are reasonable representation of the spatial patterns of reef. Efficient mapping of reef in the wider area of the Abrolhos Continental Shelf will be best achieved by a further development of automatic methods tested against reference maps obained from representative areas of the seabed. By combining the results of the two automatic methods, it was possible to create an ensemble map, which achieved better agreement with the reference dataset. Full article
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Article
Cascading Dynamics of the Hydrologic Cycle in California Explored through Observations and Model Simulations
Geosciences 2020, 10(2), 71; https://doi.org/10.3390/geosciences10020071 - 14 Feb 2020
Cited by 4 | Viewed by 874
Abstract
As drought occurs in a region it can have cascading effects through the water cycle. In this study, we explore the temporal co-evolution of various components of the hydrologic cycle in California from 2002 to 2018. We combine information from the Gravity Recovery [...] Read more.
As drought occurs in a region it can have cascading effects through the water cycle. In this study, we explore the temporal co-evolution of various components of the hydrologic cycle in California from 2002 to 2018. We combine information from the Gravity Recovery and Climate Experiment (GRACE) satellites, the North American Land Data Assimilation System (NLDAS) suite of models, and the California Department of Water Resources (DWR) reservoir levels to analyze dynamics of Total Water Storage (TWS), soil moisture, snow pack, large reservoir storage, and ultimately, groundwater. For TWS, a trend of −2 cm/yr is observed during the entire time period of our analysis; however, this rate increases to about −5 cm/yr during drought periods (2006−2010 and 2012−2016). Results indicate that the majority of the loss in TWS is caused by groundwater depletion. Using proper error accounting, we are able to identify the start, the peak, and the ending of the drought periods for each individual water state variable in the study domain. We show that snow and soil moisture are impacted earlier and recover faster than surface water and groundwater. The annual and year-to-year dynamics shown in our results portray a clear cascading effect of the hydrologic cycle on the scale of 8−16 months. Full article
(This article belongs to the Special Issue Groundwater in arid and semiarid areas)
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Article
2D Runout Modelling of Hillslope Debris Flows, Based on Well-Documented Events in Switzerland
Geosciences 2020, 10(2), 70; https://doi.org/10.3390/geosciences10020070 - 14 Feb 2020
Cited by 5 | Viewed by 1028
Abstract
In mountain areas, mass movements, such as hillslope debris flows, pose a serious threat to people and infrastructure, although size and runout distances are often smaller than those of debris avalanches or in-channel-based processes like debris floods or debris flows. Hillslope debris-flow events [...] Read more.
In mountain areas, mass movements, such as hillslope debris flows, pose a serious threat to people and infrastructure, although size and runout distances are often smaller than those of debris avalanches or in-channel-based processes like debris floods or debris flows. Hillslope debris-flow events can be regarded as a unique process that generally can be observed at steep slopes. The delimitation of endangered areas and the implementation of protective measures are therefore an important instrument within the framework of a risk analysis, especially in the densely populated area of the alpine region. Here, two-dimensional runout prediction methods are helpful tools in estimating possible travel lengths and affected areas. However, not many studies focus on 2D runout estimations specifically for hillslope debris-flow processes. Based on data from 19 well-documented hillslope debris-flow events in Switzerland, we performed a systematic evaluation of runout simulations conducted with the software Rapid Mass Movement Simulation: Debris Flow (RAMMS DF)—a program originally developed for runout estimation of debris flows and snow avalanches. RAMMS offers the possibility to use a conventional Voellmy-type shear stress approach to describe the flow resistance as well as to consider cohesive interaction as it occurs in the core of dense flows with low shear rates, like we also expect for hillslope debris-flow processes. The results of our study show a correlation between the back-calculated dry Coulomb friction parameters and the percentage of clay content of the mobilised soils. Considering cohesive interaction, the performance of all simulations was improved in terms of reducing the overestimation of the observed deposition areas. However, the results also indicate that the parameter which accounts for cohesive interaction can neither be related to soil physical properties nor to different saturation conditions. Full article
(This article belongs to the Special Issue Numerical Modeling of Surface Processes)
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Article
Simple Particle Model for Low-Density Granular Flow Interacting with Ambient Fluid
Geosciences 2020, 10(2), 69; https://doi.org/10.3390/geosciences10020069 - 13 Feb 2020
Cited by 1 | Viewed by 755
Abstract
To understand the time evolutions of frontal speed and shape in a low-density granular flow, we propose a simple particle model. This model solves the equation of motion for each particle and simulates the time evolution of low-density granular flow. Spherical particles constituting [...] Read more.
To understand the time evolutions of frontal speed and shape in a low-density granular flow, we propose a simple particle model. This model solves the equation of motion for each particle and simulates the time evolution of low-density granular flow. Spherical particles constituting a low-density granular flow slide on a slope at a steeper angle than the angle of repose. The particle motion is determined based on three forces: gravity as the driving force, repulsive force due to particle collision, and drag force due to the particle interaction through the ambient fluid. Two-dimensional numerical simulations of this model are conducted on the slope: the xy plane parallel to the slope and the xz plane perpendicular to the slope. In the xy plane, particles aggregate at the moving front of the granular flow, and subsequently, flow instability occurs as a wavy pattern. This flow pattern is caused by the interparticle interaction arising from the drag force. Additionally, a vortex convection of particles is formed inside the aggregations. Simultaneously, particle aggregation is also found at the moving front of the granular flow in the xz plane. The aggregation resembles a head–tail structure, where the frontal angle against the slope approaches 60 from a larger angle as time progresses. Comparing the numerical result by varying the particle size reveals that the qualitative dynamics of the granular flow are independent of particle size. Although the model is not realistic, our study presents a new particle-based approach that elucidates the dynamics of low-density granular flow. Full article
(This article belongs to the Special Issue Snow Avalanche Dynamics)
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Article
Distinguishing between Deep-Water Sediment Facies: Turbidites, Contourites and Hemipelagites
Geosciences 2020, 10(2), 68; https://doi.org/10.3390/geosciences10020068 - 13 Feb 2020
Cited by 23 | Viewed by 2811
Abstract
The distinction between turbidites, contourites and hemipelagites in modern and ancient deep-water systems has long been a matter of controversy. This is partly because the processes themselves show a degree of overlap as part of a continuum, so that the deposit characteristics also [...] Read more.
The distinction between turbidites, contourites and hemipelagites in modern and ancient deep-water systems has long been a matter of controversy. This is partly because the processes themselves show a degree of overlap as part of a continuum, so that the deposit characteristics also overlap. In addition, the three facies types commonly occur within interbedded sequences of continental margin deposits. The nature of these end-member processes and their physical parameters are becoming much better known and are summarised here briefly. Good progress has also been made over the past decade in recognising differences between end-member facies in terms of their sedimentary structures, facies sequences, ichnofacies, sediment textures, composition and microfabric. These characteristics are summarised here in terms of standard facies models and the variations from these models that are typically encountered in natural systems. Nevertheless, it must be acknowledged that clear distinction is not always possible on the basis of sedimentary characteristics alone, and that uncertainties should be highlighted in any interpretation. A three-scale approach to distinction for all deep-water facies types should be attempted wherever possible, including large-scale (oceanographic and tectonic setting), regional-scale (architecture and association) and small-scale (sediment facies) observations. Full article
(This article belongs to the Special Issue Interacting Alongslope and Downslope Sedimentary Processes)
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Article
Bacterial Communities of Novaya Zemlya Archipelago Ice and Permafrost
Geosciences 2020, 10(2), 67; https://doi.org/10.3390/geosciences10020067 - 12 Feb 2020
Cited by 4 | Viewed by 1449
Abstract
The study of bacterial communities associated with extreme ecosystems is one of the most important tasks in modern microbial ecology. Despite a large number of studies being performed, the ecosystems that have not been sufficiently explored from the microbiological point of view still [...] Read more.
The study of bacterial communities associated with extreme ecosystems is one of the most important tasks in modern microbial ecology. Despite a large number of studies being performed, the ecosystems that have not been sufficiently explored from the microbiological point of view still exist. Such research is needed for improving the understanding of the limits and mechanisms of bacterial survival under extreme conditions, and for revealing previously undescribed species and their role in global biospheric processes and their functional specifics. The results of the complex microbiological characteristics of permafrost and ice—collected on the Severniy Island in the northern part of the Novaya Zemlya archipelago—which have not previously been described from microbiological point of view, are presented in this article. The analysis included both culture-independent and culture-dependent methods, in particular, the spectra of metabolic activity range analysis in vitro under different temperature, pH and salinity conditions. High values for the total number of prokaryotes in situ (1.9 × 108–3.5 × 108 cells/g), a significant part of which was able to return to a metabolically active state after thawing, and moderate numbers of culturable bacteria (3.3 × 106–7.8 × 107 CFU/g) were revealed. Representatives of Proteobacteria, Actinobacteria, and Bacteroidetes were dominant in situ; Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes were the most abundant phyla in vitro. Physiological assays revealed the mesophilic and neutrophilic optima of temperature and pH of culturing conditions, respectively, and wide temperature and pH ranges of culturable communities’ reproduction activity. Isolated strains were characterized by moderate halotolerant properties and antibiotic resistance, including multiple antibiotic resistance. It was found that almost all cultured bacterial diversity revealed (not just a few resistant species) had extremotolerant properties regarding a number of stress factors. This indicates the high adaptive potential of the studied microbial communities and their high sustainability and capability to retain functional activity under changing environmental (including climatic) conditions in wide ranges. Full article
(This article belongs to the Section Biogeosciences)
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Article
On Including Near-surface Zone Anisotropy for Static Corrections Computation—Polish Carpathians 3D Seismic Processing Case Study
Geosciences 2020, 10(2), 66; https://doi.org/10.3390/geosciences10020066 - 11 Feb 2020
Cited by 1 | Viewed by 755
Abstract
Obtaining the most accurate and detailed subsurface information from seismic surveys is one of the main challenges for seismic data processing, especially in the context of complex geological conditions (e.g., mountainous areas). The correct calculation of static corrections allows for the reliable processing [...] Read more.
Obtaining the most accurate and detailed subsurface information from seismic surveys is one of the main challenges for seismic data processing, especially in the context of complex geological conditions (e.g., mountainous areas). The correct calculation of static corrections allows for the reliable processing of seismic data. This, in turn, leads to better geological interpretation. A seismic signal passing through a near-surface zone (NSZ) is adversely affected by the high heterogeneity of this zone. As a result of this, observed travel times often show anisotropy. The application of refractive waves and the time delay solution without taking into account the effects caused by the complex anisotropy of an NSZ does not meet the standards of modern seismic surveys. The construction of the NSZ model in mountain regions with the use of refraction may be extremely difficult, as the vertical layers can be observed very close to the surface. It is not sufficient to apply regular isotropic refractive solutions in such conditions. The presented studies show the results of taking into account the anisotropy of an NSZ in the calculations of static corrections. The presented results show that this step is critical for the detailed processing of three-dimensional (3D) seismic data collected in the difficult region of the Carpathians in Southern Poland. Full article
(This article belongs to the Section Geophysics)
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Article
Hydrostratigraphic Characterisation of Shallow Coastal Aquifers of Eastern Dahomey Basin, S/W Nigeria, Using Integrated Hydrogeophysical Approach; Implication for Saltwater Intrusion
Geosciences 2020, 10(2), 65; https://doi.org/10.3390/geosciences10020065 - 09 Feb 2020
Cited by 3 | Viewed by 849
Abstract
This study employed electrical resistivity tomography (ERT) in characterising the shallow groundwater aquifers of Eastern Dahomey basin in southwestern Nigeria to assess the possible occurrence and distribution of saltwater within the aquifers. Electrical resistivity tomography (ERT), induced polarization (IP) and borehole logging were [...] Read more.
This study employed electrical resistivity tomography (ERT) in characterising the shallow groundwater aquifers of Eastern Dahomey basin in southwestern Nigeria to assess the possible occurrence and distribution of saltwater within the aquifers. Electrical resistivity tomography (ERT), induced polarization (IP) and borehole logging were carried in locations with relatively enhanced electrical conductivity (EC) within the coastal zone of the basin through 97 groundwater samples from shallow wells and boreholes; 500 m-length ERT and IP sections were carried out along three traverses A–B, C–D and E–F in directions perpendicular and parallel to the coastline. Three geoelectrical layers were identified along traverse line A–B which comprises cross-sections 1, 2, 3 and 4 located around Ugbonla, Aboto and Igbokoda with layers’ resistivity and chargeability values ranging from (1–1000, 33–200 and 1–1700 Ωm), and (−50–200 Ωm, −30–200 Ωm and −50–120 Ωm, respectively, from the top to the bottom layer. These values indicated unconsolidated sand/lateritic silty clay, underlain by a sandy/silty clay layer with underlying fine-grained sand with disseminated clay lenses. The average thickness of the first two layers was 16 and 53 m while that of the third layer was undetermined. Resistivity and chargeability results from ERT and IP cross-sections along profile C–D exhibited characteristics similar to that of profile A–B with unconsolidated sands which were underlain by intercalation of sandy/silty clay and fine-grained sands with suspected clay lenses saturated with saline water. Profile E–F revealed a geoelectrical layer with low resistivity which ranged from 1–30 Ωm with the corresponding chargeability between −150–400 ms. This indicated a saline water-saturated layer of fine-grained sand and silty clay which is overlaid by the unconsolidated unconfined freshwater aquifer. Correlation of selected ERT results with borehole logs further affirmed the suspected lithology from the sections. Two scenarios of saltwater intrusions into coastal freshwater aquifer were suggested which include the presence of trapped salt-saturated clay lenses within aquifer lithology and seawater incursion induced by over-drafting of groundwater in this basin.Therefore, it identified the need for further investigation which will involve a combination of hydrochemical and isotopes to further understand the paleowater hypothesis. Full article
(This article belongs to the Special Issue Urban Geophysics)
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Article
Geostructural and Geomechanical Study of the Piastrone Quarry (Seravezza, Italy) Supported by Photogrammetry to Assess Failure Mode
Geosciences 2020, 10(2), 64; https://doi.org/10.3390/geosciences10020064 - 08 Feb 2020
Viewed by 993
Abstract
The use of non-contact-techniques for rock mass characterization has been growing significantly over the last decade. However, their application to stability assessment of ornamental stone has not yet received much attention from researchers. This study utilizes rock mass data both in terms of [...] Read more.
The use of non-contact-techniques for rock mass characterization has been growing significantly over the last decade. However, their application to stability assessment of ornamental stone has not yet received much attention from researchers. This study utilizes rock mass data both in terms of slope orientations and degree of fracturing obtained from a point cloud, a set of three-dimensional (3D) points representing a rock mass surface, to (1) investigate the influence of geostructures at different scales and (2) assess quarry stability by determining areas susceptible to different failure types. Multi-resolution point clouds are obtained through several photogrammetric survey techniques to identify important structural elements of the site. By integrating orientation data of discontinuity planes, obtained with a traditional survey, and of traces, outlined on point clouds, several joint sets were identified. Kinematic tests revealed various potential failure modes of the rock slope. Moreover, an analysis of the influence of the discontinuity strength determined by the presence of rock bridges was carried out. The study revealed that the strength of the quarry face is governed by the presence of rock bridges that act to improve the stability condition of the rock fronts. Full article
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Article
Geochemical Discrimination of Monazite Source Rock Based on Machine Learning Techniques and Multinomial Logistic Regression Analysis
Geosciences 2020, 10(2), 63; https://doi.org/10.3390/geosciences10020063 - 06 Feb 2020
Cited by 5 | Viewed by 1250
Abstract
Detrital monazite geochronology has been used in provenance studies. However, there are complexities in the interpretation of age spectra due to their wide occurrence in both igneous and metamorphic rocks. We use the multinomial logistic regression (MLR) and cross-validation (CV) techniques to establish [...] Read more.
Detrital monazite geochronology has been used in provenance studies. However, there are complexities in the interpretation of age spectra due to their wide occurrence in both igneous and metamorphic rocks. We use the multinomial logistic regression (MLR) and cross-validation (CV) techniques to establish a geochemical discrimination of monazite source rocks. The elemental abundance-based geochemical discrimination was tested by selecting 16 elements from granitic and metamorphic rocks. The MLR technique revealed that light rare earth elements (REEs), Eu, and some heavy REEs are important discriminators that reflect elemental fractionation during magmatism and/or metamorphism. The best model yielded a discrimination rate of ~97%, and the CV method validated this approach. We applied the discrimination model to detrital monazites from African rivers. The detrital monazites were mostly classified as granitic and of garnet-bearing metamorphic origins; however, their proportion of metamorphic origin was smaller than the proportion that was obtained by using the elemental-ratio-based discrimination proposed by Itano et al. in Chemical Geology (2018). Considering the occurrence of metamorphic rocks in the hinterlands and the different age spectra between monazite and zircon in the same rivers, a ratio-based discrimination would be more reliable. Nevertheless, our study demonstrates the advantages of machine-learning-based approaches for the quantitative discrimination of monazite. Full article
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Article
Naturally Occurring Potentially Harmful Elements in Groundwater in Makueni County, South-Eastern Kenya: Effects on Drinking Water Quality and Agriculture
Geosciences 2020, 10(2), 62; https://doi.org/10.3390/geosciences10020062 - 06 Feb 2020
Viewed by 1085
Abstract
Makueni County is located in the semi-arid south-eastern Kenya region characterized by unreliable rainfall and limited surface water resources. This necessitates a high reliance on groundwater for domestic and agricultural use. In this paper, we report on the physico-chemical characteristics of 20 drinking [...] Read more.
Makueni County is located in the semi-arid south-eastern Kenya region characterized by unreliable rainfall and limited surface water resources. This necessitates a high reliance on groundwater for domestic and agricultural use. In this paper, we report on the physico-chemical characteristics of 20 drinking water sources (boreholes, shallow wells, streams, and tap water) collected during the dry season (November 2018), the geochemical processes controlling their composition, and their suitability for drinking water and irrigation. Of all the physico-chemical parameters analysed, the concentrations of total dissolved solids, hardness, electrical conductivity, magnesium, calcium, chloride, and fluoride exceeded the permissible drinking water limits set by both the World Health Organization (WHO) and Kenya Bureau of Standards (KEBS) in up to 55% of the samples. The dominant ions reflect the high salinity in the water that ranged from very high to extreme in up to 50% of samples. The northern region shows the highest concentrations of the dominant parameters. The water type is predominantly Ca-Mg-HCO3 with a trend to Ca-Mg-Cl-SO4. Rock weathering and evaporation are suggested to be the primary controls of groundwater geochemical characteristics. High salinity and fluoride, which are associated with reported undesirable taste and gastrointestinal upsets, as well as cases of dental fluorosis are some of the effects of consuming groundwater in the region. These two parameters can be attributed to the weathering of biotite gneisses, granitoid gneisses, migmatites, and basaltic rocks that occur in the area. The high salinity and alkalinity of most of the samples analysed, renders the water unsuitable for irrigation in the study area. Full article
(This article belongs to the Special Issue Perspectives on Environment and Human Health)
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Comment
A Note on “Metal Distribution and Short-Time Variability in Recent Sediments from the Ganges River towards the Bay of Bengal (India)” by Bonnail et al. (2019)
Geosciences 2020, 10(2), 61; https://doi.org/10.3390/geosciences10020061 - 05 Feb 2020
Cited by 1 | Viewed by 903
Abstract
A careful reading of Bonnail et al. (2019)’s work points out some issues in the description of the Ganges River, e.g., describing it in a way that gives impression to the readers unfamiliar with the Indian rivers that it flows by the national [...] Read more.
A careful reading of Bonnail et al. (2019)’s work points out some issues in the description of the Ganges River, e.g., describing it in a way that gives impression to the readers unfamiliar with the Indian rivers that it flows by the national capital New Delhi, after reading “it receives inputs from highly populated cities of India, including New Delhi and …”. However, as a matter of fact, it is not the Ganges, but the Yamuna River, a tributary of the Ganges, that passes through the National Capital Region of Delhi. Moreover, authors identify the studied river as the Ganges, whereas it is one of the distributaries of the Ganges called Hooghly (anglicized version of its local name Hugli). They have referred to the seasonality of the studied river; however, the flow of the studied (Hooghly) river is controlled by a barrage on the Ganges River. Moreover, Hooghly River receives input from its own tributaries; viz., Mayurakshi and Damodar, flowing through highly mineralized and coaliferous areas of Jharkhand state of India. Bonnail et al. (2019) have attributed the contamination of the river sediments to anthropogenic activities alone, by not evaluating likely natural sources. A correction factor for the underestimated total organic carbon (TOC) content obtained using Walkley-Black method should have been applied before using TOC values for factor analysis to overcome the underestimation issue with this method. This work intends to serve as a compendium, rather than a critique, to otherwise commendable work by Bonnail et al. (2019). Full article
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Article
The Undrained Behaviour of an Air-Fall Volcanic Ash
Geosciences 2020, 10(2), 60; https://doi.org/10.3390/geosciences10020060 - 05 Feb 2020
Cited by 3 | Viewed by 740
Abstract
Pyroclastic soils are widespread in the world. In particular, they cover a great part of Campania, a densely populated country of Southern Italy, where some distinct volcanic centers are present. In these soils, precipitations can trigger fast flow-like landslides causing destruction and loss [...] Read more.
Pyroclastic soils are widespread in the world. In particular, they cover a great part of Campania, a densely populated country of Southern Italy, where some distinct volcanic centers are present. In these soils, precipitations can trigger fast flow-like landslides causing destruction and loss of human lives. The movement style, the high velocity and the long run-out of these landslides are an indication of the occurrence, in the saturated soil mass, of mechanisms of undrained instability due to the inability of soil to sustain the deviator stress related to the slope condition. This paper reports the results of a wide experimental laboratory program carried out on a volcanic ash, which recently has been the seat of a killer landslide, stressing the factors that govern the undrained response of these materials. Full article
(This article belongs to the Special Issue Innovative Strategies for Sustainable Mitigation of Landslide Risk)
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Article
Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies
Geosciences 2020, 10(2), 59; https://doi.org/10.3390/geosciences10020059 - 04 Feb 2020
Cited by 2 | Viewed by 1139
Abstract
The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, [...] Read more.
The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests and a flushing process to evaluate the adsorption and desorption capacities of the zeolite. In the column experiments, the samples were subjected to eight successive cycles involving the percolation of a potassium aqueous solution (1500 mg/L) and a subsequent flushing process with water. Batch tests were conducted by mixing 20 g of zeolite with 100 mL of single-element aqueous solutions of K and Zn with concentrations of 200 mg/L. The results indicate that the zeolite rock is composed predominantly of clinoptilolite species and has a Si/Al ratio of 6.8, a high cationic exchange capacity (CEC) of 180 cmolc/kg and a high K+ adsorption rate with a removal efficiency of 78%. The adsorption isotherms of the zeolite follow the Langmuir model and are well fit by a pseudo-second-order kinetic model showing a high correlation coefficient (r2 > 0.999) for both K+ and Zn2+ cations. Additionally, the contaminant transport parameters for K+ ions (Rd = 24.9; Dh = 1.32 × 10–2 cm2/s and α = 1.42) reveal that the zeolite is resistant to the dispersion of ions in the barrier, indicating that the material has advantageous characteristics for use in a PRB. However, the flushing process of the material is not efficient, indicating that the appropriate use of the zeolite is in clean-up systems in which the adsorbent material can be exchanged after losing its efficiency as a reactive barrier. Full article
(This article belongs to the Section Hydrogeology)
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Editorial
New Perspectives in the Definition/Evaluation of Seismic Hazard through Analysis of the Environmental Effects Induced by Earthquakes
Geosciences 2020, 10(2), 58; https://doi.org/10.3390/geosciences10020058 - 04 Feb 2020
Cited by 1 | Viewed by 1083
Abstract
The application of the Environmental Seismic Intensity (ESI) scale 2007 to moderate and strong earthquakes, in different geological context all over the word, highlights the importance of Earthquake Environmental Effects (EEEs) for the assessment of seismic hazards. This Special Issue “New Perspectives in [...] Read more.
The application of the Environmental Seismic Intensity (ESI) scale 2007 to moderate and strong earthquakes, in different geological context all over the word, highlights the importance of Earthquake Environmental Effects (EEEs) for the assessment of seismic hazards. This Special Issue “New Perspectives in the Definition/Evaluation of Seismic Hazard through Analysis of the Environmental Effects Induced by Earthquakes” presents a collection of scientific contributions that provide a sample of the state-of-the-art in this field. Moreover the collected papers also analyze new data produced with multi-disciplinary and innovative methods essential for development of new seismic hazard models. Full article
Article
Hazards of Activation of Cryogenic Processes in the Arctic Community: A Geopenetrating Radar Study in Lorino, Chukotka, Russia
Geosciences 2020, 10(2), 57; https://doi.org/10.3390/geosciences10020057 - 04 Feb 2020
Cited by 2 | Viewed by 910
Abstract
The subsurface structure of permafrost is of high significance to forecast landscape dynamics and the engineering stability of infrastructure under human impacts and climate warming, which is a modern challenge for Arctic communities. Application of the non-destructive method of geo-penetrating radar (GPR) survey [...] Read more.
The subsurface structure of permafrost is of high significance to forecast landscape dynamics and the engineering stability of infrastructure under human impacts and climate warming, which is a modern challenge for Arctic communities. Application of the non-destructive method of geo-penetrating radar (GPR) survey is a promising way to study it. The study program, which could be used for planning and monitoring of measures of adaptation of Arctic communities to environmental changes is provided in this paper. The main principle was to use etalons of coupled radargrams and archive geological data to interpret changes in the permafrost structure from a grid of 5–10 m deep GPR transects. Here, we show the application of GPR to reconstruct and predict hazards of activation of cryogenic processes from the spatial variability in the structure of permafrost. The cumulative effects of the village and climate change on permafrost were manifested in changes in the active layer thickness from 0.5−1.0 m to up to 3.5 m. Despite that the permafrost degradation has declined due to the improved maintenance of infrastructure and the effects of ground filling application, the hazards of heaving and thermokarst remain for the built-up area in Lorino. Full article
(This article belongs to the Section Natural Hazards)
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Article
Geochronology and Stable Isotope Analysis of Fracture-Fill and Karst Mineralization Reveal Sub-Surface Paleo-Fluid Flow and Microbial Activity of the COSC-1 Borehole, Scandinavian Caledonides
Geosciences 2020, 10(2), 56; https://doi.org/10.3390/geosciences10020056 - 03 Feb 2020
Cited by 4 | Viewed by 1049
Abstract
The deep biosphere hosted in fractured rocks within the upper continental crust is one of the least understood and studied ecological realms on Earth. Scarce knowledge of ancient life and paleo-fluid flow within this realm is owing to the lack of deep drilling [...] Read more.
The deep biosphere hosted in fractured rocks within the upper continental crust is one of the least understood and studied ecological realms on Earth. Scarce knowledge of ancient life and paleo-fluid flow within this realm is owing to the lack of deep drilling into the crust. Here we apply microscale high spatial-resolution analytical techniques to fine-grained secondary minerals in a deep borehole (COSC-1) drilled into the Silurian-Devonian Scandinavian Caledonide mountain range in central Sweden. The aim is to detect and date signs of ancient microbial activity and low-temperature fluid circulation in micro-karsts (foliation-parallel dissolution cavities in the rock) and fractures at depth in the nappe system. Vein carbonates sampled at 684 to 2210 m show a decreased C isotope variability at depths below 1050 m; likely due to decreased influence of organic-C at great depth. Micro-karsts at 122–178 m depth feature at least two generations of secondary calcite and pyrite growth in the voids as shown by secondary ion mass spectrometry analytical transects within individual grains. The younger of these two precipitation phases shows 34S-depleted δ34Spyrite values (−19.8 ± 1.6‰ vs. Vienna-Canyon Diablo Troilite (V-CDT)) suggesting microbial sulfate reduction in situ. The calcite of this late phase can be distinguished from the older calcite by higher δ18Ocalcite values that correspond to precipitation from ambient meteoric water. The late stage calcite gave two separate laser ablation inductively coupled mass spectrometry-derived U-Pb ages (9.6 ± 1.3 Ma and 2.5 ± 0.2 Ma), marking a minimum age for widespread micro-karst formation within the nappe. Several stages of fluid flow and mineral precipitation followed karst formation; with related bacterial activity as late as the Neogene-Quaternary; in structures presently water conducting. The results show that our combined high spatial-resolution stable isotope and geochronology approach is suitable for characterizing paleo-fluid flow in micro-karst; in this case, of the crystalline crust comprising orogenic nappe units. Full article
(This article belongs to the Special Issue Tracking the Deep Biosphere through Time)
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