Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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17 pages, 4515 KiB  
Article
Near-Surface Geophysical Characterization of Lithologies in Corfu and Lefkada Towns (Ionian Islands, Greece)
Geosciences 2022, 12(12), 446; https://doi.org/10.3390/geosciences12120446 - 03 Dec 2022
Cited by 2 | Viewed by 1803
Abstract
Lefkada and Corfu old towns are located in the western part of Greece, in the Ionian Sea. Their proximity to the Hellenic subduction zone (HSZ) is the reason for their intense seismicity. The main goal of this study was the estimation of the [...] Read more.
Lefkada and Corfu old towns are located in the western part of Greece, in the Ionian Sea. Their proximity to the Hellenic subduction zone (HSZ) is the reason for their intense seismicity. The main goal of this study was the estimation of the geotechnical characteristics of the subsurface, with the contribution of applied geophysical techniques. Therefore, seismic refraction tomography (SRT) and multichannel analysis of surface waves (MASW) were applied. A total of thirty-three (33) seismic and geoelectrical profiles were performed in both towns in order to evaluate the geotechnical characteristics of the subsurface formations. Additionally, subsurface resistivity distributions were investigated with the application of electrical resistivity tomography (ERT). Some important elastic moduli were calculated through the combination of estimated seismic wave velocities and laboratory density measurements. The horizontal distribution of seismic velocities and mechanical properties (σ, E, K, G) of Corfu town was illustrated in maps, for the depth of 5 m. The geophysical interpretation also revealed that Lefkada’s subsurface consists of only one compact geological formation, with little or no variation of its geophysical-geotechnical characteristics. Beyond that, the ground type classifications for the two towns were determined according to the European Committee for Standardization Eurocode 8, based on VS30 values. Full article
(This article belongs to the Special Issue Recent Advances in Surface Wave Imaging)
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46 pages, 8683 KiB  
Article
Development and Dynamics of Sediment Waves in a Complex Morphological and Tidal Dominant System: Southern Irish Sea
Geosciences 2022, 12(12), 431; https://doi.org/10.3390/geosciences12120431 - 23 Nov 2022
Cited by 6 | Viewed by 2618
Abstract
With the recent push for a transition towards a climate-resilient economy, the demand on marine resources is accelerating. For many economic exploits, a comprehensive understanding of environmental parameters underpinning seabed morphodynamics in tidally-dominated shelf seas, and the relationship between local and regional scale [...] Read more.
With the recent push for a transition towards a climate-resilient economy, the demand on marine resources is accelerating. For many economic exploits, a comprehensive understanding of environmental parameters underpinning seabed morphodynamics in tidally-dominated shelf seas, and the relationship between local and regional scale sediment transport regimes as an entire system, is imperative. In this paper, high-resolution, time-lapse bathymetry datasets, hydrodynamic numerical modelling outputs and various theoretical parameters are used to describe the morphological characteristics of sediment waves and their spatio-temporal evolution in a hydrodynamically and morphodynamically complex region of the Irish Sea. Analysis reveals sediment waves in a range of sizes (height = 0.1 to 25.7 m, and wavelength = 17 to 983 m), occurring in water depths of 8.2 to 83 mLAT, and migrating at a rate of 1.1 to 79 m/yr. Combined with numerical modelling outputs, a strong divergence of sediment transport pathways from the previously understood predominantly southward flow in the south Irish Sea is revealed, both at offshore sand banks and independent sediment wave assemblages. This evidence supports the presence of a semi-closed circulatory hydrodynamic and sediment transport system at Arklow Bank (an open-shelf linear sand bank). Contrastingly, the Lucifer–Blackwater Bank complex and associated sediment waves are heavily influenced by the interaction between a dominant southward flow and a residual headland eddy, which also exerts a strong influence on the adjacent banner bank. Furthermore, a new sediment transfer system is defined for offshore independent sediment wave assemblages, whereby each sediment wave field is supported by circulatory residual current cells originating from offshore sand banks. These new data and results improve knowledge of seabed morphodynamics in tidally-dominated shelf seas, which has direct implications for offshore renewable developments and long-term marine spatial planning. Full article
(This article belongs to the Special Issue Seabed Morphodynamics)
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26 pages, 12690 KiB  
Review
Why Engineers Should Not Attempt to Quantify GSI
Geosciences 2022, 12(11), 417; https://doi.org/10.3390/geosciences12110417 - 11 Nov 2022
Cited by 7 | Viewed by 2477
Abstract
In the past decade, there has been an increasing trend of digitalizing rock engineering processes. However, this process has not been accompanied by a critical analysis of the very same empirical methods that many complex numerical and digital methods are founded upon. As [...] Read more.
In the past decade, there has been an increasing trend of digitalizing rock engineering processes. However, this process has not been accompanied by a critical analysis of the very same empirical methods that many complex numerical and digital methods are founded upon. As engineers, we are taught to use and trust numbers. Indeed, we would not be able to define the factor of the safety of a structure without numbers. However, what happens when those numbers are nothing but numerical descriptions of qualitative assessments? In this paper we present a critical review of the many attempts presented in the literature to quantify GSI (geological strength index). To the authors’ knowledge, this paper represents the first time that all the different GSI tables and quantification methods that have been proposed over the past two decades are collated and compared critically. In our critique, we argue against the paradigm whereby the quantification process adds the experience factor for inexperienced engineers. Furthermore, we discuss the limitations of the notion that GSI quantification methods could transform subjectivity into objectivity since the parameters under considerations are not quantitative measurements. Relying on empirically defined quantitative equivalences raises important questions, particularly when these quantitative equivalences are being used to define so-called accurate rock mass classification input for design purposes. Full article
(This article belongs to the Collection New Advances in Geotechnical Engineering)
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11 pages, 2590 KiB  
Review
Shoreline Change Analysis along Rivers and Deltas: A Systematic Review and Bibliometric Analysis of the Shoreline Study Literature from 2000 to 2021
Geosciences 2022, 12(11), 410; https://doi.org/10.3390/geosciences12110410 - 08 Nov 2022
Cited by 3 | Viewed by 1924
Abstract
Globally, coastal zones, rivers and riverine areas, and deltas carry enormous values for ecosystems, socio-economic, and environmental perspectives. These often highly populated areas are generally significantly different from interior hinterlands in terms of population density, economic activities, and geophysical and ecological processes. Geospatial [...] Read more.
Globally, coastal zones, rivers and riverine areas, and deltas carry enormous values for ecosystems, socio-economic, and environmental perspectives. These often highly populated areas are generally significantly different from interior hinterlands in terms of population density, economic activities, and geophysical and ecological processes. Geospatial technologies are widely used by scholars from multiple disciplines to understand the dynamic nature of shoreline changes globally. In this paper, we conduct a systematic literature review to identify and interpret research patterns and themes related to shoreline change detection from 2000 to 2021. Two databases, Web of Science and Scopus, were used to identify articles that investigate shoreline change analysis using geospatial technique such as remote sensing and GIS analysis capabilities (e.g., the Digital Shoreline Analysis System (DSAS). Between the years 2000 and 2021, we initially found 1622 articles, which were inspected for suitability, leading to a final set of 905 articles for bibliometric analysis. For systematic analysis, we used Rayyan—a web-based platform used for screening literature. For bibliometric network analysis, we used the CiteSpace, Rayyan, and VOSviewer software. The findings of this study indicate that the majority of the literature originated in the USA, followed by India. Given the importance of protecting the communities living in the riverine areas, coastal zones, and delta regions, it is necessary to ask new research questions and apply cutting-edge tools and technology, such as machine learning approach and GeoAI, to fill the research gaps on shoreline change analysis. Such approaches could include, but are not limited to, centimeter level accuracy with high-resolution satellite imagery, the use of unmanned aerial vehicles (UAV), and point cloud data for both local and global level shoreline change and analysis. Full article
(This article belongs to the Special Issue Shoreline Dynamics and Beach Erosion, 2nd Edition)
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12 pages, 8895 KiB  
Article
On Two Formulations of Polar Motion and Identification of Its Sources
Geosciences 2022, 12(11), 398; https://doi.org/10.3390/geosciences12110398 - 26 Oct 2022
Cited by 11 | Viewed by 11929
Abstract
Differences in formulation of the equations of celestial mechanics may result in differences in interpretation. This paper focuses on the Liouville-Euler system of differential equations as first discussed by Laplace. In the “modern” textbook presentation of the equations, variations in polar motion and [...] Read more.
Differences in formulation of the equations of celestial mechanics may result in differences in interpretation. This paper focuses on the Liouville-Euler system of differential equations as first discussed by Laplace. In the “modern” textbook presentation of the equations, variations in polar motion and in length of day are decoupled. Their source terms are assumed to result from redistribution of masses and torques linked to Earth elasticity, large earthquakes, or external forcing by the fluid envelopes. In the “classical” presentation, polar motion is governed by the inclination of Earth’s rotation pole and the derivative of its declination (close to length of day, lod). The duration and modulation of oscillatory components such as the Chandler wobble is accounted for by variations in polar inclination. The “classical” approach also implies that there should be a strong link between the rotations and the torques exerted by the planets of the solar system. Indeed there is, such as the remarkable agreement between the sum of forces exerted by the four Jovian planets and components of Earth’s polar motion. Singular Spectral Analysis of lod (using more than 50 years of data) finds nine components, all with physical sense: first comes a “trend”, then oscillations with periods of ∼80 yrs (Gleissberg cycle), 18.6 yrs, 11 yrs (Schwabe), 1 year and 0.5 yr (Earth revolution and first harmonic), 27.54 days, 13.66 days, 13.63 days and 9.13 days (Moon synodic period and harmonics). Components with luni-solar periods account for 95% of the total variance of the lod. We believe there is value in following Laplace’s approach: it leads to the suggestion that all the oscillatory components with extraterrestrial periods (whose origin could be found in the planetary and solar torques), should be present in the series of sunspots and indeed, they are. Full article
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15 pages, 4565 KiB  
Article
A Reappraisal of the Destructive Earthquake (Mw5.9) of 15 July 1909 in Western Greece
Geosciences 2022, 12(10), 374; https://doi.org/10.3390/geosciences12100374 - 10 Oct 2022
Cited by 3 | Viewed by 1806
Abstract
Studies on earthquakes that occurred in the early instrumental period of seismology are of importance for the seismic hazard assessment and are still under investigation since new data are being increasingly revealed. We study the case of a moderate-to-strong earthquake that occurred on [...] Read more.
Studies on earthquakes that occurred in the early instrumental period of seismology are of importance for the seismic hazard assessment and are still under investigation since new data are being increasingly revealed. We study the case of a moderate-to-strong earthquake that occurred on 15 July 1909 in NW Peloponnese, Greece. Although the earthquake event was quite destructive, it remains little-known so far in the seismological tradition. We compiled a variety of documentary sources and showed that the earthquake caused extensive building destruction in Chavari and in many other villages with an estimated maximum intensity IX (in EMS-98 scale) and a death toll as high as 55. We also assigned macroseismic intensities in several observation points and drew isoseismal lines by applying the nearest-neighbor technique. From empirical relationships between magnitude and intensities, we estimated the macroseismic magnitude of proxy Ms5.9. Our examination also revealed a variety of earthquake associated phenomena including several types of precursors and abundant co-seismic hydrological changes and ground failures, such as soil liquefaction, surface ruptures, and rock falls. Since no surface fault-trace was reported, the determination of the causative blind fault remains an open issue for future investigation. Full article
(This article belongs to the Special Issue Modern Perspectives in Historical Seismology)
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27 pages, 5425 KiB  
Article
Effect of Orientation and Vegetation over the Embankment Crest for Energy Reduction at Downstream
Geosciences 2022, 12(10), 354; https://doi.org/10.3390/geosciences12100354 - 22 Sep 2022
Cited by 3 | Viewed by 1688
Abstract
Coastal embankments often collapse due to the tremendous destructive energy of an overtopping tsunami flow due to a deep scour by nappe flow. Hence, to clarify the nappe flow formation condition due to the overtopping, a series of tests were carried out within [...] Read more.
Coastal embankments often collapse due to the tremendous destructive energy of an overtopping tsunami flow due to a deep scour by nappe flow. Hence, to clarify the nappe flow formation condition due to the overtopping, a series of tests were carried out within a laboratory flume with immobile settings by lowering the downstream surface angle of an embankment model while keeping the upstream surface slope constant (1:1) with five non-dimensional overtopping depths and six different crest conditions. The conditions imposed on the embankment crest in the flow direction were without vegetation; horizontal crest, (−)4% descending crest slope, (+)4% ascending crest slope, and adding vegetation model with three different densities across the horizontal crest to improve resistance to the flow. The increased resistance provided by the vegetation models were categorized based on the spacing ratio between cylinders to diameter: sparse, intermediate, and dense. Increased vegetation density above the crest results in a significant reduction of flow energy by approximately 30–50% at the downstream brink edge and 40–60% at the downstream plunge basin. In contrast, the maximum energy reduction was found to be by the dense vegetation model. Additionally, owing to the steep slope of the water surface profile and the increasing vegetation density, the impinging jet’s impact point moved closer to the toe of an embankment. This implies that vegetation covers a smaller area while increasing density to mitigate the destructive intensity of flood/tsunami movement. Meanwhile, the descending crest scenario results in a faster nappe flow formation. In contrast, the ascending crest scenario delays the nappe formation while reducing the downstream slope angle. It maintains the sub-critical flow at the crest, except near the downstream brink edge. Full article
(This article belongs to the Special Issue Interdisciplinary Geosciences Perspectives of Tsunami Volume 4)
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20 pages, 5536 KiB  
Article
An Interactive WebGIS Integrating Environmental Susceptibility Mapping in a Self-Burning Waste Pile Using a Multi-Criteria Decision Analysis Approach
Geosciences 2022, 12(10), 352; https://doi.org/10.3390/geosciences12100352 - 21 Sep 2022
Cited by 6 | Viewed by 1924
Abstract
Mining activities promote resulting wastes, so coal mines are prone to release contaminants to the environment, namely to the soil and water. Therefore, the analysis of this type of risk is crucial in waste pile management. The São Pedro da Cova (Porto, Portugal) [...] Read more.
Mining activities promote resulting wastes, so coal mines are prone to release contaminants to the environment, namely to the soil and water. Therefore, the analysis of this type of risk is crucial in waste pile management. The São Pedro da Cova (Porto, Portugal) coal waste pile has been studied in recent years, with several data acquired from 2019–2021 under a research project using distinct methodologies. These results are now combined in a multi-approach method to estimate the environmental impacts of the waste pile and identify the contamination. With the integration of all the data in a Geographical Information System (GIS) environment, and to fulfill a scientific gap, this study aims: (i) to create a susceptibility map of contamination in the areas surrounding the self-burning coal waste pile in São Pedro da Cova, using Analytical Hierarchy Process (AHP) and Fuzzy AHP approaches; and (ii) to develop a webGIS application incorporating all the information acquired that can be useful for the residents of São Pedro da Cova and also to the decision-making public entities and researchers. The results obtained show that the contamination susceptibility is higher surrounding the abandoned mine, particularly along the waste piles and the corresponding runoff areas, which can be especially sensitive. Full article
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19 pages, 9375 KiB  
Article
Hazard and Risk-Based Tsunami Early Warning Algorithms for Ocean Bottom Sensor S-Net System in Tohoku, Japan, Using Sequential Multiple Linear Regression
Geosciences 2022, 12(9), 350; https://doi.org/10.3390/geosciences12090350 - 19 Sep 2022
Cited by 6 | Viewed by 1698
Abstract
This study presents robust algorithms for tsunami early warning using synthetic tsunami wave data at ocean bottom sensor (OBS) arrays with sequential multiple linear regression. The study focuses on the Tohoku region of Japan, where an S-net OBS system (150 pressure sensors) has [...] Read more.
This study presents robust algorithms for tsunami early warning using synthetic tsunami wave data at ocean bottom sensor (OBS) arrays with sequential multiple linear regression. The study focuses on the Tohoku region of Japan, where an S-net OBS system (150 pressure sensors) has been deployed. To calibrate the tsunami early warning system using realistic tsunami wave profiles at the S-net stations, 4000 stochastic tsunami simulations are employed. Forecasting models are built using multiple linear regression together with sequential feature selection based on Akaike Information Criterion and knee-point method to identify sensors that improve the accuracy most significantly. The study considers tsunami wave amplitude at a nearshore location and regional tsunami loss for buildings to develop hazard-based and risk-based tsunami warning algorithms. The models identify an optimal configuration of OBS stations and waiting time for issuing tsunami warnings. The model performance is compared against a base model, which only uses the earthquake magnitude and epicenter location. The result indicates that estimating the tsunami amplitude and loss via S-net improves accuracy. For the hazard-based forecasting, adding six sensors from the S-net improves the accuracy of the estimation most significantly with an optimal waiting time of 3 min. For the risk-based forecasting, a longer waiting time between 5 and 10 min is suitable. Full article
(This article belongs to the Special Issue Interdisciplinary Geosciences Perspectives of Tsunami Volume 4)
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35 pages, 6045 KiB  
Review
The Geoscience of In-Situ Combustion and High-Pressure Air Injection
Geosciences 2022, 12(9), 340; https://doi.org/10.3390/geosciences12090340 - 13 Sep 2022
Cited by 4 | Viewed by 2803
Abstract
Considering the global drive toward net-zero carbon emissions in the near future, the need to find clean sources of energy has never been more important. It is estimated that globally there are tens of thousands of depleted and abandoned oil fields that may [...] Read more.
Considering the global drive toward net-zero carbon emissions in the near future, the need to find clean sources of energy has never been more important. It is estimated that globally there are tens of thousands of depleted and abandoned oil fields that may be adapted to produce green energy. These may be re-cycled with the help of air injection, either from the production of hydrogen, as a direct result of oxidation of oil, or the exploitation of the inherent increase in heat flow and pressure via enhanced geothermal systems. In the past, the use of in-situ combustion (ISC) and high-pressure air injection (HPAI) have experienced many failures, largely due to poor project design and inappropriate reservoir selection. Here, we review data from field applications, experimental studies, and numerical modelling to define the roles of sub-surface sedimentology and petrophysics, structural geology, geomechanics, mineralogy, diagenesis, and petroleum geology on the success of ISC and HPAI. We show how current knowledge can help mitigate project failure via improved project design and initial reservoir selection. Improvements to the design and implementation of ISC and HPAI projects promise to allow the utilisation of the many abandoned oil fields, to produce green energy with the added benefit of the cost-effective, and materials and energy efficient, re-use of existing oil field infrastructure. We conclude that the integration of field data, laboratory experiments, and numerical modelling methods previously studied can be used to help develop ISC and minimize risk of failure. Full article
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10 pages, 3849 KiB  
Article
Augmented Reality in Seismic Risk Management: A Contribution to the Reduction of Non-Structural Damage
Geosciences 2022, 12(9), 332; https://doi.org/10.3390/geosciences12090332 - 03 Sep 2022
Cited by 3 | Viewed by 2243
Abstract
To increase seismic resilience is one of the challenges the developers of new technologies face to reduce seismic risk. We set up an augmented reality (AR) exhibition with which users’ curiosity was confronted with the opportunity to have a wealth of information on [...] Read more.
To increase seismic resilience is one of the challenges the developers of new technologies face to reduce seismic risk. We set up an augmented reality (AR) exhibition with which users’ curiosity was confronted with the opportunity to have a wealth of information on damaging earthquakes that could be a multimedia add-on to the plain “single-layer exhibit”. AR is an emergent technology developed to “augment” reality through various devices; it combines the real world with virtual items, such as images and videos. Our AR exhibition aims to: (i) show the effects of earthquakes even in cases of moderate magnitude; and (ii) promote preventive actions to reduce non-structural damage. It can be customized for different seismic scenarios. In addition, it offers a holistic approach to communicate problems and solutions—with the cost and degree of ease of execution for each solution—to reduce non-structural damage at home, school, and office. Our AR exhibition can do more than just a plain text or a preconceived video: it can trigger fruitful interaction between the presenters, or even the stand-alone poster, and the public. Such interactivity offers an easy engagement to people of all ages and cultural backgrounds. AR is, indeed, extremely flexible in raising recipients’ interest; moreover, it is an appealing tool for the digital native generations. The positive feedback received led us to conclude that this is an effective way to raise awareness and individual preparedness to seismic risk. Full article
(This article belongs to the Section Natural Hazards)
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20 pages, 3804 KiB  
Article
Investigation of the Factors Controlling the Duration and Productivity of Aftershocks Following Strong Earthquakes in Greece
Geosciences 2022, 12(9), 328; https://doi.org/10.3390/geosciences12090328 - 30 Aug 2022
Cited by 3 | Viewed by 1923
Abstract
Strong crustal earthquakes in Greece are typically followed by aftershocks, the properties of which are important factors in seismic hazard assessment. In order to examine the properties of earthquake sequences, we prepared an earthquake catalog comprising aftershock sequences with mainshocks of Mw [...] Read more.
Strong crustal earthquakes in Greece are typically followed by aftershocks, the properties of which are important factors in seismic hazard assessment. In order to examine the properties of earthquake sequences, we prepared an earthquake catalog comprising aftershock sequences with mainshocks of Mw ≥ 5.5 from 1995 to 2021. Regional aftershock parameters were estimated to highlight variations in aftershock decay and productivity among regions with similar seismotectonic characteristics. A statistically based method of estimating aftershock duration and a metric of relative aftershock productivity to examine the variations among the different cases were employed. From the detailed analysis of the selected seismic sequences, we attempt to unravel the physical mechanisms behind deviations in aftershock duration and productivity and resolve the relative contribution of background seismicity, the Omori–Utsu law parameters and the mainshock faulting properties. From our analysis, the duration of aftershock sequences depends upon the rupture process of the mainshock, independently of its magnitude. The same applies to aftershock productivity, however, other tectonic setting (e.g., seismic coupling) or source-related (e.g., focal depth, stress drop) parameters also contribute. The estimated regional parameters of the aftershock rate models could be utilized as initial ones to forecast the aftershock occurrence rates at the early stage following a mainshock. Full article
(This article belongs to the Special Issue Seismic Hazard Assessment and Earthquake Risk Mitigation)
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20 pages, 10372 KiB  
Article
Geomorphological and Morphometric Analyses of the Catanzaro Trough (Central Calabrian Arc, Southern Italy): Seismotectonic Implications
Geosciences 2022, 12(9), 324; https://doi.org/10.3390/geosciences12090324 - 29 Aug 2022
Cited by 7 | Viewed by 2196
Abstract
In this work, we investigated the landscape response to the recent activity of the faults affecting the Catanzaro Trough, a seismically active structural basin that developed transversally to the Calabrian Arc (Southern Italy) during the Neogene–Quaternary. We carried out a geomorphological and morphometric [...] Read more.
In this work, we investigated the landscape response to the recent activity of the faults affecting the Catanzaro Trough, a seismically active structural basin that developed transversally to the Calabrian Arc (Southern Italy) during the Neogene–Quaternary. We carried out a geomorphological and morphometric study of the drainage networks and basins intercepted by the Quaternary faults that were previously mapped through remote and field analyses. The study confirms the occurrence north of the Catanzaro Trough of a WNW–ESE-oriented left-lateral strike-slip fault system (here named the South Sila Piccola Fault System), which accommodates the differential SE-ward migration of the upper crustal sectors of the Calabrian Arc, and of a south-dipping WNW–ESE-oriented oblique fault system (the Lamezia-Catanzaro Fault System), characterized by a predominant normal component of movement. The latter delimits the Catanzaro Trough and accommodates the transition from a strike-slip regime to an extensional regime in the south. Inside the Catanzaro Trough, we detected for the first time a NNE–SSW-trending, WNW-dipping fault system (here named the Caraffa Fault System). This system contributes to accommodate the extension that occurs orthogonally to the southern sector of the Calabrian Arc. The geomorphological and morphometric analysis revealed the recent activity of these fault systems. In particular, the activity of the Caraffa Fault System is evidenced by the differential uplift and tilting of discrete areas inside the basin. Given its location, geometry, and kinematics, the Caraffa Fault System could be responsible for the occurrence of large historical earthquakes. Full article
(This article belongs to the Special Issue Tectonic Geomorphology in Modern Orogenic Zones)
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14 pages, 28381 KiB  
Article
Quantification of Alpine Metamorphism in the Edolo Diabase, Central Southern Alps
Geosciences 2022, 12(8), 312; https://doi.org/10.3390/geosciences12080312 - 21 Aug 2022
Cited by 2 | Viewed by 1622
Abstract
The Southern Alps are the retro-vergent belt of the European Alps that developed from Late Cretaceous subduction to Neogene times. The most prominent Alpine thrusts and folds, nowadays sealed off by the Adamello intrusion, were already developed before the continental collision and clasts [...] Read more.
The Southern Alps are the retro-vergent belt of the European Alps that developed from Late Cretaceous subduction to Neogene times. The most prominent Alpine thrusts and folds, nowadays sealed off by the Adamello intrusion, were already developed before the continental collision and clasts derived from the eroded pre-collisional wedge can be found in the Cretaceous foredeep sequences. In contrast, the thermal state attained by the Southern Alps during the long-lasting Alpine evolution is still unknown. This contribution provides evidence for Alpine metamorphism in the northern part of the central Southern Alps. Metamorphic conditions are determined for the alkaline Edolo diabase dykes that emplaced in the exhumed Variscan basement rocks before being deformed during the Alpine convergence (D3). The Alpine foliation in the Edolo diabase dykes is marked by actinolite, biotite, chlorite, epidote, albite, and titanite and it developed under greenschist facies conditions at temperature of 350–420 °C and pressure ≤0.2 GPa. The T/depth ratio indicates a minimum of 50–60 °C/km that is compatible with thermal gradients characteristic of arc settings. Based on radiometric ages from the literature, these conditions were attained during the Alpine subduction. Full article
(This article belongs to the Special Issue The Making of the Alps)
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24 pages, 10459 KiB  
Article
Maturity Matters in Provenance Analysis: Mineralogical Differences Explained by Sediment Transport from Fennoscandian and Variscan Sources
Geosciences 2022, 12(8), 308; https://doi.org/10.3390/geosciences12080308 - 18 Aug 2022
Cited by 3 | Viewed by 2123
Abstract
The significance of mineralogical maturity as a provenance indicator has long been debated and we use this study to demonstrate that it can indeed be a powerful tool to track the distribution of sandstone reservoirs. We investigate the cause of the pronounced geographic [...] Read more.
The significance of mineralogical maturity as a provenance indicator has long been debated and we use this study to demonstrate that it can indeed be a powerful tool to track the distribution of sandstone reservoirs. We investigate the cause of the pronounced geographic and stratigraphic differences in mineralogical composition that are found in the Upper Triassic–Lower Jurassic Gassum Formation across the Norwegian–Danish Basin and surrounding areas. Zircon U-Pb dating of 46 sandstone samples including analysis of 4816 detrital grains are combined with quantifications of the detrital mineralogical composition and placed in a sequence stratigraphic framework. The results show that the Gassum Formation can be divided into a southeastern region with high mineralogical maturity and a less mature region to the northwest with more feldspars, rock fragments, micas, and heavy minerals. Both the mineralogical assemblage and the provenance signature have been thoroughly homogenized in the SE region where sediment supplies from the Fennoscandian Shield and the Variscan Orogen are evident. In the NW region, sediment was initially supplied from Fennoscandia only, but the provenance abruptly changed from the Telemarkia Terrane to comprising also the more distant Caledonian Orogen resulting in a different mineralogical assemblage. The change occurred during a basinwide regression and may be caused by tectonic movements in the hinterland that permanently changed the composition of the sediment supplied to the basin. Full article
(This article belongs to the Collection Detrital Minerals: Their Application in Palaeo-Reconstruction)
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24 pages, 6514 KiB  
Article
Updated Understanding of the Ripley Landslide Kinematics Using Satellite InSAR
Geosciences 2022, 12(8), 298; https://doi.org/10.3390/geosciences12080298 - 30 Jul 2022
Cited by 9 | Viewed by 2653
Abstract
The Thompson River valley hosts 14 landslides along a 10 km section, which threaten the two major railroads connecting the Port of Vancouver and the interior provinces in Canada. The Ripley landslide is one of the active landslides in this section of the [...] Read more.
The Thompson River valley hosts 14 landslides along a 10 km section, which threaten the two major railroads connecting the Port of Vancouver and the interior provinces in Canada. The Ripley landslide is one of the active landslides in this section of the valley. Previous research at this site included an analysis of landslide deformations using satellite radar interferometry focusing on deformations measured in the line of sight between the satellite and the slopes, and average downslope displacement (deformations projected in the average downslope direction). Since then, further stratigraphic interpretation has provided an enhanced understanding of the Ripley landslide. In this update, the new stratigraphic interpretation is supplemented with satellite InSAR data from May 2015 to May 2017 to enhance the current understanding of the landslide kinematics. The results indicate that the Ripley landslide has been moving at a rate between 2 and 82 mm per year, corresponding to a very slow to slow landslide. It is also observed that the movements tend to be near-horizontal on areas closer to the toe of the landslide, while the vertical component of deformation increases near the scarp of the landslide. This, together with the interpreted stratigraphy, indicates the kinematics corresponds to a compound landslide. This is consistent with interpreted landslide kinematics of older, more mature landslides in the area that have shown episodes of retrogression and suggests the possibility of a similar future behaviour of the Ripley landslide. Full article
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64 pages, 23199 KiB  
Article
Upper Triassic Carbonate Records: Insights from the Most Complete Panthalassan Platform (Lime Peak, Yukon, Canada)
Geosciences 2022, 12(8), 292; https://doi.org/10.3390/geosciences12080292 - 28 Jul 2022
Cited by 2 | Viewed by 2403
Abstract
Upper Triassic carbonate platforms from the Panthalassa Ocean remain less-understood and less-studied than their Tethyan equivalents. This imbalance is largely due to the poorer preservation state of Panthalassan carbonate rock successions in terms of rock quality and depositional geometries, which prevents good appreciation [...] Read more.
Upper Triassic carbonate platforms from the Panthalassa Ocean remain less-understood and less-studied than their Tethyan equivalents. This imbalance is largely due to the poorer preservation state of Panthalassan carbonate rock successions in terms of rock quality and depositional geometries, which prevents good appreciation of depositional systems. In this context, carbonate exposures from Lime Peak (Yukon, Canada) represent an outstanding exception. There, the remains of an Upper Norian Panthalassan carbonate platform are well-exposed, show remarkably preserved depositional geometries and overall superior rock preservation. In this work, we analyse the carbonates from the Lime Peak area with particular attention to the vertical and lateral distribution of biotic assemblages and microfacies at the platform scale. Results demonstrate that the Lime Peak platform was surrounded by a basin with an aphotic sea bottom. The carbonate complex developed in warm waters characterized by high carbonate saturation. The area was also defined by moderate to high nutrient levels: this influenced the type of carbonate factory by favouring microbialites and sponges over corals. During its growth, Lime Peak was influenced by tectono-eustatism, which controlled the accommodation space at the platform top, primarily impacting the internal platform environments and the stability of the slope. Gaining better knowledge of the spatial distribution and dynamics of Upper Triassic organisms and sedimentary facies of Panthalassa in relation to tectono-eustatism lays the first foundations for reconstructing more robust platform models and understanding the evolution of other, more dismantled Upper Triassic Panthalassan carbonate systems through time. Full article
(This article belongs to the Special Issue Advances in Carbonate Sedimentology)
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20 pages, 7999 KiB  
Article
Mineralogy and Mineral Chemistry of the REE-Rich Black Sands in Beaches of the Kavala District, Northern Greece
Geosciences 2022, 12(7), 277; https://doi.org/10.3390/geosciences12070277 - 10 Jul 2022
Cited by 4 | Viewed by 2857
Abstract
The coastal area of the Kavala district, Northern Greece, is characterized by minerals enriched in rare earth elements (REE). The present study focuses on the mineralogy of the black sands from six different locations and the comprehensive mineral chemistry of the REE-bearing minerals, [...] Read more.
The coastal area of the Kavala district, Northern Greece, is characterized by minerals enriched in rare earth elements (REE). The present study focuses on the mineralogy of the black sands from six different locations and the comprehensive mineral chemistry of the REE-bearing minerals, allanite-(Ce), epidote, monazite, thorite, zircon and titanite. Allanite-(Ce) is the most important carrier of light REE (LREE) in the studied black sands, reaching up to 23.24 wt % ΣREE. The crystal chemistry of allanite-(Ce) transitions into ferriallanite-(Ce), due to the significant involvement of Fe3+. High resolution backscattered electron (BSE) images were used to identify zoning that corresponds to variations in REE, Th and U. These modifications follow the exchange scheme: (Ca + (Fe3+, Al))−1(LREE, Y, Th, U + (Fe2+, Mg, Mn))+1. Epidotes may also contain up to 0.5 REE3+ apfu. Monazite and thorite are found as inclusions in allanite-(Ce) and are enriched in Ce, La and Nd, together with Th and U. Some zircons are enriched in Hf, while some titanites host Nb and V. Full article
(This article belongs to the Section Geochemistry)
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43 pages, 3284 KiB  
Review
Order Parameter and Entropy of Seismicity in Natural Time before Major Earthquakes: Recent Results
Geosciences 2022, 12(6), 225; https://doi.org/10.3390/geosciences12060225 - 26 May 2022
Cited by 10 | Viewed by 1986
Abstract
A lot of work in geosciences has been completed during the last decade on the analysis in the new concept of time, termed natural time, introduced in 2001. The main advances are presented, including, among others, the following: First, the direct experimental verification [...] Read more.
A lot of work in geosciences has been completed during the last decade on the analysis in the new concept of time, termed natural time, introduced in 2001. The main advances are presented, including, among others, the following: First, the direct experimental verification of the interconnection between a Seismic Electric Signals (SES) activity and seismicity, i.e., the order parameter fluctuations of seismicity exhibit a clearly detectable minimum when an SES activity starts. These two phenomena are also linked closely in space. Second, the identification of the epicentral area and the occurrence time of an impending major earthquake (EQ) by means of the order parameter of seismicity and the entropy change of seismicity under time reversal as well as the extrema of their fluctuations. An indicative example is the M9 Tohoku EQ in Japan on 11 March 2011. Third, to answer the crucial question—when a magnitude 7 class EQ occurs—whether it is a foreshock or a mainshock. This can be answered by means of the key quantities already mentioned, i.e., the order parameter of seismicity and the entropy change of seismicity under time reversal along with their fluctuations. The explanation of the experimental findings identified before major EQs is given in a unified way on the basis of a physical model already proposed in the 1980s. Full article
(This article belongs to the Collection Advances in Statistical Seismology)
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27 pages, 10285 KiB  
Article
The Arkalochori Mw = 5.9 Earthquake of 27 September 2021 Inside the Heraklion Basin: A Shallow, Blind Rupture Event Highlighting the Orthogonal Extension of Central Crete
Geosciences 2022, 12(6), 220; https://doi.org/10.3390/geosciences12060220 - 24 May 2022
Cited by 9 | Viewed by 3380
Abstract
A strong, shallow earthquake occurred near Heraklion (Crete, Greece) on 27 September 2021. The earthquake produced significant ground deformation in the vicinity of Arkalochori village but without any evidence for surface ruptures of primary origin. We used geodetic (InSAR and GNSS) data to [...] Read more.
A strong, shallow earthquake occurred near Heraklion (Crete, Greece) on 27 September 2021. The earthquake produced significant ground deformation in the vicinity of Arkalochori village but without any evidence for surface ruptures of primary origin. We used geodetic (InSAR and GNSS) data to map motions of the Earth’s surface that occurred during and shortly after the earthquake. A 14 cm subsidence of the GNSS station ARKL and a maximum of 19 cm distance from the SAR satellite were recorded. The measured surface displacements were used to constrain the rupture geometry and slip distribution at depth. Our best-fitting inversion model suggests that the rupture occurred on a 13 km-long planar normal fault striking N195° E dipping 55° to the northwest, with major slip occurring to the east and updip of the hypocentre. The fault tip is located 1.2 km beneath the surface. The maximum coseismic slip occurred in the uppermost crust, in the depth interval of 4–6 km. A decrease in the fault offsets toward the Earth’s surface is likely caused by an increased frictional resistance of the shallow layers to rapid coseismic slip. Satellite observations made in the first month after the earthquake detected no post-seismic deformation (i.e., below one fringe or 2.8 cm). The seismic fault may be identified with the Avli (Lagouta) segment of the NNE-SSW striking, west-dipping, 23 km-long neotectonic Kastelli Fault Zone (KFZ). Part of the rupture occurred along the Kastelli segment, indicating a fault segment linkage and a history of overlapping ruptures along KFZ. Based on geological data and footwall topography we estimate an average slip rate between 0.17–0.26 mm/yr for the KFZ. The Arkalochori earthquake is a paradigm example for the on-going extension of Heraklion basin (central Crete) in the WNW-ESE direction, which is almost orthogonal to the E-W Messara graben and other active faults along the south coast of Crete. Full article
(This article belongs to the Special Issue Morphogenic Faulting: Current Practices and Future Challenges)
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17 pages, 315 KiB  
Article
Cascadia Subduction Zone Residents’ Tsunami Evacuation Expectations
Geosciences 2022, 12(5), 189; https://doi.org/10.3390/geosciences12050189 - 26 Apr 2022
Cited by 8 | Viewed by 2489
Abstract
The U.S. Pacific Northwest coast must be prepared to evacuate immediately after a Cascadia Subduction Zone earthquake. This requires coastal residents to understand the tsunami threat, have accurate expectations about warning sources, engage in preimpact evacuation preparedness actions, and plan (and practice) their [...] Read more.
The U.S. Pacific Northwest coast must be prepared to evacuate immediately after a Cascadia Subduction Zone earthquake. This requires coastal residents to understand the tsunami threat, have accurate expectations about warning sources, engage in preimpact evacuation preparedness actions, and plan (and practice) their evacuation logistics, including an appropriate transportation mode, evacuation route, and destination. A survey of 221 residents in three communities identified areas in which many coastal residents have reached adequate levels of preparedness. Moreover, residents who are not adequately prepared are willing to improve their performance in most of the areas in which they fall short. However, many respondents expect to engage in time-consuming evacuation preparations before evacuating. Additionally, their estimates of evacuation travel time might be inaccurate because only 28–52% had practiced their evacuation routes. These results indicate that more coastal residents should prepare grab-and-go kits to speed their departure, as well as practice evacuation preparation and evacuation travel to test the accuracy of these evacuation time estimates. Overall, these results, together with recommendations for overcoming them, can guide CSZ emergency managers in methods of improving hazard awareness and education programs. In addition, these data can guide transportation engineers’ evacuation analyses and evacuation plans. Full article
(This article belongs to the Special Issue Interdisciplinary Geosciences Perspectives of Tsunami Volume 4)
21 pages, 7138 KiB  
Article
Examining Rock Engineering Knowledge through a Philosophical Lens
Geosciences 2022, 12(4), 174; https://doi.org/10.3390/geosciences12040174 - 15 Apr 2022
Cited by 8 | Viewed by 2419
Abstract
This paper presents a philosophical examination of classical rock engineering problems as the basis to move from traditional knowledge to radical (innovative) knowledge. While this paper may appear abstract to engineers and geoscientists more accustomed to case studies and practical design methods, the [...] Read more.
This paper presents a philosophical examination of classical rock engineering problems as the basis to move from traditional knowledge to radical (innovative) knowledge. While this paper may appear abstract to engineers and geoscientists more accustomed to case studies and practical design methods, the aim is to demonstrate how the analysis of what constitutes engineering knowledge (what rock engineers know and how they know it) should always precede the integration of new technologies into empirical disciplines such as rock engineering. We propose a new conceptual model of engineering knowledge that combines experience (practical knowledge) and a priori knowledge (knowledge that is not based on experience). Our arguments are not a critique of actual engineering systems, but rather a critique of the (subjective) reasons that are invoked when using those systems, or to defend conclusions achieved using those systems. Our analysis identifies that rock engineering knowledge is shaped by cognitive biases, which over the years have created a sort of dogmatic barrier to innovation. It therefore becomes vital to initiate a discussion on the subject of engineering knowledge that can explain the challenges we face in rock engineering design at a time when digitalisation includes the introduction of machine algorithms that are supposed to learn from conditions of limited information. Full article
(This article belongs to the Section Geomechanics)
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23 pages, 2520 KiB  
Article
Geoheritage and Geosites: A Bibliometric Analysis and Literature Review
Geosciences 2022, 12(4), 169; https://doi.org/10.3390/geosciences12040169 - 13 Apr 2022
Cited by 40 | Viewed by 5042
Abstract
Geological heritage represents and brings together geological elements of great local and global relevance. It also promotes conservation and sustainable use. This study aims to perform a bibliometric analysis of the contributions that address the topics of geological heritage and geosites, using the [...] Read more.
Geological heritage represents and brings together geological elements of great local and global relevance. It also promotes conservation and sustainable use. This study aims to perform a bibliometric analysis of the contributions that address the topics of geological heritage and geosites, using the Scopus and Web of Science databases for the knowledge of trends and research focuses in this area. The methodology consists of: (i) the preparation of the idea and gathering information from a search on the subjects of interest (geoheritage and geosites); (ii) the merging of the databases and applying automated conversions; and (iii) the analysis of the results and the literature review. The first phase of the work identified 2409 and 1635 documents indexed in Scopus and WoS, respectively. The merged global database (2565 documents) identified the following words as analysis topics: geoconservation, geotourism, geopark, and geodiversity. The analysis also revealed the top five countries in scientific contributions as Italy (12.1%), Spain (8.77%), China (5.67%), Portugal (5.35%), and Brazil (5.31%). Finally, most of the publications focus on the characterisation, assessment, and development of geosite initiatives. The main lines of action and contributions to the topics (7.91%) highlight the fact that geoscientists worldwide value geosites for geoconservation and geotourism strategies. Full article
(This article belongs to the Special Issue Featured Papers in Geoheritage, Geoparks and Geotourism)
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28 pages, 10941 KiB  
Article
The Porosity in Heterogeneous Carbonate Reservoir Rocks: Tectonic versus Diagenetic Imprint—A Multi-Scale Study from the Hyblean Plateau (SE Sicily, Italy)
Geosciences 2022, 12(4), 149; https://doi.org/10.3390/geosciences12040149 - 25 Mar 2022
Cited by 9 | Viewed by 3459
Abstract
The petroleum industry has always been pursuing highly exploitable gas fields, which are often hosted in carbonate rocks. However, carbonates are highly heterogeneous and show different fabrics and structures as the result of sedimentation in various environments, and subsequent diagenesis and deformation. [...] Read more.
The petroleum industry has always been pursuing highly exploitable gas fields, which are often hosted in carbonate rocks. However, carbonates are highly heterogeneous and show different fabrics and structures as the result of sedimentation in various environments, and subsequent diagenesis and deformation. In this study, a multi-scale and multidisciplinary approach has been performed on classical reservoir rocks from the subsurface of the Hyblean Plateau (Sicily, Italy). We aim at unravelling the important and debated role of tectonic and diagenetic structures (mainly fractures as well as stylolites) in enhancing or reducing the porosity. Black shales, limestones, and laminites of intertidal environment represent the main lithologies. Structure cross-cutting relationships record different stages of the basin geological history, which are related to the tectonic evolution of the area. Our results show that porosity is uncommonly lightly affected by fractures and faults, because of their mineralization, whereas stylolites, which are often considered as barriers to fluid flow, show a certain porosity. Therefore, we want to highlight the importance of a multi-scale and multidisciplinary approach in the analysis of heterogeneously porous, fractured- and stylolite-rich carbonate rocks, and our study aspires to boost other similar gas reservoir studies in energy transition times. Full article
(This article belongs to the Special Issue Advances in Carbonate Sedimentology)
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36 pages, 8705 KiB  
Article
Console-Based Mapping of Mongolia Using GMT Cartographic Scripting Toolset for Processing TerraClimate Data
Geosciences 2022, 12(3), 140; https://doi.org/10.3390/geosciences12030140 - 21 Mar 2022
Cited by 19 | Viewed by 4169
Abstract
This paper explores spatial variability of the ten climatic variables of Mongolia in 2019: average minimal and maximal temperatures, wind speed, soil moisture, downward surface shortwave radiation (DSRAD), snow water equivalent (SWE), vapor pressure deficit (VPD), vapor pressure anomaly (VAP), monthly precipitation and [...] Read more.
This paper explores spatial variability of the ten climatic variables of Mongolia in 2019: average minimal and maximal temperatures, wind speed, soil moisture, downward surface shortwave radiation (DSRAD), snow water equivalent (SWE), vapor pressure deficit (VPD), vapor pressure anomaly (VAP), monthly precipitation and Palmer Drought Severity Index (PDSI). The PDSI demonstrates the simplified soil water balance estimating relative soil moisture conditions in Mongolia. The research presents mapping of the climate datasets derived from TerraClimate open source repository of the meteorological and climate measurements in NetCDF format. The methodology presented the compiled observations of Mongolia visualised by GMT coding approach using Generic Mapping Tools (GMT) cartographic scripting toolset. The results present 10 new maps of climate data over Mongolia made using automated cartographic techniques of GMT. Spatial environmental and climate analysis were conducted which determine relative distribution of PDSI and temperature extremes, precipitation and soil moisture, wind speed and DSRAD. The DSRAD showed minimum at 40 Wm2, maximum at 113 Wm2 in the Gobi Desert region, SWE (up to 491 mm), VAP and VPD compared with landmass parameters represent powerful cartographic tools to address complex regional climate and environmental issues in Mongolia, a country with contrasting topography, extreme climate conditions and unique environmental setting. Full article
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27 pages, 9290 KiB  
Article
SEM3D: A 3D High-Fidelity Numerical Earthquake Simulator for Broadband (0–10 Hz) Seismic Response Prediction at a Regional Scale
Geosciences 2022, 12(3), 112; https://doi.org/10.3390/geosciences12030112 - 02 Mar 2022
Cited by 10 | Viewed by 3881
Abstract
In this paper, we present SEM3D: a 3D high-fidelity numerical earthquake simulator that is tailored to predict the seismic wave field of complex earthquake scenarios from the fault to the epicenter site. SEM3D solves the wave-propagation problem by means of the spectral element [...] Read more.
In this paper, we present SEM3D: a 3D high-fidelity numerical earthquake simulator that is tailored to predict the seismic wave field of complex earthquake scenarios from the fault to the epicenter site. SEM3D solves the wave-propagation problem by means of the spectral element method (SEM). The presented demonstrative test case was a blind MW6.0 earthquake scenario at the European experimental site located in the sedimentary basin of Argostoli on the island of Kefalonia (Western Greece). A well-constrained geological model, obtained via geophysical inversion studies, and seismological model, given the large database of seismic traces recorded by the newly installed ARGONET network, of the site were considered. The domain of interest covered a region of 44 km × 44 km × 63 km, with the smallest grid size of 130 m × 130 m × 35 m. This allowed us to simulate the ground shaking in its entirety, from the seismic source to the epicenter site within a 0–10 Hz frequency band. Owing to the pseudo-spectral nature of the numerical method and given the high polynomial order (i.e., degree nine), the model featured 1.35·1010 DOFs (degrees of freedom). The variability of the synthetic wave field generated within the basin is assessed herein, exploring different random realizations of the mean velocity structure and heterogeneous rupture path. Full article
(This article belongs to the Special Issue Engineering Analysis of Near-Source Strong Ground Motion)
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24 pages, 6316 KiB  
Article
Morphosedimentary, Structural and Benthic Characterization of Carbonate Mound Fields on the Upper Continental Slope of the Northern Alboran Sea (Western Mediterranean)
Geosciences 2022, 12(3), 111; https://doi.org/10.3390/geosciences12030111 - 28 Feb 2022
Cited by 7 | Viewed by 2687
Abstract
Carbonate mounds clustering in three fields were characterized on the upper continental slope of the northern Alboran Sea by means of a detailed analysis of the morphosedimentary and structural features using high-resolution bathymetry and parametric profiles. The contemporary and past benthic and demersal [...] Read more.
Carbonate mounds clustering in three fields were characterized on the upper continental slope of the northern Alboran Sea by means of a detailed analysis of the morphosedimentary and structural features using high-resolution bathymetry and parametric profiles. The contemporary and past benthic and demersal species were studied using ROV underwater imagery and some samples. A total of 325 mounds, with heights between 1 and 18 m, and 204 buried mounds were detected between 155 to 401 m water depth. Transparent facies characterize the mounds, which root on at least six erosive surfaces, indicating different growth stages. At present, these mounds are covered with soft sediments and typical bathyal sedimentary habitat-forming species, such as sea-pens, cerianthids and sabellid polychaetes. Nevertheless, remains of colonial scleractinians, rhodoliths and bivalves were detected and their role as potential mound-forming species is discussed. We hypothesized that the formation of these mounds could be related to favorable climatic conditions for cold-water corals, possibly during the late Pleistocene. The occurrence on top of some mounds of abundant rhodoliths suggests that some mounds were in the photic zone during minimum sea level and boreal guest fauna (e.g., Modiolus modiolus), which declined in the western Mediterranean after the Termination 1a of the Last Glacial (Late Pleistocene). Full article
(This article belongs to the Section Geophysics)
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25 pages, 24976 KiB  
Article
Re-Evaluation of the Ionian Basin Evolution during the Late Cretaceous to Eocene (Aetoloakarnania Area, Western Greece)
Geosciences 2022, 12(3), 106; https://doi.org/10.3390/geosciences12030106 - 24 Feb 2022
Cited by 9 | Viewed by 2837
Abstract
Field investigation, Microfacies analysis, and biostratigraphy have been carried out in the central parts of the Ionian Basin (Aetoloakarnania area, Western Greece) in order to decipher the depositional environments that developed during the accumulation of the Upper Cretaceous to Eocene carbonate succession. Three [...] Read more.
Field investigation, Microfacies analysis, and biostratigraphy have been carried out in the central parts of the Ionian Basin (Aetoloakarnania area, Western Greece) in order to decipher the depositional environments that developed during the accumulation of the Upper Cretaceous to Eocene carbonate succession. Three different Standard Microfacies types (SMF) have been observed, corresponding to two different depositional environments (Facies Zones or FZ) of a platform progradation. The three SMF types which occur in the study area during the Upper Cretaceous to Eocene are: 1. SMF 3 that includes mudstone/wackestone with planktic foraminifera and radiolaria, corresponding to toe-of-slope (FZ: 3), 2. SMF 4, which can be classified as polymict clast-supported microbreccia, indicating a toe-of-slope-slope environment (FZ: 4) and 3. SMF 5 which is characterized by allochthonous bioclastic breccia and components deriving from adjacent platforms and which reflects a slope environment. Microfacies analysis provided evidence of a change in the origin of sedimentary components and biota showing the transition from toe-of-slope to slope, as well as a change in organism distribution. Full article
(This article belongs to the Special Issue Advances in Carbonate Sedimentology)
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28 pages, 7127 KiB  
Review
Geoheritage and Cultural Heritage—A Review of Recurrent and Interlinked Themes
Geosciences 2022, 12(2), 98; https://doi.org/10.3390/geosciences12020098 - 21 Feb 2022
Cited by 48 | Viewed by 5680
Abstract
Relationships between geoheritage and cultural heritage are being increasingly explored and have become one of the mainstreams within studies of geoheritage and geodiversity. In this review paper, we identify the main and secondary themes at the geoheritage—cultural heritage interface and provide examples of [...] Read more.
Relationships between geoheritage and cultural heritage are being increasingly explored and have become one of the mainstreams within studies of geoheritage and geodiversity. In this review paper, we identify the main and secondary themes at the geoheritage—cultural heritage interface and provide examples of specific topics and approaches. These themes include added cultural value to geoheritage sites, geoheritage in urban spaces, cultural landscapes, and the contribution of geoheritage to their identity, mining and quarrying heritage, linkages with natural disasters, history of science, and art. Intangible cultural heritage is also reviewed in the geoheritage context. In the closing part of the paper, various classifications of geoheritage—cultural heritage linkages are proposed, although it is concluded that themes and fields of inquiry are overlapping and interlinked, rendering one classification system not very feasible. Instead, a mind map to show these diverse connections is offered. The paper closes with recommendations for future studies, arising from this review and the identification of research gaps and under-researched areas. Full article
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14 pages, 5383 KiB  
Article
Ice Core Chronologies from the Antarctic Peninsula: The Palmer, Jurassic, and Rendezvous Age-Scales
Geosciences 2022, 12(2), 87; https://doi.org/10.3390/geosciences12020087 - 16 Feb 2022
Cited by 9 | Viewed by 3678
Abstract
In this study, we present the age scales for three Antarctic Peninsula (AP) ice cores: Palmer, Rendezvous, and Jurassic. The three cores are all intermediate-depth cores, in the 133–141 m depth range. Non-sea-salt sulfate ([nssSO42−]) and hydrogen peroxide (H2 [...] Read more.
In this study, we present the age scales for three Antarctic Peninsula (AP) ice cores: Palmer, Rendezvous, and Jurassic. The three cores are all intermediate-depth cores, in the 133–141 m depth range. Non-sea-salt sulfate ([nssSO42−]) and hydrogen peroxide (H2O2) display marked seasonal variability suitable for annual-layer counting. The Palmer ice core covers 390 years, 1621–2011 C.E., and is one of the oldest AP cores. Rendezvous and Jurassic are lower elevation high-snow accumulation sites and therefore cover shorter intervals, 1843–2011 C.E. and 1874–2011 C.E., respectively. The age scales show good agreement with known volcanic age horizons. The three chronologies’ start and end dates of volcanic events are compared to the volcanic events in the published WAIS Divide core. The age difference for the Palmer age scale is ±6 months, Rendezvous ±9 months, and Jurassic ±7 months. Our results demonstrate the advantage of dating several cores from the same region at the same time. Additional confidence can be gained in the age scales by evaluating and finding synchronicity of [nssSO42−] peaks amongst the sites. Full article
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21 pages, 3793 KiB  
Article
Comparative Analysis of Two Assessment Methods for the Geoeducational Values of Geosites: A Case Study from the Volcanic Island of Nisyros, SE Aegean Sea, Greece
Geosciences 2022, 12(2), 82; https://doi.org/10.3390/geosciences12020082 - 10 Feb 2022
Cited by 17 | Viewed by 2727
Abstract
In this study, the geoeducational value of five geosites, located in the aspiring geopark of the volcanic island of Nisyros, SE Aegean Sea, was assessed by means of two methods: the G-P method of Brilha (2016) and the M-GAM method. The first method [...] Read more.
In this study, the geoeducational value of five geosites, located in the aspiring geopark of the volcanic island of Nisyros, SE Aegean Sea, was assessed by means of two methods: the G-P method of Brilha (2016) and the M-GAM method. The first method takes into account 12 criteria belonging to the educational potential. The M-GAM method, on the other hand, takes into account the opinions of visitors who, as non-experts, express a different point of view that is rarely calculated or evaluated in different geosite assessment methods. For the better and more objective comparison of the two methods of evaluation of the educational potential of the study areas, the results were converted to a percentage scale (%). The first G-P method clearly highlights the high geological value of the studied geosites, which have a relatively high score and can be used for geotourism and geoeducation. The second method, on the other hand, yields a moderate score in areas with objectively high geological value. This is clearly evident, as this method considers the opinions of visitors who lack the necessary cognitive geological background, thereby underestimating the significance and potential of certain geological features due to lack of formal training. Full article
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22 pages, 55976 KiB  
Article
Digital Tools to Serve Geotourism and Sustainable Development at Psiloritis UNESCO Global Geopark in COVID Times and Beyond
Geosciences 2022, 12(2), 78; https://doi.org/10.3390/geosciences12020078 - 07 Feb 2022
Cited by 13 | Viewed by 3462
Abstract
Digital tools that aid geolocation, geointerpretation and geomodelling are increasingly used in the promotion of geoheritage and geoconservation. UNESCO Global Geoparks (UGGps) are complex regions that require a variety of approaches to advance geoconservation and public awareness, holistic heritage management and sustainable development. [...] Read more.
Digital tools that aid geolocation, geointerpretation and geomodelling are increasingly used in the promotion of geoheritage and geoconservation. UNESCO Global Geoparks (UGGps) are complex regions that require a variety of approaches to advance geoconservation and public awareness, holistic heritage management and sustainable development. UGGps need more diversified and applied digital tools to address these subjects. Additional efforts are made through their commitment to achieving sustainable development goals (SDGs) in the changing and challenging world of the COVID-19 pandemic and the exacerbation of climate change. In this study, we present three new digital applications developed for the Psiloritis UGGp in Southern Greece. These digital tools were developed under the implementation of the “Enhancement Plan” of the geopark via the RURITAGE, a project that supports rural regeneration through conservation, with a focus on local heritage. Digital tools developed in the project include an interactive digital map that demonstrates all properties of local heritage, products and services, two story maps focusing on historic churches and monasteries of the Amari district and on the natural and cultural values of Nida plateau, and a business-listing map with the affiliated geopark enterprises. These digital tools combine multiple applications and methods such as Wordpress webpages, web maps, spherical panoramas, multimedia, site interpretation, geolocation and virtual reality to aid the interpretation of natural and cultural heritage, promote important sites, demonstrate overlaps between nature and human society and support local productivity. Digital tools offer online access to interested parties in any area and are also used for in situ information sites. They are user-friendly, device-adjusted and available for sharing on social media and webpages. The applicability and effectiveness of these digital tools are proven to advance geotourism and the SDGs, in line with the provisions of the “World After roadmap” of UGGps. During the COVID-19 pandemic, the “visibility” of the Psiloritis UGGp was doubled via the use of these digital tools, as they have become popular among the general public. Full article
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29 pages, 80409 KiB  
Article
Reconstructing the Variscan Terranes in the Alpine Basement: Facts and Arguments for an Alpidic Orocline
Geosciences 2022, 12(2), 65; https://doi.org/10.3390/geosciences12020065 - 30 Jan 2022
Cited by 18 | Viewed by 5743
Abstract
The existence of pieces of the Variscan belt in the Alpine basement has been acknowledged for a long time but the correlation of these massifs to the litho-tectonic domains established in Western Europa outside the Alpine chain is still disputed. Due to their [...] Read more.
The existence of pieces of the Variscan belt in the Alpine basement has been acknowledged for a long time but the correlation of these massifs to the litho-tectonic domains established in Western Europa outside the Alpine chain is still disputed. Due to their ubiquitous character, the abundant late Variscan migmatites and granites are useless to reconstruct the Variscan architecture in the Alpine basement. Ophiolitic sutures, high- and low-grade metamorphic units, and foreland basins provide a preliminary reconstruction of the Variscan orogen exposed in the Alpine basement. The longitudinal extension of the Armorican and Saxo-Thuringian microcontinents between Laurussia and Gondwana is proposed independently of the Intra-alpine and Galatian terranes. The litho-tectonic units of the Corsica-Sardinia segment are correlated to the Moldanubian, Armorican and Saxo-Thuringian Domains. In the Alpine Helvetic and Penninic Domains, the Chamrousse ophiolites are ascribed to the Tepla-Le Conquet suture, whereas the Lepontine, and Stubach ophiolites represent the Rheic suture. The south-directed nappe stack of the South Alpine Domain is similar to the Moldanubian French Massif Central. In the Austroalpine nappe stack, the Ritting ophiolites separate Saxo-Thuringia and Armorica continental blocks. Disentangling the Variscan belt in the Alpine basement suggests a concave-to-the-East arcuate structure called here the Variscan Alpidic orocline. Full article
(This article belongs to the Special Issue Evolution of Modern and Ancient Orogenic Belts)
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27 pages, 3950 KiB  
Article
Quantitative Assessment of the Geosites of Chelmos-Vouraikos UNESCO Global Geopark (Greece)
Geosciences 2022, 12(2), 63; https://doi.org/10.3390/geosciences12020063 - 29 Jan 2022
Cited by 11 | Viewed by 3125
Abstract
The assessment of the geosites of Chelmos-Vouraikos UNESCO Global Geopark (UGGp) was carried out based on an established methodology for the evaluation of geoparks’ geosites. Such assessments should be used for sustainable development and geoconservation in geoparks. The selected methodology is based on [...] Read more.
The assessment of the geosites of Chelmos-Vouraikos UNESCO Global Geopark (UGGp) was carried out based on an established methodology for the evaluation of geoparks’ geosites. Such assessments should be used for sustainable development and geoconservation in geoparks. The selected methodology is based on a wider range of criteria concerning the overall value of each geosite, compared to other locations. Each criterion was scored and then three indices, Vedu, Vprot and Vedu were estimated for each geosite. The application of this methodology at Chelmos-Vouraikos UGGp has produced results which not only highlight the value of each geosite, but also provide ways for their utilization. The assessment of the 40 geosites of the geopark, identified geosites with high educational and touristic value (such as Portes–Triklia and the Cave of the Lakes), while geosites with increased protection-need value (the Tectonic Graben of Kalavryta) were also highlighted. Therefore, the assessment results will be used by the geopark to plan the effective management of the geosites based on their strengths and weaknesses, and which thus will promote the geopark and will contribute to the sustainable development of the local communities. The proposed methodology uses all possible criteria for its impartial application and despite a few minor problems that have been identified, it is considered appropriate for the assessment of geosites in Geoparks. The application of such evaluation methodologies is considered crucial for the development, protection and touristic promotion of geoparks. Full article
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31 pages, 16217 KiB  
Article
Assessment of Geological Heritage Sites and Their Significance for Geotouristic Exploitation: The Case of Lefkas, Meganisi, Kefalonia and Ithaki Islands, Ionian Sea, Greece
Geosciences 2022, 12(2), 55; https://doi.org/10.3390/geosciences12020055 - 24 Jan 2022
Cited by 11 | Viewed by 4610
Abstract
Geological heritage or geoheritage refers to the total of geosites, i.e., areas of high geological interest in a given area. Geosites have a high potential of attracting geotourists, thus contributing to the development of the local economy. Assessing sites of geological interest can [...] Read more.
Geological heritage or geoheritage refers to the total of geosites, i.e., areas of high geological interest in a given area. Geosites have a high potential of attracting geotourists, thus contributing to the development of the local economy. Assessing sites of geological interest can contribute to their promotion, as well as their preservation and protection. Greece’s geotectonic position in the convergent zone between the African and Eurasian plates has contributed to the existence of a considerable wealth of geosites, with the particularly active geotectonic region of the Ionian Sea characterized as a geoheritage hotspot. The purpose of this study is the selection of several such sites from the islands of Lefkas, Meganisi, Kefalonia and Ithaki and their assessment regarding their scientific, environmental, cultural, economic and aesthetic value. The most representative sites for the individual disciplines of geology (e.g., geomorphology, tectonics, stratigraphy and palaeontology) have been chosen, mapped and assessed, while indicative georoutes are proposed, which could aid the island’s geotouristic promotion to geologist and non-geologist future visitors. Full article
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27 pages, 8584 KiB  
Review
Mountain Permafrost Hydrology—A Practical Review Following Studies from the Andes
Geosciences 2022, 12(2), 48; https://doi.org/10.3390/geosciences12020048 - 19 Jan 2022
Cited by 17 | Viewed by 4792
Abstract
Climate change is expected to reduce water security in arid mountain regions around the world. Vulnerable water supplies in semi-arid zones, such as the Dry Andes, are projected to be further stressed through changes in air temperature, precipitation patterns, sublimation, and evapotranspiration. Together [...] Read more.
Climate change is expected to reduce water security in arid mountain regions around the world. Vulnerable water supplies in semi-arid zones, such as the Dry Andes, are projected to be further stressed through changes in air temperature, precipitation patterns, sublimation, and evapotranspiration. Together with glacier recession this will negatively impact water availability. While glacier hydrology has been the focus of scientific research for a long time, relatively little is known about the hydrology of mountain permafrost. In contrast to glaciers, where ice is at the surface and directly affected by atmospheric conditions, the behaviour of permafrost and ground ice is more complex, as other factors, such as variable surficial sediments, vegetation cover, or shallow groundwater flow, influence heat transfer and time scales over which changes occur. The effects of permafrost on water flow paths have been studied in lowland areas, with limited research in the mountains. An understanding of how permafrost degradation and associated melt of ground ice (where present) contribute to streamflow in mountain regions is still lacking. Mountain permafrost, particularly rock glaciers, is often conceptualized as a (frozen) water reservoir; however, rates of permafrost ground ice melt and the contribution to water budgets are rarely considered. Additionally, ground ice and permafrost are not directly visible at the surface; hence, uncertainties related to their three-dimensional extent are orders of magnitude higher than those for glaciers. Ground ice volume within permafrost must always be approximated, further complicating estimations of its response to climate change. This review summarizes current understanding of mountain permafrost hydrology, discusses challenges and limitations, and provides suggestions for areas of future research, using the Dry Andes as a basis. Full article
(This article belongs to the Special Issue Hydrological Systems and Models Applied in Permafrost)
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21 pages, 3494 KiB  
Review
Benthic Foraminifera as Environmental Indicators in Mediterranean Marine Caves: A Review
Geosciences 2022, 12(1), 42; https://doi.org/10.3390/geosciences12010042 - 16 Jan 2022
Cited by 11 | Viewed by 4252
Abstract
Marine caves are characterized by wide environmental variability for the interaction between marine and continental processes. Their conditions may be defined as extreme for inhabiting organisms due to the enclosed morphology, lack of light, and scarcity of nutrients. Therefore, it is necessary to [...] Read more.
Marine caves are characterized by wide environmental variability for the interaction between marine and continental processes. Their conditions may be defined as extreme for inhabiting organisms due to the enclosed morphology, lack of light, and scarcity of nutrients. Therefore, it is necessary to identify reliable ecological indicators for describing and assessing environmental conditions in these habitats even more than elsewhere. This review aims to provide the state of art related to the application of benthic foraminifera as proxies in the (paleo)ecological characterization of different habitats of marine caves. Special attention was addressed to a research project focused on Mediterranean marine caves with different characteristics, such as extent, morphology, freshwater influence, salinity, sediment type, oxygenation, and organic matter supply. This review aims to illustrate the reliability of foraminifera as an ecological and paleoecological indicator in these habitats. They respond to various environmental conditions with different assemblages corresponding to a very detailed habitat partitioning. Because marine caves may be considered natural laboratories for environmental variability, the results of these studies may be interpreted in the perspective of the global variability to understand the environmental drivers of future changes in marine systems. Full article
(This article belongs to the Special Issue Recent and Fossil Submarine Caves)
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23 pages, 851 KiB  
Review
A Survey of Uncertainty Quantification in Machine Learning for Space Weather Prediction
Geosciences 2022, 12(1), 27; https://doi.org/10.3390/geosciences12010027 - 07 Jan 2022
Cited by 16 | Viewed by 4818
Abstract
With the availability of data and computational technologies in the modern world, machine learning (ML) has emerged as a preferred methodology for data analysis and prediction. While ML holds great promise, the results from such models are not fully unreliable due to the [...] Read more.
With the availability of data and computational technologies in the modern world, machine learning (ML) has emerged as a preferred methodology for data analysis and prediction. While ML holds great promise, the results from such models are not fully unreliable due to the challenges introduced by uncertainty. An ML model generates an optimal solution based on its training data. However, if the uncertainty in the data and the model parameters are not considered, such optimal solutions have a high risk of failure in actual world deployment. This paper surveys the different approaches used in ML to quantify uncertainty. The paper also exhibits the implications of quantifying uncertainty when using ML by performing two case studies with space physics in focus. The first case study consists of the classification of auroral images in predefined labels. In the second case study, the horizontal component of the perturbed magnetic field measured at the Earth’s surface was predicted for the study of Geomagnetically Induced Currents (GICs) by training the model using time series data. In both cases, a Bayesian Neural Network (BNN) was trained to generate predictions, along with epistemic and aleatoric uncertainties. Finally, the pros and cons of both Gaussian Process Regression (GPR) models and Bayesian Deep Learning (DL) are weighed. The paper also provides recommendations for the models that need exploration, focusing on space weather prediction. Full article
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22 pages, 6694 KiB  
Article
How Academics and the Public Experienced Immersive Virtual Reality for Geo-Education
Geosciences 2022, 12(1), 9; https://doi.org/10.3390/geosciences12010009 - 24 Dec 2021
Cited by 17 | Viewed by 3754
Abstract
Immersive virtual reality can potentially open up interesting geological sites to students, academics and others who may not have had the opportunity to visit such sites previously. We study how users perceive the usefulness of an immersive virtual reality approach applied to Earth [...] Read more.
Immersive virtual reality can potentially open up interesting geological sites to students, academics and others who may not have had the opportunity to visit such sites previously. We study how users perceive the usefulness of an immersive virtual reality approach applied to Earth Sciences teaching and communication. During nine immersive virtual reality-based events held in 2018 and 2019 in various locations (Vienna in Austria, Milan and Catania in Italy, Santorini in Greece), a large number of visitors had the opportunity to navigate, in immersive mode, across geological landscapes reconstructed by cutting-edge, unmanned aerial system-based photogrammetry techniques. The reconstructed virtual geological environments are specifically chosen virtual geosites, from Santorini (Greece), the North Volcanic Zone (Iceland), and Mt. Etna (Italy). Following the user experiences, we collected 459 questionnaires, with a large spread in participant age and cultural background. We find that the majority of respondents would be willing to repeat the immersive virtual reality experience, and importantly, most of the students and Earth Science academics who took part in the navigation confirmed the usefulness of this approach for geo-education purposes. Full article
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