Geosciences

29 pages, 10302 KB

Open AccessEditor’s ChoiceReview

Late Quaternary Relative Sea-Level Changes and Vertical GNSS Motions in the Gulf of Corinth: The Asymmetric Localization of Deformation Inside an Active Half-Graben

by Niki Evelpidou, Athanassios Ganas, Anna Karkani, Evangelos Spyrou and Giannis Saitis

Geosciences 2023, 13(11), 329; https://doi.org/10.3390/geosciences13110329 - 28 Oct 2023

Cited by 7 | Viewed by 3292

Abstract

Remains of past sea levels such as tidal notches may provide valuable information for the investigation of relative sea-level changes (RSL) of eustatic/tectonic origin. In this review, we focus on case studies of coastal changes from the Corinth Gulf, where impacts of past [...] Read more.

Remains of past sea levels such as tidal notches may provide valuable information for the investigation of relative sea-level changes (RSL) of eustatic/tectonic origin. In this review, we focus on case studies of coastal changes from the Corinth Gulf, where impacts of past earthquakes can be traced through various indicators. The southern coast has undergone a tectonic uplift during the Holocene, whereas the northern coast has undergone subsidence. The magnitude of RSL fall in the south Corinth Gulf is larger than RSL rise in the north. Exploiting previous measurements and datings, we created a geodatabase regarding the relative sea-level changes of the whole gulf, including geodetic data based on permanent GNSS observations. The combination of geomorphological (long-term) and geodetic (short-term) data is a key advance for this area, which is characterized by fast rates of N-S crustal extension and strong earthquakes. The joint dataset fits the tectonic model of an active half-graben where the hanging wall (northern coast) subsides and the footwall (southern coast) is uplifted. The highest uplift rates (3.5 mm/year) are near Aigion, which indicates an asymmetric localization of deformation inside this active rift. Full article

(This article belongs to the Section Natural Hazards)

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22 pages, 11529 KB

Open AccessEditor’s ChoiceArticle

Influence of Root Reinforcement on Shallow Landslide Distribution: A Case Study in Garfagnana (Northern Tuscany, Italy)

by Lorenzo Marzini, Enrico D’Addario, Michele Pio Papasidero, Francesco Chianucci and Leonardo Disperati

Geosciences 2023, 13(11), 326; https://doi.org/10.3390/geosciences13110326 - 25 Oct 2023

Cited by 9 | Viewed by 3386

Abstract

In this work, we evaluated the influence of root structure on shallow landslide distribution. Root density measurements were acquired in the field and the corresponding root cohesion was estimated. Data were acquired from 150 hillslope deposit trenches dug in areas either devoid or [...] Read more.

In this work, we evaluated the influence of root structure on shallow landslide distribution. Root density measurements were acquired in the field and the corresponding root cohesion was estimated. Data were acquired from 150 hillslope deposit trenches dug in areas either devoid or affected by shallow landslides within the Garfagnana Valley (northern Tuscany, Italy). Results highlighted a correlation between the root reinforcement and the location of measurement sites. Namely, lower root density was detected within shallow landslides, with respect to neighboring areas. Root area ratio (RAR) data allowed us to estimate root cohesion by the application of the revised version of the Wu and Waldron Model. Then, we propose a new method for the assimilation of the lateral root reinforcement into the infinite slope model and the limit equilibrium approach by introducing the equivalent root cohesion parameter. The results fall within the range of root cohesion values adopted in most of the physically based shallow landslide susceptibility models known in the literature (mean values ranging between ca. 2 and 3 kPa). Moreover, the results are in line with the scientific literature that has demonstrated the link between root mechanical properties, spatial variability of root reinforcement, and shallow landslide locations. Full article

(This article belongs to the Section Natural Hazards)

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17 pages, 11530 KB

Open AccessEditor’s ChoiceArticle

Ionospheric Total Electron Content (TEC) Anomalies as Earthquake Precursors: Unveiling the Geophysical Connection Leading to the 2023 Moroccan 6.8 Mw Earthquake

by Karan Nayak, Charbeth López-Urías, Rosendo Romero-Andrade, Gopal Sharma, German Michel Guzmán-Acevedo and Manuel Edwiges Trejo-Soto

Geosciences 2023, 13(11), 319; https://doi.org/10.3390/geosciences13110319 - 24 Oct 2023

Cited by 38 | Viewed by 6235

Abstract

The study delves into the relationship between ionospheric total electron content (TEC) anomalies and seismic activity, with a focus on Morocco’s 6.8 Mw earthquake on 8 September 2023, lying within a tectonically active region at the convergence of the African and Eurasian Plates. [...] Read more.

The study delves into the relationship between ionospheric total electron content (TEC) anomalies and seismic activity, with a focus on Morocco’s 6.8 Mw earthquake on 8 September 2023, lying within a tectonically active region at the convergence of the African and Eurasian Plates. To enhance the reliability of our findings, we incorporate space weather conditions, utilizing indices (Dst, Kp, and F10.7) to pinpoint periods of stable space weather. This minimizes the possibility of erroneously attributing natural ionospheric fluctuations to seismic events. Notably, our TEC analysis unveils positive and negative anomalies, with some occurring up to a week before the earthquake. These anomalies, exceeding predefined thresholds, provide compelling evidence of significant deviations from typical ionospheric conditions. Spatial mapping techniques employing both station-specific vTEC data and pseudorandom noise codes (PRNs) from multiple global navigation satellite system (GNSS) stations highlight a strong correlation between ionospheric anomalies and the earthquake’s epicenter. The integration of PRNs enhances coverage and sensitivity to subtle anomalies. Additionally, the analysis of satellite imagery and ground displacement data using Sentinel-1 confirms significant ground uplift of approximately 15 cm following the earthquake, shedding light on surface responses to seismic events. These findings underscore the potential of ionospheric science in advancing earthquake early warning systems and deepening our understanding of earthquake precursors, thus contributing to the mitigation of seismic event impacts and the protection of lives and infrastructure. Full article

(This article belongs to the Special Issue Precursory Phenomena Prior to Earthquakes 2023)

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17 pages, 7572 KB

Open AccessEditor’s ChoiceArticle

Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions

by Ritu Ghose, Patricia Persaud and Robert W. Clayton

Geosciences 2023, 13(11), 320; https://doi.org/10.3390/geosciences13110320 - 24 Oct 2023

Cited by 14 | Viewed by 2946

Abstract

We constrained sedimentary basin structure using a nodal seismic array consisting of ten dense lines that overlie multiple basins in the northern Los Angeles area. The dense array consists of 758 seismic nodes, spaced ~250–300 m apart along linear transects, that recorded ground [...] Read more.

We constrained sedimentary basin structure using a nodal seismic array consisting of ten dense lines that overlie multiple basins in the northern Los Angeles area. The dense array consists of 758 seismic nodes, spaced ~250–300 m apart along linear transects, that recorded ground motions for 30–35 days. We applied the receiver function (RF) technique to 16 teleseismic events to investigate basin structure. Primary basin-converted phases were identified in the RFs. A shear wave velocity model produced in a separate study using the same dataset was incorporated to convert the basin time arrivals to depth. The deepest part of the San Bernardino basin was identified near the Loma Linda fault at a depth of 2.4 km. Basin depths identified at pierce points for separate events reveal lateral changes in basin depth across distances of ~2–3 km near individual stations. A significant change in basin depth was identified within a small distance of ~4 km near the San Jacinto fault. The San Gabriel basin exhibited the largest basin depths of all three basins, with a maximum depth of 4.2 km. The high lateral resolution from the dense array helped to reveal more continuous structures and reduce uncertainties in the RFs interpretation. We discovered a more complex basin structure than previously identified. Our findings show that the basins’ core areas are not the deepest, and significant changes in basin depth were observed near some faults, including the San Jacinto fault, Fontana fault, Red Hill fault and Indian Hill fault. Full article

(This article belongs to the Special Issue Advances in Seismic Hazard Assessment)

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14 pages, 7301 KB

Open AccessEditor’s ChoiceArticle

Geomorphological Evolution of Volcanic Cliffs in Coastal Areas: The Case of Maronti Bay (Ischia Island)

by Luigi Massaro, Giovanni Forte, Melania De Falco and Antonio Santo

Geosciences 2023, 13(10), 313; https://doi.org/10.3390/geosciences13100313 - 17 Oct 2023

Cited by 3 | Viewed by 2930

Abstract

The morphoevolution of coastal areas is due to the interactions of multiple continental and marine processes that define a highly dynamic environment. These processes can occur as rapid catastrophic events (e.g., landslides, storms, and coastal land use) or as slower continuous processes (i.e., [...] Read more.

The morphoevolution of coastal areas is due to the interactions of multiple continental and marine processes that define a highly dynamic environment. These processes can occur as rapid catastrophic events (e.g., landslides, storms, and coastal land use) or as slower continuous processes (i.e., wave, tidal, and current actions), creating a multi-hazard scenario. Maronti Bay (Ischia Island, Southern Italy) can be classified as a pocket beach that represents an important tourist and environmental area for the island, although it has been historically affected by slope instability, sea cliff recession, and coastal erosion. In this study, the historical morphoevolution of the shoreline was analysed by means of a dataset of aerial photographs and cartographic information available in the literature over a 25-year period. Furthermore, the role of cliff recession and its impact on the beach was also explored, as in recent years, the stability condition of the area was worsened by the occurrence of a remarkable landslide in 2019. The latter was reactivated following a cloudburst on the 26th of November 2022 that affected the whole Island and was analysed with the Dem of Difference technique. It provided an estimate of the mobilised volumes and showed how the erosion and deposition areas were distributed and modified by wave action. The insights from this research can be valuable in developing mitigation strategies and protective measures to safeguard the surrounding environment and ensure the safety of residents and tourists in this multi-hazard environment. Full article

(This article belongs to the Special Issue Remote Sensing Monitoring of Geomorphological Hazards)

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19 pages, 4310 KB

Open AccessEditor’s ChoiceArticle

An Experimental Investigation on Dike Stabilization against Floods

by Sohail Iqbal and Norio Tanaka

Geosciences 2023, 13(10), 307; https://doi.org/10.3390/geosciences13100307 - 13 Oct 2023

Cited by 8 | Viewed by 3854

Abstract

A flood protection dike blends seamlessly with natural surroundings. These dikes stand as vital shields, mitigating the catastrophic effects of floods and preserving both communities and ecosystems. Their design not only aids in controlling water flow but also ensures minimal disruption to the [...] Read more.

A flood protection dike blends seamlessly with natural surroundings. These dikes stand as vital shields, mitigating the catastrophic effects of floods and preserving both communities and ecosystems. Their design not only aids in controlling water flow but also ensures minimal disruption to the local environment and its biodiversity. The present study used a uniform cohesionless sand with d₅₀ = 0.9 mm to investigate the local scour process near a single combined dike (permeable and impermeable), replicating a flooding scenario. The experiments revealed that the maximum scour depth is likely to occur at the upstream edge of the dike, resembling a local scour observed around a scaled-down emerged dike in an open channel. The scour hole downstream of the dike gets shallower as it gets smaller, as do the horseshoe vortices that surround it. Additionally, by combining different pile shapes, the flow surrounding the dike was changed to reduce horseshoe vortices, resulting in scour length and depth reductions of 48% at the nose and 45% and 65% at the upstream and downstream dike–wall junction, respectively. Contrarily, the deposition height downstream of the dike had a reciprocal effect on permeability, which can severely harm the riverbank defense system. The combined dike demonstrates their ability to mitigate scour by reducing the flow swirls formed around the dike. The suggested solutions can slow down the rapid deterioration and shield the dike and other river training infrastructure from scour-caused failures. Full article

(This article belongs to the Section Natural Hazards)

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33 pages, 13952 KB

Open AccessEditor’s ChoiceArticle

Earthquake Environmental Effects and Building Properties Controlling Damage Caused by the 6 February 2023 Earthquakes in East Anatolia

by Spyridon Mavroulis, Ioannis Argyropoulos, Emmanuel Vassilakis, Panayotis Carydis and Efthymis Lekkas

Geosciences 2023, 13(10), 303; https://doi.org/10.3390/geosciences13100303 - 9 Oct 2023

Cited by 14 | Viewed by 7389

Abstract

On 6 February 2023, East Anatolia was devastated by two major earthquakes resulting in hundreds of thousands of collapses and tens of thousands of human casualties. This paper investigates the factors related to building properties and earthquake environmental effects (EEEs) that contributed to [...] Read more.

On 6 February 2023, East Anatolia was devastated by two major earthquakes resulting in hundreds of thousands of collapses and tens of thousands of human casualties. This paper investigates the factors related to building properties and earthquake environmental effects (EEEs) that contributed to the building damage grade and distribution in southeastern Turkey. In regards to the building construction properties, the loose enforcement of the building code, the random urban planning solutions and the poor construction standards are the main construction deficiencies that led to one of the largest disasters in Turkey’s recent history. Regarding geological factors, the triggering of primary and secondary EEEs largely shaped the grade and distribution of damage. Where coseismic surface ruptures intersected with the built environment, heavy to very heavy structural damage was observed. This was evident in many cases along the ruptured segments of the East Anatolian Fault Zone (EAFZ). Liquefaction observed close to waterbodies caused damage typical of building foundation load-bearing capacity loss. The earthquake-triggered landslides affected mainly mountainous and semi-mountainous settlements characterized with pre-earthquake high related susceptibility. The high susceptibility to generation of EEEs was extensively confirmed in many cases resulting in extensive damage. The provided information highlights the importance of such studies for hazard mitigation and disaster risk reduction. Full article

(This article belongs to the Special Issue Active Tectonics and Earthquakes)

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27 pages, 10621 KB

Open AccessFeature PaperEditor’s ChoiceArticle

Geomorphology, Geoarchaeology, and Geochronology of the Upper Pleistocene Archaeological Site of El Olivo Cave (Llanera, Asturias, Northern Spain)

by Jesús F. Jordá Pardo, David Álvarez-Alonso, María de Andrés-Herrero, Daniel Ballesteros, Pilar Carral, Aitor Hevia-Carrillo, Jorge Sanjurjo, Santiago Giralt and Montserrat Jiménez-Sánchez

Geosciences 2023, 13(10), 301; https://doi.org/10.3390/geosciences13100301 - 7 Oct 2023

Cited by 2 | Viewed by 4013

Abstract

El Olivo Cave (Pruvia de Arriba, Llanera, Asturias, Spain) is a small karst cave located in the Aboño River basin and formed in the Cretaceous limestone of the Mesozoic cover of the Cantabrian Mountains (north of the Iberian Peninsula). It contains an important [...] Read more.

El Olivo Cave (Pruvia de Arriba, Llanera, Asturias, Spain) is a small karst cave located in the Aboño River basin and formed in the Cretaceous limestone of the Mesozoic cover of the Cantabrian Mountains (north of the Iberian Peninsula). It contains an important upper Pleistocene sedimentary, archaeological, and paleontological record, with abundant technological evidence and faunal remains. The archaeological record shows a first occupation that could correspond to the Middle Paleolithic and a second occupation in the Middle Magdalenian. The stratigraphic sequence inside and outside the cave was studied with geoarchaeological methodology. In this paper, the lithostratigraphic sequence is analyzed, and the data from the granulometric, mineralogical, edaphological, and radiometric analyses are presented. The results of these analyses enable an accurate interpretation of both the lithostratigraphy of the deposit and the processes responsible for its formation and subsequent evolution. The available numerical dates allow us to locate the first sedimentation episode in the cave in OIS 7a, in the Middle Pleistocene, the base of the outer fluvial sedimentation in the cold OIS 3a stage of the Upper Pleistocene and the Magdalenian occupation in the Last Glacial Maximum (OIS 2) at the end of the Late Pleistocene. Full article

(This article belongs to the Special Issue Pleistocene Hunter-Gatherers Geoarchaeology)

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35 pages, 20304 KB

Open AccessEditor’s ChoiceReview

Metamorphic Remnants of the Variscan Orogeny across the Alps and Their Tectonic Significance

by Manuel Roda, Maria Iole Spalla, Marco Filippi, Jean-Marc Lardeaux, Gisella Rebay, Alessandro Regorda, Davide Zanoni, Michele Zucali and Guido Gosso

Geosciences 2023, 13(10), 300; https://doi.org/10.3390/geosciences13100300 - 6 Oct 2023

Cited by 7 | Viewed by 3511

Abstract

Lithospheric slices preserving pre-Alpine metamorphic imprints are widely described in the Alps. The Variscan parageneses recorded in continental, oceanic, and mantle rocks suggest a heterogeneous metamorphic evolution across the Alpine domains. In this contribution, we collect quantitative metamorphic imprints and ages of samples [...] Read more.

Lithospheric slices preserving pre-Alpine metamorphic imprints are widely described in the Alps. The Variscan parageneses recorded in continental, oceanic, and mantle rocks suggest a heterogeneous metamorphic evolution across the Alpine domains. In this contribution, we collect quantitative metamorphic imprints and ages of samples that document Variscan tectonometamorphic evolution from 420 to 290 Ma. Based on age distribution and metamorphic imprint, three main stages can be identified for the Variscan evolution of the Alpine region: Devonian (early Variscan), late Devonian–late Carboniferous (middle Variscan), and late Carboniferous–early Permian (late Variscan). The dominant metamorphic imprint during Devonian times was recorded under eclogite and HP granulite facies conditions in the Helvetic–Dauphinois–Provençal, Penninic, and eastern Austroalpine domains and under Ep-amphibolite facies conditions in the Southalpine domain. These metamorphic conditions correspond to a mean Franciscan-type metamorphic field gradient. During the late Devonian–late Carboniferous period, in the Helvetic–Dauphinois–Provençal and central Austroalpine domains, the dominant metamorphic imprint developed under eclogite and HP granulite facies conditions with a Franciscan field gradient. Amphibolite facies conditions dominated in the Penninic and Southalpine domains and corresponded to a Barrovian-type metamorphic field gradient. At the Carboniferous–Permian transition, the metamorphic imprints mainly developed under amphibolite-LP granulite facies conditions in all domains of the Alps, corresponding to a mean metamorphic field gradient at the transition between Barrovian and Abukuma (Buchan) types. This distribution of the metamorphic imprints suggests a pre-Alpine burial of oceanic and continental crust underneath a continental upper plate, in a scenario of single or multiple oceanic subductions preceding the continental collision. Both scenarios are discussed and revised considering the consistency of collected data and a comparison with numerical models. Finally, the distribution of Devonian to Triassic geothermal gradients agrees with a sequence of events that starts with subduction, continues with continental collision, and ends with the continental thinning announcing the Jurassic oceanization. Full article

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

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24 pages, 13722 KB

Open AccessEditor’s ChoiceArticle

Prediction of Water Quality in Reservoirs: A Comparative Assessment of Machine Learning and Deep Learning Approaches in the Case of Toowoomba, Queensland, Australia

by Syeda Zehan Farzana, Dev Raj Paudyal, Sreeni Chadalavada and Md Jahangir Alam

Geosciences 2023, 13(10), 293; https://doi.org/10.3390/geosciences13100293 - 27 Sep 2023

Cited by 14 | Viewed by 3895

Abstract

The effective management of surface water bodies, such as rivers, lakes, and reservoirs, necessitates a comprehensive understanding of water quality status. Altered precipitation patterns due to climate change may significantly affect the water quality and influence treatment procedures. This study aims to identify [...] Read more.

The effective management of surface water bodies, such as rivers, lakes, and reservoirs, necessitates a comprehensive understanding of water quality status. Altered precipitation patterns due to climate change may significantly affect the water quality and influence treatment procedures. This study aims to identify the most suitable water quality prediction models for the assessment of the water quality status for three water supply reservoirs in Toowoomba, Australia. It employed four machine learning and two deep learning models for determining the Water Quality Index (WQI) based on five parameters sensitive to rainfall impact. Temporal WQI variations over a period of 22 years (2000–2022) are scrutinised across 4 seasons and 12 months. Through regression analysis, both machine learning and deep learning models anticipate WQI gauged by seven accuracy metrics. Notably, XGBoost and GRU yielded exceptional outcomes, showcasing an R² value of 0.99. Conversely, Bidirectional LSTM (BiLSTM) demonstrated moderate accuracy with results hovering at 88% to 90% for water quality prediction across all reservoirs. The Coefficient of Efficiency (CE) and Willmott Index (d) showed that the models capture patterns well, while MAE, MAPE and RMSE provided good performance metrics for the RFR, XGBoost and GRU models. These models have provided valuable knowledge that can be utilised to assess the adverse consequences of extreme climate events such as shifts in rainfall patterns. These insights can be used to improve strategies for managing water bodies more effectively. Full article

(This article belongs to the Topic Hydro-Meteorological Hazards: Forecasting, Assessment and Risk Management)

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35 pages, 87769 KB

Open AccessEditor’s ChoiceArticle

Mass-Movement Causes and Landslide Susceptibility in River Valleys of Lowland Areas: A Case Study in the Central Radunia Valley, Northern Poland

by Anna Małka, Lesław Zabuski, Frieder Enzmann and Arkadiusz Krawiec

Geosciences 2023, 13(9), 277; https://doi.org/10.3390/geosciences13090277 - 13 Sep 2023

Cited by 1 | Viewed by 5638

Abstract

This work aims to analyse the mechanisms and factors contributing to shallow soil landslides in river valleys entrenched in lowlands on the example of the Central Radunia Valley. The combination of susceptibility analysis using geographic-information-system-based statistical models, field surveys, analysis of archival materials, [...] Read more.

This work aims to analyse the mechanisms and factors contributing to shallow soil landslides in river valleys entrenched in lowlands on the example of the Central Radunia Valley. The combination of susceptibility analysis using geographic-information-system-based statistical models, field surveys, analysis of archival materials, and numerical modelling for the analysis of slope stability and hydrogeological processes allows for comprehensive landslide reconstruction, mass movement mechanism description, and an explanation of the role of triggering and causal factors. The results emphasise the need for cross-disciplinary studies of shallow soil landslides. The identification and prioritisation of the causal factors indicate that geomorphological conditions play a particularly important role. The current study shows that the greatest influence on landslide formation in the Central Radunia Valley is slope angle, as determined using a high-resolution digital elevation model. The slope angle factor is sufficient to produce a reliable susceptibility map (the areas under the curve of the success rate and prediction rate curves are 87.84% and 85.34%, respectively). However, numerical modelling of slope failure also clearly indicated that there was a significant influence of anthropogenic impacts on the landslide process. We determined that the main triggering factor causing the January 2019 Rutki landslide was related to the drilling of a borehole on 10 January 2019. The water used for drilling hydrated the soil and thus weakened the stability conditions. Full article

(This article belongs to the Topic Landslide Prediction, Monitoring and Early Warning)

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18 pages, 4876 KB

Open AccessEditor’s ChoiceArticle

Flood-Prone Zones of Meandering Rivers: Machine Learning Approach and Considering the Role of Morphology (Kashkan River, Western Iran)

by Kaveh Ghahraman, Balázs Nagy and Fatemeh Nooshin Nokhandan

Geosciences 2023, 13(9), 267; https://doi.org/10.3390/geosciences13090267 - 3 Sep 2023

Cited by 8 | Viewed by 3433

Abstract

We utilized the random forest (RF) machine learning algorithm, along with nine topographical/morphological factors, namely aspect, slope, geomorphons, plan curvature, profile curvature, terrain roughness index, surface texture, topographic wetness index (TWI), and elevation. Our objective was to identify flood-prone areas along the meandering [...] Read more.

We utilized the random forest (RF) machine learning algorithm, along with nine topographical/morphological factors, namely aspect, slope, geomorphons, plan curvature, profile curvature, terrain roughness index, surface texture, topographic wetness index (TWI), and elevation. Our objective was to identify flood-prone areas along the meandering Kashkan River and investigate the role of topography in riverbank inundation. To validate the flood susceptibility map generated by the random forest algorithm, we employed Sentinel-1 GRDH SAR imagery from the March 2019 flooding event in the Kashkan river. The SNAP software and the OTSU thresholding method were utilized to extract the flooded/inundated areas from the SAR imagery. The results showed that the random forest model accurately pinpointed areas with a “very high” and “high” risk of flooding. Through analysis of the cross-sections and SAR-based flood maps, we discovered that the topographical confinement of the meander played a crucial role in the extent of inundation along the meandering path. Moreover, the findings indicated that the inner banks along the Kashkan river were more prone to flooding compared to the outer banks. Full article

(This article belongs to the Special Issue Natural Hazards in Central and Eastern Europe: The Role of Climate Change)

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19 pages, 10961 KB

Open AccessEditor’s ChoiceArticle

Paleogeographic and Tectonic Evolution of the Earliest Wedge-Top Basin in the Southern Apennines: New Insights from the Paleocurrent Analysis of the Cilento Group Deposits (Southern Italy)

by Mubashir Mehmood, Sabatino Ciarcia, Luca Lo Schiavo, Jacopo Natale and Stefano Vitale

Geosciences 2023, 13(8), 238; https://doi.org/10.3390/geosciences13080238 - 8 Aug 2023

Cited by 5 | Viewed by 3042

Abstract

Our research focuses on the reconstruction of turbidity paleocurrents of the Cilento Group in the Cilento area (southern Apennines, Italy). These deposits were formed in the wedge-top basin above the oceanic Ligurian Accretionary Complex, the early orogenic wedge of the southern Apennines. The [...] Read more.

Our research focuses on the reconstruction of turbidity paleocurrents of the Cilento Group in the Cilento area (southern Apennines, Italy). These deposits were formed in the wedge-top basin above the oceanic Ligurian Accretionary Complex, the early orogenic wedge of the southern Apennines. The Cilento Group succession, whose age ranges between the uppermost Burdigalian and lowermost Tortonian, consists of a thick pile of sandstones, conglomerates, marls and pelites grouped in two formations (Pollica and San Mauro Fms). We retrieved information on the turbidity current directions through sedimentary features such as flute and groove casts, flame structures and ripple marks. The aim of this study is to shed light on the early tectonic evolution of the southern Apennines by reconstructing the geometry of this basin, the source areas that fed it and the paleogeography of the central Mediterranean area in the Miocene. We analyzed 74 sites in both formations and collected 338 measurements of paleocurrent indicators. Because the succession was affected by severe thrusting and folding, every paleocurrent measurement was restored, reinstating the bedding in the horizontal attitude. Results indicate a complex pattern of turbidity current flow directions consistent with a basin model fed by a spectrum of sources, including recycled clasts from the Ligurian Accretionary Complex, Calabria–Peloritani Terrane and the Apennine Platform units and volcaniclastics from the synorogenic volcanoes located in the Sardinia block. Full article

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

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17 pages, 12700 KB

Open AccessEditor’s ChoiceArticle

In Situ Cosmogenic ¹⁰Be Dating of Laurentide Ice Sheet Retreat from Central New England, USA

by Jason S. Drebber, Christopher T. Halsted, Lee B. Corbett, Paul R. Bierman and Marc W. Caffee

Geosciences 2023, 13(7), 213; https://doi.org/10.3390/geosciences13070213 - 15 Jul 2023

Cited by 3 | Viewed by 3360

Abstract

Constraining the timing and rate of Laurentide Ice Sheet (LIS) retreat through the northeastern United States is important for understanding the co-evolution of complex climatic and glaciologic events that characterized the end of the Pleistocene epoch. However, no in situ cosmogenic ¹⁰Be [...] Read more.

Constraining the timing and rate of Laurentide Ice Sheet (LIS) retreat through the northeastern United States is important for understanding the co-evolution of complex climatic and glaciologic events that characterized the end of the Pleistocene epoch. However, no in situ cosmogenic ¹⁰Be exposure age estimates for LIS retreat exist through large parts of Connecticut or Massachusetts. Due to the large disagreement between radiocarbon and ¹⁰Be ages constraining LIS retreat at the maximum southern margin and the paucity of data in central New England, the timing of LIS retreat through this region is uncertain. Here, we date LIS retreat through south-central New England using 14 new in situ cosmogenic ¹⁰Be exposure ages measured in samples collected from bedrock and boulders. Our results suggest ice retreated entirely from Connecticut by 18.3 ± 0.3 ka (n = 3). In Massachusetts, exposure ages from similar latitudes suggest ice may have occupied the Hudson River Valley up to 2 kyr longer (15.2 ± 0.3 ka, average, n = 2) than the Connecticut River Valley (17.4 ± 1.0 ka, average, n = 5). We use these new ages to provide insight about LIS retreat timing during the early deglacial period and to explore the mismatch between radiocarbon and cosmogenic deglacial age chronologies in this region. Full article

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33 pages, 16462 KB

Open AccessEditor’s ChoiceArticle

Reappraisal and Analysis of Macroseismic Data for Seismotectonic Purposes: The Strong Earthquakes of Southern Calabria, Italy

by Carlo Andrenacci, Simone Bello, Maria Serafina Barbano, Rita de Nardis, Claudia Pirrotta, Federico Pietrolungo and Giusy Lavecchia

Geosciences 2023, 13(7), 212; https://doi.org/10.3390/geosciences13070212 - 14 Jul 2023

Cited by 11 | Viewed by 3066

Abstract

In tectonically active areas, such as the Italian peninsula, studying the faults responsible for strong earthquakes is often challenging, especially when the earthquakes occurred in historical times. In such cases, geoscientists need to integrate all the available information from historical reports, surface geology, [...] Read more.

In tectonically active areas, such as the Italian peninsula, studying the faults responsible for strong earthquakes is often challenging, especially when the earthquakes occurred in historical times. In such cases, geoscientists need to integrate all the available information from historical reports, surface geology, and geophysics to constrain the faults responsible for the earthquakes from a seismotectonic point of view. In this paper, we update and review, according to the EMS-98 scale, the macroseismic fields of the five main events of the 1783 Calabria sequence (5, 6, and 7 February, 1 and 28 March, M_w 5.9 to 7.1), two other destructive events within the same epicentral area of the 1783 sequence (1791, M_w 6.1 and 1894, M_w 6.1), plus the Messina Strait 1908 earthquake (M_w 7.1). For the 1783 seismic sequence, we also elaborate an updated and new catalog of coseismic effects. The new macroseismic fields were analyzed using a series of MATLAB algorithms to identify (1) the unitarity of the field or its partitioning in sub-sources and (2) the field and sub-fields’ main elongation. A collection of earthquake scale laws from literature was used to compute the average source parameters (length, width, and area) with their range of variability, and an elliptical map-view representation of the source geometry was calculated and made available. The analyses of such data allow us to speculate on the earthquakes/faults association, as well as propose new interpretations and reconstruct the space–time evolution of the significant southern Calabria seismic sequences in the last five centuries. Full article

(This article belongs to the Special Issue Geodynamics and Seismotectonics in the Mediterranean Region)

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26 pages, 5344 KB

Open AccessEditor’s ChoiceArticle

GEOAM: A Holistic Assessment Tool for Unveiling the Geoeducational Potential of Geosites

by George Zafeiropoulos and Hara Drinia

Geosciences 2023, 13(7), 210; https://doi.org/10.3390/geosciences13070210 - 13 Jul 2023

Cited by 14 | Viewed by 2693

Abstract

A new assessment method named GEOAM (geoeducational assessment method), that will be a useful tool for highlighting the geoeducational and geoethical value of a geosite, is proposed. This method takes into account, initially, 11 criteria, which are grouped into 8 categories. Each criterion [...] Read more.

A new assessment method named GEOAM (geoeducational assessment method), that will be a useful tool for highlighting the geoeducational and geoethical value of a geosite, is proposed. This method takes into account, initially, 11 criteria, which are grouped into 8 categories. Each criterion addresses a different aspect of the geosite’s potential for promoting sustainable development, environmental management, and education. A simplified scoring system using a scale of 1–5 is used, where each criterion is scored based on the degree to which it is presented or implemented. The method was piloted in eight geotopes of the Kalymnos Island and five geotopes of the Nisyros Island, in the SE Aegean Sea, Greece. The implementation of this assessment method highlighted the geoeducational value of these geosites. Based on the criteria and subcriteria incorporated in GEOAM, this paper discusses GEOAM’s potential to promote sustainable development and rational environmental management by directing educators and stakeholders toward actions that conserve and protect geoheritage for future generations, while also contributing to the economic, social, and cultural development of the surrounding communities. By quantifying the geoeducational potential of geosites and integrating essential concepts such as geoconservation and geoethics, the implementation of this new assessment method can benefit the educational community, tourism industry, and environmental conservation efforts. Full article

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

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16 pages, 4717 KB

Open AccessEditor’s ChoiceArticle

A Python Application for Visualizing an Imbricate Thrust System: Palomeque Duplex (SE, Spain)

by Manuel Bullejos and Manuel Martín-Martín

Geosciences 2023, 13(7), 207; https://doi.org/10.3390/geosciences13070207 - 11 Jul 2023

Cited by 4 | Viewed by 3278

Abstract

This paper introduces a Python application for visualizing an imbricate thrust system. The application uses the traditional geologic information to create an HTML geological map with real topography and a set of geological cross-sections with the essential structural and stratigraphic elements. On the [...] Read more.

This paper introduces a Python application for visualizing an imbricate thrust system. The application uses the traditional geologic information to create an HTML geological map with real topography and a set of geological cross-sections with the essential structural and stratigraphic elements. On the basis of the high geological knowledge gained during the last three decades, the Palomeque sheets affecting the Cenozoic Malaguide succession in the Internal Betic Zone (SE Spain) were selected to show the application. In this area, a Malaguide Cretaceous to Lower Miocene succession is deformed as an imbricate thrust system, with two thrusts forming a duplex, affected later by a set of faults with a main strike-slip kinematic. The modeled elements match well with the design of the stratigraphic intervals and the structures reported in recent scientific publications. This proves the good performance of this Python application for visualizing the structural and stratigraphic architecture. This kind of application could be a crucial stage for future groundwater, mining, and civil engineering management. Full article

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

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25 pages, 38419 KB

Open AccessEditor’s ChoiceArticle

Analysing Civilian Video Footage for Enhanced Scientific Understanding of the 2011 Tohoku Earthquake and Tsunami, Japan, with Implications for PNG and Pacific Islands

by Caitlin Mcdonough-Margison, Graham Hinchliffe and Michael G. Petterson

Geosciences 2023, 13(7), 203; https://doi.org/10.3390/geosciences13070203 - 3 Jul 2023

Cited by 5 | Viewed by 4286

Abstract

Approximately 70% of global tsunamis are generated within the pan Pacific Ocean region. This paper reports on detailed analysis of civilian video footage from the 2011 Tohoku earthquake, Japan. Comprehensive scientific analysis of tsunami video footage can yield valuable insights into geophysical processes [...] Read more.

Approximately 70% of global tsunamis are generated within the pan Pacific Ocean region. This paper reports on detailed analysis of civilian video footage from the 2011 Tohoku earthquake, Japan. Comprehensive scientific analysis of tsunami video footage can yield valuable insights into geophysical processes and impacts. Civili22an video footage captured during the 2011 Tohoku, East Honshu, Japan tsunami was critically examined to identify key tsunami processes and estimate local inundation heights and flow velocity in Kesennuma City. Significant tsunami processes within the video were captured and orientated in ArcGIS Pro to create an OIC (Oriented Imagery Catalogue). The OIC was published to ArcGIS Online, and the oriented imagery was configured into an interactive website. Flow velocity was estimated by quantifying the distance and time taken for an object to travel between two known points in the video. Estimating inundation height was achieved by taking objects with known or calculable dimensions and measuring them against maximum local inundation height observations. The oriented imagery process produced an interactive Experience Builder app in ArcGIS Online, highlighting key tsunami processes captured within the video. The estimations of flow velocity and local inundation height quantified during video analysis indicate flow speeds ranging from 2.5–4.29 m/s and an estimated maximum local run-up height of 7.85 m in Kesennuma City. The analysis of civilian video footage provides a remarkable opportunity to investigate tsunami impact in localised areas of Japan and around the world. These data and analyses inform tsunami hazard maps, particularly in reasonably well-mapped terrains with remote access to landscape data. The results can aid in the understanding of tsunami behaviours and help inform effective mitigation strategies in tsunami-vulnerable areas. The affordable, widely accessible analysis and methodology presented here has numerous applications, and does not require highly sophisticated equipment. Tsunamis are a significant to major geohazard globally including many Pacific Island states, e.g., Papua New Guinea, Solomon Islands, and Tonga. Video footage geoscientific analysis, as here reported, can benefit tsunami and cyclone storm surge hazards in the Pacific Islands region and elsewhere. Full article

(This article belongs to the Special Issue Geoscience, Exploration and Extraction: Empowering Geoscience for Inclusive Growth and Sustainable Development)

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30 pages, 22673 KB

Open AccessEditor’s ChoiceArticle

Is the Earth’s Magnetic Field a Constant? A Legacy of Poisson

by Jean-Louis Le Mouël, Fernando Lopes, Vincent Courtillot, Dominique Gibert and Jean-Baptiste Boulé

Geosciences 2023, 13(7), 202; https://doi.org/10.3390/geosciences13070202 - 1 Jul 2023

Cited by 4 | Viewed by 13643

Abstract

In the report he submitted to the Académie des Sciences, Poisson imagined a set of concentric spheres at the origin of Earth’s magnetic field. It may come as a surprise to many that Poisson as well as Gauss both considered the magnetic field [...] Read more.

In the report he submitted to the Académie des Sciences, Poisson imagined a set of concentric spheres at the origin of Earth’s magnetic field. It may come as a surprise to many that Poisson as well as Gauss both considered the magnetic field to be constant. We propose in this study to test this surprising assertion for the first time, evoked by Poisson in 1826. First, we present a development of Maxwell’s equations in the framework of a static electric field and a static magnetic field in order to draw the necessary consequences for the Poisson hypothesis. In a second step, we see if the observations can be in agreement with Poisson. To do so, we choose to compare (1) the polar motion drift and the secular variation of Earth’s magnetic field, (2) the seasonal pseudo-cycles of day length together with those of the sea level recorded by different tide gauges around the globe and those of Earth’s magnetic field recorded in different magnetic observatories. We then propose a mechanism, in the spirit of Poisson, to explain the presence of the 11-year cycle in the magnetic field. We test this mechanism with observations, and finally, we study closely the evolution of the

g_{1, 0}

coefficient of the International Geomagnetic Reference Field (IGRF) over time. Full article

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29 pages, 7520 KB

Open AccessEditor’s ChoiceArticle

Internal Friction Angle of Cohesionless Binary Mixture Sand–Granular Rubber Using Experimental Study and Machine Learning

by Firas Daghistani, Abolfazl Baghbani, Hossam Abuel Naga and Roohollah Shirani Faradonbeh

Geosciences 2023, 13(7), 197; https://doi.org/10.3390/geosciences13070197 - 28 Jun 2023

Cited by 14 | Viewed by 5125

Abstract

This study aimed to examine the shear strength characteristics of sand–granular rubber mixtures in direct shear tests. Two different sizes of rubber and one of sand were used in the experiment, with the sand being mixed with various percentages of rubber (0%, 10%, [...] Read more.

This study aimed to examine the shear strength characteristics of sand–granular rubber mixtures in direct shear tests. Two different sizes of rubber and one of sand were used in the experiment, with the sand being mixed with various percentages of rubber (0%, 10%, 20%, 30%, and 50%). The mixtures were prepared at three different densities (loose, slightly dense, and dense), and shear stress was tested at four normal stresses (30, 55, 105, and 200 kPa). The results of 80 direct shear tests were used to calculate the peak and residual internal friction angles of the mixtures, and it was found that the normal stress had a significant effect on the internal friction angle, with an increase in normal stress leading to a decrease in the internal friction angle. These results indicated that the Mohr–Coulomb theory, which applies to rigid particles only, is not applicable in sand–rubber mixtures, where stiff particles (sand) and soft particles (rubber) are mixed. The shear strength of the mixtures was also influenced by multiple factors, including particle morphology (size ratio, shape, and gradation), mixture density, and normal stress. For the first time in the literature, genetic programming, classification and regression random forests, and multiple linear regression were used to predict the peak and residual internal friction angles. The genetic programming resulted in the creation of two new equations based on mixture unit weight, normal stress, and rubber content. Both artificial intelligence models were found to be capable of accurately predicting the peak and residual internal friction angles of sand–rubber mixtures. Full article

(This article belongs to the Collection New Advances in Geotechnical Engineering)

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20 pages, 37108 KB

Open AccessEditor’s ChoiceArticle

Geologically-Driven Migration of Landmines and Explosive Remnants of War—A Feature Focusing on the Western Balkans

by Ivo Baselt, Adis Skejic, Budo Zindovic and Jens Bender

Geosciences 2023, 13(6), 178; https://doi.org/10.3390/geosciences13060178 - 14 Jun 2023

Cited by 4 | Viewed by 7166

Abstract

Landmines and explosive remnants of war are still present in the Western Balkans and remain a deadly legacy of the hostilities at the end of the 20th century. Over the years, several incidents have occurred in Bosnia and Herzegovina, in Serbia, and in [...] Read more.

Landmines and explosive remnants of war are still present in the Western Balkans and remain a deadly legacy of the hostilities at the end of the 20th century. Over the years, several incidents have occurred in Bosnia and Herzegovina, in Serbia, and in Croatia where intact ordnance has caused injuries and fatalities. Floods, torrential flows, and gravitational mass movements pose a particular threat. Landmines and explosive remnants of war are mobilized and displaced into previously uncontaminated areas. We first discuss the historical and technical background of this hazardous situation. We then show which hydro-morphological processes are responsible for the mobilization and displacement. We then illustrate how a prediction of the likely contaminated areas can be obtained. We show that the problem can only be tackled using a stochastic-deterministic model. However, for the eventual development of risk-hazard maps, preliminary work using laboratory experiments and field surveys is required. The article, therefore, proposes a novel approach to the problem in an international research project. The aim would be to produce risk-hazard maps that can be used by elected decision-makers, administrative authorities, and emergency personnel in affected municipalities. Full article

(This article belongs to the Section Natural Hazards)

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38 pages, 19437 KB

Open AccessEditor’s ChoiceReview

A Critical Review of Current States of Practice in Direct Shear Testing of Unfilled Rock Fractures Focused on Multi-Stage and Boundary Conditions

by Nicholas R. MacDonald, Timothy R. M. Packulak and Jennifer J. Day

Geosciences 2023, 13(6), 172; https://doi.org/10.3390/geosciences13060172 - 8 Jun 2023

Cited by 9 | Viewed by 11043

Abstract

Direct shear (DS) is a common geotechnical laboratory test used to determine strength and deformation properties of rock discontinuities, such as normal and shear stiffness, peak and residual shear strength, and dilation. These are used as inputs for discontinuous geomechanical numerical models to [...] Read more.

Direct shear (DS) is a common geotechnical laboratory test used to determine strength and deformation properties of rock discontinuities, such as normal and shear stiffness, peak and residual shear strength, and dilation. These are used as inputs for discontinuous geomechanical numerical models to simulate discontinuities discretely and shear strength is often expressed by Mohr–Coulomb, Patton, or Barton–Bandis constitutive models. This paper presents a critical review of the different boundary conditions and procedural techniques currently used in practice, summarizes previous contributions, addresses their impacts on interpreted results for rock engineering design, and introduces clarifying terminology for shear strength parameters. Based on the review, the authors advise that constant normal stress is best suited for discrete numerical-model-based rock engineering design in dry conditions, but constant normal stiffness should be considered where fluid permeability is of interest. Multi-stage testing should not be used to obtain peak shear strength values except for stage 1, because of accumulating asperity damage with successive shear stages. Nevertheless, if multi-stage testing must be employed due to limited budget or specimen availability, guidance is presented to improve shear strength results with limited displacement techniques. Full article

(This article belongs to the Section Geomechanics)

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21 pages, 15066 KB

Open AccessEditor’s ChoiceArticle

Sea Caves and Other Landforms of the Coastal Scenery on Gozo Island (Malta): Inventory and New Data on Their Formation

by Stefano Furlani, Fabrizio Antonioli, Emanuele Colica, Sebastiano D’Amico, Stefano Devoto, Pietro Grego and Timmy Gambin

Geosciences 2023, 13(6), 164; https://doi.org/10.3390/geosciences13060164 - 2 Jun 2023

Cited by 7 | Viewed by 4869

Abstract

Sea caves are a type of cave formed primarily by the wave action of the sea. The coastal scenery of the Gozitan coast is very interesting in that sea caves and other coastal landforms, such as sea arches, develop at the sea level. [...] Read more.

Sea caves are a type of cave formed primarily by the wave action of the sea. The coastal scenery of the Gozitan coast is very interesting in that sea caves and other coastal landforms, such as sea arches, develop at the sea level. We mapped seventy-nine semi-submerged sea caves opening at the sea level, five completely submerged sea caves, seven sea arches, one sea stack, and one shelter around the coast of Gozo, mainly in the Western and Eastern parts of the island, due to favorable lithological and topographical conditions. Additionally, we surveyed the topography of the emerged part of nine sea caves using the iPhone build-in LiDAR sensor, and eight sea caves in the submerged part using SCUBA equipment. This inventory represents the most detailed example of a database of coastal caves and related forms in the Mediterranean, mainly sourced from a swimming survey along the entire island. Thanks to the combination of outputs of the above-water emerged and submerged surveys, we defined three types of semi-submerged sea caves: (i) box caves, (ii) joint caves, and (iii) complex caves. Moreover, we added a cave-like landform above the sea level on calcarenites called shelter, or a little extended notch deeply carved into the cliff. The shape mainly depends on the structural and lithological setting of sea cliffs. In the Western sector of the island, we also discovered the only sea cave in Gozo, measuring 122 m in length and 10 m in width, with its floor developing above the mean sea level. This cave base is of interest due to rounded landforms related to marine erosion. In the innermost part of the cave, there is also a beach with rounded pebble at an elevation of about 7 m asl. Considering the tectonic stability of the island, it could be possibly related to the MIS 5.5 highstand. Full article

(This article belongs to the Special Issue Relative Sea-Level Rise)

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25 pages, 5753 KB

Open AccessEditor’s ChoiceArticle

Factors Contributing to the Long-Term Sea Level Trends in the Iberian Peninsula and the Balearic and Canary Islands

by Manuel Vargas-Yáñez, Elena Tel, Marta Marcos, Francina Moya, Enrique Ballesteros, Cristina Alonso and M. Carmen García-Martínez

Geosciences 2023, 13(6), 160; https://doi.org/10.3390/geosciences13060160 - 31 May 2023

Cited by 8 | Viewed by 5705

Abstract

We present an attempt to estimate the long-term changes in Relative Sea Level (RSL), in addition to the different factors contributing to such trends on a local and regional scale, using a statistical linear model. The time series analysis corresponded to 17 tide-gauges, [...] Read more.

We present an attempt to estimate the long-term changes in Relative Sea Level (RSL), in addition to the different factors contributing to such trends on a local and regional scale, using a statistical linear model. The time series analysis corresponded to 17 tide-gauges, grouped in three different areas: the northern and western Atlantic coasts of the Iberian Peninsula, the Canary Islands, and the southern and eastern coasts of the Iberian Peninsula and Balearic Islands. The analysis was performed for two periods: 1948–2019, using tide-gauge data; and 1993–2019, using both tide-gauge and altimetry data for comparison. The trends for the period 1948–2019 ranged between 1.09 ± 0.14 (Canary Islands) and 2.05 ± 0.21 mm/yr for the northern and western Atlantic Iberian Peninsula. Altimetry data during the period 1993–2019 yielded quite homogeneous results for all the locations and regions, ranging between 2.7 ± 0.4 and 3.0 ± 0.3 mm/yr. In contrast, the results obtained from tide-gauge data for this recent period showed a large dispersion, very likely due to local effects, or perhaps even to levelling or instrumental errors. Nevertheless, when the results were averaged for each area, the observed trends were comparable to the altimetry results, with values of 2.3 ± 0.8, 2.7 ± 0.5, and 2.8 ± 0.8 mm/yr for the three regions of study. A stepwise forward linear regression was used to relate the observed RSL variability to the atmospheric forcing and the thermosteric and halosteric components of the sea level. Surprisingly, the thermosteric and halosteric contributions were not significantly correlated to the observed RSL in many cases; consequently, the steric, the total addition of mass, the mass of salt, and the freshwater contributions to the observed sea level trends could not be reliably estimated. This result seems to have been the consequence of the scarcity of temperature and salinity data; this hypothesis was confirmed, with the exception of the tide-gauge data for L’Estartit. This location is close to a well sampled region. In this case, the atmospheric variables and the thermosteric and halosteric terms accounted for 80% of the observed RSL variance, and the contributions of these terms could be estimated. The freshwater contribution for this location was between 1.3 and 1.4 mm/yr, consistent with recent estimations of the contributions of glaciers and Greenland and Antarctica Ice Sheets. These results highlight the importance of monitoring programs and routine sampling for the determination of the different factors contributing to the sea level variability. Full article

(This article belongs to the Special Issue Relative Sea-Level Rise)

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36 pages, 14590 KB

Open AccessEditor’s ChoiceArticle

“Geo-Archaeo-Routes” on the Island of Lemnos: The “Nalture” Experience as a Holistic Geotouristic Approach within the Geoethical Perspective

by Maria V. Triantaphyllou, Nikolaos Firkasis, Theodora Tsourou, Emmanuel Vassilakis, Evangelos Spyrou, Olga Koukousioura, Argyro Oikonomou and Athanasios Skentos

Geosciences 2023, 13(5), 143; https://doi.org/10.3390/geosciences13050143 - 12 May 2023

Cited by 8 | Viewed by 6636

Abstract

The geosites of Lemnos represent local touristic products that, beyond their high aesthetic value, display significant scientific links to the geological past as well as prehistory and history, archaeology, mythology and religious heritage of the island. The unique wealth of Lemnos geosites in [...] Read more.

The geosites of Lemnos represent local touristic products that, beyond their high aesthetic value, display significant scientific links to the geological past as well as prehistory and history, archaeology, mythology and religious heritage of the island. The unique wealth of Lemnos geosites in combination with the abundance of archaeological sites, cultural monuments and museums composes the basis of what we define here as “Geo-Archaeo-Routes”: certain routes that can be geographically defined, offered, guided and finally followed by the touristic masses. The outcome of the performed quantitative Lemnos geosite assessment enables decision making, thus providing a toolbox useful for sustainable Geo-Archaeo-tourism development at a local level and forms the basis for designing “Geo-Archaeo-Routes”. “Geo-Archaeo-Routes” are particularly favorable of environmentally friendly alternative types of tourism, attracting naturalists, hikers, fans of cultural or religious tourism and many others who represent a major part of the touristic needs of the 21st century. The established hiking and road “Geo-Archaeo-Routes” on Lemnos Island may represent a distinctive touristic product as they offer a high level of “nalture” entertainment, blending “nature with culture” in the framework of a holistic geotouristic approach. Full article

(This article belongs to the Special Issue Geoheritage and Geotourism Resources: Education, Recreation, Sustainability II)

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35 pages, 33136 KB

Open AccessEditor’s ChoiceArticle

Numerical Modeling of an Asteroid Impact on Earth: Matching Field Observations at the Chicxulub Crater Using the Distinct Element Method (DEM)

by Tam N.-M. Duong, Billy Hernawan, Zenon Medina-Cetina and Jaime Urrutia Fucugauchi

Geosciences 2023, 13(5), 139; https://doi.org/10.3390/geosciences13050139 - 9 May 2023

Cited by 5 | Viewed by 7294

Abstract

In recent years, an international consortium of research organizations conducted investigations at the Chicxulub Crater in Yucatan, Mexico, to better understand the crater’s formation mechanisms and the effects produced by the impact of the asteroid that is hypothesized to have caused one of [...] Read more.

In recent years, an international consortium of research organizations conducted investigations at the Chicxulub Crater in Yucatan, Mexico, to better understand the crater’s formation mechanisms and the effects produced by the impact of the asteroid that is hypothesized to have caused one of the major life extinctions on Earth. This study aims to reproduce the asteroid’s impact mechanics by matching computer simulations obtained with the use of the distinct element method (DEM) against the latest topographic data observed across the crater footprint. A 2D model was formulated using ITASCA’s PFC2D software to reproduce the asteroid’s impact on Earth. The model ground conditions prior to impact were replicated based on available geological and geophysical field information. Also, the proposed DEM model configuration was designed to reproduce a far-field effect to ascertain the energy dissipation of the asteroid’s impact at the model’s boundaries. Impact conditions of the asteroid were defined based on previous asteroid impact investigations. A parametric analysis including the asteroid’s impact angle and the asteroid’s impact velocity was conducted to assess their influence on the crater formation process. Results of the simulations included the final crater topography and stratigraphy, stress profiles, contact force chains, and velocity fields. Numerical simulations showed that both the asteroid velocity and impact inclination play a major role in the crater formation process, and that the use of DEM provides interesting insights into impact crater formation. Full article

(This article belongs to the Topic Stochastic Geomechanics: From Experimentation to Forward Modeling)

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20 pages, 1983 KB

Open AccessEditor’s ChoiceArticle

Critical Failure Factors of Flood Early Warning and Response Systems (FEWRS): A Structured Literature Review and Interpretive Structural Modelling (ISM) Analysis

by Srimal Samansiri, Terrence Fernando and Bingunath Ingirige

Geosciences 2023, 13(5), 137; https://doi.org/10.3390/geosciences13050137 - 8 May 2023

Cited by 9 | Viewed by 6988

Abstract

Flood warning and response systems are essential components of risk reduction strategies with the potential to reduce loss of life and impact on personal assets. However, recent flood incidents have caused significant loss of human lives due to failures in current flood warning [...] Read more.

Flood warning and response systems are essential components of risk reduction strategies with the potential to reduce loss of life and impact on personal assets. However, recent flood incidents have caused significant loss of human lives due to failures in current flood warning and response mechanisms. These failures are broadly related to policies concerning, and governance aspects within, warning generation, the behaviour of communities in responding to early warnings, and weaknesses in associated tools and technologies used in communicating early warnings and responding. Capturing critical failure factors affecting flood warning and response systems can provide opportunities for making corrective measures and for developing a more advanced and futuristic system for early flood warnings. This paper reports the findings of a structured review that was conducted to identify critical failure factors in flood early warning and response systems. This study found twenty-four critical failure factors (CFFs). The interpretive structural modelling (ISM) approach conducted in this study resulted in identifying four different types of failure factors (autonomous, dependent, linkage, and independent) with varying dependence and driving powers. Analysis shows that governance, leadership, finance, standard operating procedures (SoP), and community engagement are the most dominating factors with the highest driving factor, which can overcome other dependent factors. The outcome of this review could be helpful for policymakers and practitioners in overcoming failure factors and implementing effective early warning and response systems. Full article

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27 pages, 9732 KB

Open AccessEditor’s ChoiceArticle

Geological Uniqueness and Potential Geotouristic Appeal of Murge and Premurge, the First Territory in Puglia (Southern Italy) Aspiring to Become a UNESCO Global Geopark

by Marcello Tropeano, Massimo A. Caldara, Vincenzo De Santis, Vincenzo Festa, Mario Parise, Luisa Sabato, Luigi Spalluto, Ruggero Francescangeli, Vincenzo Iurilli, Giuseppe A. Mastronuzzi, Marco Petruzzelli, Filippo Bellini, Marianna Cicala, Elio Lippolis, Fabio M. Petti, Matteo Antonelli, Stefano Cardia, Jacopo Conti, Rafael La Perna, Maria Marino, Antonella Marsico, Enrico Sacco, Antonello Fiore, Oronzo Simone, Salvatore Valletta, Umberto S. D’Ettorre, Vincenzo De Giorgio, Isabella S. Liso and Eliana Stigliano Show full author list Hide full author list

Geosciences 2023, 13(5), 131; https://doi.org/10.3390/geosciences13050131 - 30 Apr 2023

Cited by 17 | Viewed by 6164

Abstract

At the end of November 2021, a large area of Puglia (an administrative region in Southern Italy) was officially nominated as new aUGGp (aspiring UNESCO Global Geopark) by the Italian National Commission of UNESCO. This area comprises the northwestern part of the Murge [...] Read more.

At the end of November 2021, a large area of Puglia (an administrative region in Southern Italy) was officially nominated as new aUGGp (aspiring UNESCO Global Geopark) by the Italian National Commission of UNESCO. This area comprises the northwestern part of the Murge territory, where a Cretaceous sector of the Apulia Carbonate Platform crops out, and part of the adjacent Premurge territory, where the southwestward lateral continuation of the same platform (being flexed toward the Southern Apennines Chain) is covered by thin Plio-Quaternary foredeep deposits. The worldwide geological uniqueness of the aspiring Geopark (Murge aUGGp) is that the area is the only in situ remnant of the Adria Plate, the old continental plate almost entirely squeezed between the Africa and Eurasia Plates. In such a context, the Murge area (part of the Apulia Foreland) is a virtually undeformed sector of Adria, while other territories of the plate are and/or were involved in the subduction/collision processes. In the aspiring Geopark, the crust of Adria is still rooted to its mantle, and the Cretaceous evolution of the continent is widely recorded in the Murge area thanks to the shallow-water carbonate succession of one of the largest peri-Tethys carbonate platforms (the Apulia Carbonate Platform). The aspiring Geopark also comprises the Premurge area, which represents the outer Southern Apennines foredeep, whose Plio-Quaternary evolution is spectacularly exposed thanks to an “anomalous” regional middle-late Quaternary uplift. Despite the presence of numerous geological singularities of international importance, it would be important, from a geotourist point of view, to propose a regional framework of the geology of the aUGGp before introducing visitors to the significance of the individual geosites, whose importance could be amplified if included in the geoevolutionary context of the Murge aUGGp. Full article

(This article belongs to the Special Issue Geoheritage and Geotourism Resources: Education, Recreation, Sustainability II)

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14 pages, 2084 KB

Open AccessEditor’s ChoicePerspective

The Contributions of Marine Sediment Cores to Volcanic Hazard Assessments: Present Examples and Future Perspectives

by Chris Satow, Sebastian Watt, Mike Cassidy, David Pyle and Yuqiao Natalie Deng

Geosciences 2023, 13(4), 124; https://doi.org/10.3390/geosciences13040124 - 21 Apr 2023

Cited by 1 | Viewed by 4314

Abstract

The rigorous assessment of volcanic hazards relies on setting contemporary monitoring observations within an accurate, longer-term geological context. Revealing that geological context requires the detailed fieldwork, mapping and laboratory analysis of the erupted materials. However, many of the world’s most dangerous volcanic systems [...] Read more.

The rigorous assessment of volcanic hazards relies on setting contemporary monitoring observations within an accurate, longer-term geological context. Revealing that geological context requires the detailed fieldwork, mapping and laboratory analysis of the erupted materials. However, many of the world’s most dangerous volcanic systems are located on or near coasts (e.g., the Phlegraean Fields and Vesuvius in Italy), islands (e.g., the volcanic archipelagos of the Pacific, south-east Asia, and Eastern Caribbean), or underwater (e.g., the recently erupting Hunga Tonga–Hunga Ha’apai volcano), meaning that much of their erupted material is deposited on the sea bed. The only way to sample this material directly is with seafloor sediment cores. This perspectives paper outlines how marine sediment cores are a vital yet underused resource for assessing volcanic hazards by: (1) outlining the spatio-temporal scope of the marine volcanic record and its main deposit types, (2) providing existing examples where marine sediments have contributed to volcanic hazard assessments; (3) highlighting the Sunda Arc, Indonesia as an example location where marine sediment cores are yet to contribute to hazard assessments, and (4) proposing that marine sediment cores can contribute to our understanding of very large eruptions that have a global impact. Overall, this perspectives paper aims to promote the utility of marine sediment cores in future volcanic hazard assessments, while also providing some basic information to assist researchers who are considering integrating marine sediment cores into their volcanological research. Full article

(This article belongs to the Special Issue Marine Geohazards)

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19 pages, 11700 KB

Open AccessEditor’s ChoiceArticle

The First Rock Glacier Inventory for the Greater Caucasus

by Levan G. Tielidze, Alessandro Cicoira, Gennady A. Nosenko and Shaun R. Eaves

Geosciences 2023, 13(4), 117; https://doi.org/10.3390/geosciences13040117 - 13 Apr 2023

Cited by 9 | Viewed by 4951

Abstract

Rock glaciers are an integral part of the periglacial environment. At the regional scale in the Greater Caucasus, there have been no comprehensive systematic efforts to assess the distribution of rock glaciers, although some individual parts of ranges have been mapped before. In [...] Read more.

Rock glaciers are an integral part of the periglacial environment. At the regional scale in the Greater Caucasus, there have been no comprehensive systematic efforts to assess the distribution of rock glaciers, although some individual parts of ranges have been mapped before. In this study we produce the first inventory of rock glaciers from the entire Greater Caucasus region—Russia, Georgia, and Azerbaijan. A remote sensing survey was conducted using Geo-Information System (GIS) and Google Earth Pro software based on high-resolution satellite imagery—SPOT, Worldview, QuickBird, and IKONOS, based on data obtained during the period 2004–2021. Sentinel-2 imagery from the year 2020 was also used as a supplementary source. The ASTER GDEM (2011) was used to determine location, elevation, and slope for all rock glaciers. Using a manual approach to digitize rock glaciers, we discovered that the mountain range contains 1461 rock glaciers with a total area of 297.8 ± 23.0 km². Visual inspection of the morphology suggests that 1018 rock glaciers with a total area of 199.6 ± 15.9 km² (67% of the total rock glacier area) are active, while the remaining rock glaciers appear to be relict. The average maximum altitude of all rock glaciers is found at 3152 ± 96 m above sea level (a.s.l.) while the mean and minimum altitude are 3009 ± 91 m and 2882 ± 87 m a.s.l., respectively. We find that the average minimum altitude of active rock glaciers is higher (2955 ± 98 m a.s.l.) than in relict rock glaciers (2716 ± 83 m a.s.l.). No clear difference is discernible between the surface slope of active (41.4 ± 3°) and relict (38.8 ± 4°) rock glaciers in the entire mountain region. This inventory provides a database for understanding the extent of permafrost in the Greater Caucasus and is an important basis for further research of geomorphology and palaeoglaciology in this region. The inventory will be submitted to the Global Land Ice Measurements from Space (GLIMS) database and can be used for future studies. Full article

(This article belongs to the Special Issue Mountain Glaciers, Permafrost, and Snow)

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19 pages, 8946 KB

Open AccessEditor’s ChoiceArticle

Assessing 40 Years of Flood Risk Evolution at the Micro-Scale Using an Innovative Modeling Approach: The Effects of Urbanization and Land Planning

by Tommaso Lazzarin, Andrea Defina and Daniele Pietro Viero

Geosciences 2023, 13(4), 112; https://doi.org/10.3390/geosciences13040112 - 6 Apr 2023

Cited by 15 | Viewed by 4014

Abstract

The present work is aimed at assessing the change in time of flood risk as a consequence of landscape modifications. The town of San Donà di Piave (Italy) is taken as a representative case study because, as most parts of the North Italy [...] Read more.

The present work is aimed at assessing the change in time of flood risk as a consequence of landscape modifications. The town of San Donà di Piave (Italy) is taken as a representative case study because, as most parts of the North Italy floodplains, it was strongly urbanized and anthropized in the last several decades. As a proxy for flood risk, we use flood damage to residential buildings. The analysis is carried out at the local scale, accounting for changes to single buildings; GIS data such as high-resolution topography, technical maps, and aerial images taken over time are used to track how the landscape evolves over time, both in terms of urbanized areas and of hydraulically relevant structures (e.g., embankments). Flood hazard is determined using a physics-based, finite element hydrodynamic code that models in a coupled way the flood routing within the Piave River, the formation of levee failures, and the flooding of adjacent areas. The expected flood damage to residential buildings is estimated using an innovative method, recently proposed in the literature, which allows estimating how the damage evolves during a single flood event. The decade-scale change in the expected flood damage reveals the detrimental effect of urbanization, with flood risk growing at the pace of a fraction of urbanized areas. The within-event time evolution of the flood damage, i.e., how it progresses in the course of past or recent flood events, reflects changes in the hydrodynamic process of flooding. The general methodology used in the present work can be viewed as a promising technique to analyze the effects on the flood risk of past landscape evolution and, more importantly, a valuable tool toward an improved, well-informed, and sustainable land planning. Full article

(This article belongs to the Special Issue Flood Hazard and Risk in Urban Areas)

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18 pages, 8478 KB

Open AccessEditor’s ChoiceArticle

Shallow Geothermal Potential of the Sant’Eufemia Plain (South Italy) for Heating and Cooling Systems: An Effective Renewable Solution in a Climate-Changing Society

by Giovanni Vespasiano, Giuseppe Cianflone, Marco Taussi, Rosanna De Rosa, Rocco Dominici and Carmine Apollaro

Geosciences 2023, 13(4), 110; https://doi.org/10.3390/geosciences13040110 - 5 Apr 2023

Cited by 7 | Viewed by 3820

Abstract

In this work, the shallow geothermal heat-exchange potential of a coastal plain in southern Italy, the Sant’Eufemia plain (Calabria region), was evaluated. Stratigraphic and hydrogeological data and thermophysical properties of the main geological formations of the area have been averaged over the first [...] Read more.

In this work, the shallow geothermal heat-exchange potential of a coastal plain in southern Italy, the Sant’Eufemia plain (Calabria region), was evaluated. Stratigraphic and hydrogeological data and thermophysical properties of the main geological formations of the area have been averaged over the first 100 m of subsoil to define the thermal conductivity, the specific heat extraction rates of the ground and the geothermal potential of the area (MWh·y⁻¹) for both cooling and heating modes. The investigation revealed that the crystalline bedrock and the saturated conditions of the sedimentary infill mainly control the heat-exchange potential. The range of the geothermal potential in the investigated Sant’Eufemia plain is 3.61–10.56 MWh·y⁻¹ and 3.72–11.47 MWh·y⁻¹ for heating and cooling purposes, respectively. The average depth drilled to supply a standard domestic power demand of 5.0 kW is ~90 m for heating and ~81 m for cooling modes. The different depth also drives the final drilling costs, which range from EUR 3200 to 8700 for the heating mode and from EUR 2800 to 7800 for the cooling mode. Finally, the mean values of drilling depth and costs for both heating and cooling modes are provided for the main municipalities and strategic sites. Full article

(This article belongs to the Special Issue Geochemical Characterization of Geothermal Systems: Multidisciplinary Approaches to Define Source Processes, Evolution and Environmental Issues)

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18 pages, 3247 KB

Open AccessEditor’s ChoiceArticle

Subduction and Hydrogen Release: The Case of Bolivian Altiplano

by Isabelle Moretti, Patrice Baby, Paola Alvarez Zapata and Rosmar Villegas Mendoza

Geosciences 2023, 13(4), 109; https://doi.org/10.3390/geosciences13040109 - 4 Apr 2023

Cited by 9 | Viewed by 5064

Abstract

Natural hydrogen is known to be generated in the crust by water/rock interactions, especially the oxidation of iron-rich rock or radiolysis. However, other sources, especially deeper ones, exist. In the context of subduction, the dehydration of the slab, the destabilization of the NH [...] Read more.

Natural hydrogen is known to be generated in the crust by water/rock interactions, especially the oxidation of iron-rich rock or radiolysis. However, other sources, especially deeper ones, exist. In the context of subduction, the dehydration of the slab, the destabilization of the NH₄, and the hydration of the mantle wedge above the subducting lithosphere may generate H₂. We present here a compilation of the known gases in the central part of the Pacific subduction and the results of a first field acquisition dedicated to H₂ measurements in Bolivia between La Paz and South Lipez. Various zones have been studied: the emerging thrust faults of the western borders of the Eastern Cordillera, the Sajama area that corresponds to the western volcanic zone near the Chile border northward from the Uyuni Salar, and finally, the Altiplano-Puna Volcanic Complex in South Lipez. Soil gas measurement within and around the Salar itself was not fully conclusive. North of the Uyuni Salar, the gases are very rich in CO₂, enriched in N₂ and poor in H₂. On the opposite, southward, all the samples contain some H₂; the major gas is nitrogen, which may overpass 90% after air correction, and the CO₂ content is very limited. On the western border of the Cordillera, the δC13 isotope varies between −5 and −13‰_, and it is not surprisingly compatible with volcanic gas, as well as with asthenospheric CO₂. The methane content is close to 0, and only a few points reach 1%. The isotopes (−1‰) indicate an abiotic origin, and it is thus related to deep H₂ presence. The high steam flow in the geothermal area of South Lipez combined with the H₂ content in the water results in at least 1 ton of H₂ currently released per day from each well and may deserve an evaluation of its economic value. The nitrogen content, as in other subduction or paleo-subduction areas, questions the slab alteration. Full article

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28 pages, 6622 KB

Open AccessEditor’s ChoiceArticle

Earthquake, Fire, and Water: Destruction Sequence Identified in an 8th Century Early Islamic Harbor Warehouse in Caesarea, Israel

by Charles J. Everhardt IV, Hendrik W. Dey, Uzi ‘Ad, Jacob Sharvit, Peter Gendelman, Joel Roskin, Lotem Robins, Roy Jaijel, Ofra Barkai and Beverly N. Goodman-Tchernov

Geosciences 2023, 13(4), 108; https://doi.org/10.3390/geosciences13040108 - 4 Apr 2023

Cited by 3 | Viewed by 5332

Abstract

An 8th century CE earthquake severely damaged inland cities across the southern-central Levant, but reported evidence of this earthquake along the coastline is scarce. In Caesarea Maritima, archaeologists have found contemporaneous anomalous sand and shelly layers within nearshore structures and interpreted them as [...] Read more.

An 8th century CE earthquake severely damaged inland cities across the southern-central Levant, but reported evidence of this earthquake along the coastline is scarce. In Caesarea Maritima, archaeologists have found contemporaneous anomalous sand and shelly layers within nearshore structures and interpreted them as construction fill, aeolian accumulation, or abandonment debris. Recently, similar sand deposits were exposed in a Roman-to-Islamic harbor-side warehouse. This presented the first opportunity to directly sample and systematically analyze in situ, undisturbed deposits in order to determine their origin and taphonomic (source and transport) history. Two sediment cores from the deposit as well as comparative reference samples from defined contexts were analyzed for grain size distribution, foraminifera (abundance/taphonomy), and relative age (POSL, archaeochronology). The results support the interpretation that the deposit was formed from the transport of offshore marine sediments during a high-energy inundation event, most likely a tsunami associated with the 749 CE earthquake. Full article

(This article belongs to the Special Issue Marine Geohazards)

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50 pages, 11165 KB

Open AccessEditor’s ChoiceArticle

Vein Formation and Reopening in a Cooling Yet Intermittently Pressurized Hydrothermal System: The Single-Intrusion Tongchang Porphyry Cu Deposit

by Xuan Liu, Antonin Richard, Jacques Pironon and Brian G. Rusk

Geosciences 2023, 13(4), 107; https://doi.org/10.3390/geosciences13040107 - 1 Apr 2023

Cited by 3 | Viewed by 5772

Abstract

Porphyry deposits are the dominant sources of copper and major sources of several base and precious metals. They are commonly formed via the repeated emplacement of hydrous magmas and associated fluid exsolution. As a result, mineralized hydrothermal veins may undergo multiple deposition and [...] Read more.

Porphyry deposits are the dominant sources of copper and major sources of several base and precious metals. They are commonly formed via the repeated emplacement of hydrous magmas and associated fluid exsolution. As a result, mineralized hydrothermal veins may undergo multiple deposition and reopening processes that are not fully accounted for by existing fluid models. The Tongchang porphyry Cu deposit is a rare example of being related to a single intrusion. The simplicity in intrusive history provides an ideal starting point for studying fluid processes in more complex multi-intrusion porphyry systems. Detailed scanning electron microscope (SEM) cathodoluminescence imaging (CL) revealed rich microtextures in quartz and anhydrite that point to a fluid timeline encompassing early quartz deposition followed by fluid-aided dynamic recrystallization, which was succeeded by an intermediate stage of quartz dissolution and subsequent deposition, and ended with a late stage of continuous quartz deposition, brecciation, and fracturing. Vein reopening is more common than expected. Fifteen out of seventeen examined vein samples contained quartz and/or anhydrite that was older or younger than the vein age defined by vein sequences. Thermobarometry and solubility analysis suggests that the fluid events occurred in a general cooling path (from 650 °C to 250 °C), interspersed with two episodes of fluid pressurization. The first episode occurred at high-T (>500 °C), under lithostatic conditions alongside dynamic recrystallization, whereas the second one took place at a lower temperature (~400 °C), under lithostatic to hydrostatic transition conditions. The main episode of chalcopyrite veining took place subsequent to the second overpressure episode at temperatures of 380–300 °C. The results of this study reaffirm that thermal and hydraulic conditions are the main causative factors for vein reopening and growth in porphyry deposits. Full article

(This article belongs to the Special Issue Mineralogy and Geochemistry of Critical Metal-Bearing Mineral Deposits)

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16 pages, 5302 KB

Open AccessEditor’s ChoiceArticle

Teaching Geology in Higher Education Institutions under COVID-19 Conditions

by Georgios Giotopoulos, Dimitrios Papoulis, Ioannis Koukouvelas, Irini Skopeliti, Polychronis Economou and Eleni Gianni

Geosciences 2023, 13(4), 96; https://doi.org/10.3390/geosciences13040096 - 24 Mar 2023

Cited by 1 | Viewed by 4336

Abstract

Teaching geology under COVID-19 pandemic conditions led to teaching limitations for educators and learning difficulties for students. The lockdown obstructed face-to-face teaching, laboratory work, and fieldtrips. To minimize the impact of this situation, new distance learning teaching methods and tools were developed. The [...] Read more.

Teaching geology under COVID-19 pandemic conditions led to teaching limitations for educators and learning difficulties for students. The lockdown obstructed face-to-face teaching, laboratory work, and fieldtrips. To minimize the impact of this situation, new distance learning teaching methods and tools were developed. The current study presents the results of an empirical study, where distance learning teaching tools were constructed and used to teach geology to university students. A mineralogical mobile phone application was used to replace laboratory mineral identification and a flow chart to replace laboratory rock identification. Additionally, exercises on faults and maps were developed to fill the gap that was created as field work was impossible. A university course on geology was designed on the basis of the constructed distance learning teaching tools, and more than 100 students from the Department of Civil Engineering attended the course. The results show that the proposed tools helped the students to considerably understand scientific information on geology and supported the learning outcomes. Thus, it is suggested that the teaching tools, constructed for the purposes of the study, could be used in conditions when distance learning is required, or even under typical learning conditions after laboratories, as well as before or after fieldtrips, for better learning outcomes. Full article

(This article belongs to the Collection Education in Geosciences)

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23 pages, 2340 KB

Open AccessEditor’s ChoiceArticle

Reinforcement Learning for the Face Support Pressure of Tunnel Boring Machines

by Enrico Soranzo, Carlotta Guardiani and Wei Wu

Geosciences 2023, 13(3), 82; https://doi.org/10.3390/geosciences13030082 - 13 Mar 2023

Cited by 10 | Viewed by 4190

Abstract

In tunnel excavation with boring machines, the tunnel face is supported to avoid collapse and minimise settlement. This article proposes the use of reinforcement learning, specifically the deep Q-network algorithm, to predict the face support pressure. The algorithm uses a neural network to [...] Read more.

In tunnel excavation with boring machines, the tunnel face is supported to avoid collapse and minimise settlement. This article proposes the use of reinforcement learning, specifically the deep Q-network algorithm, to predict the face support pressure. The algorithm uses a neural network to make decisions based on the expected rewards of each action. The approach is tested both analytically and numerically. By using the soil properties ahead of the tunnel face and the overburden depth as the input, the algorithm is capable of predicting the optimal tunnel face support pressure whilst minimising settlement, and adapting to changes in geological and geometrical conditions. The algorithm reaches maximum performance after 400 training episodes and can be used for random geological settings without retraining. Full article

(This article belongs to the Special Issue Benchmarks of AI in Geotechnics and Tunnelling)

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25 pages, 9682 KB

Open AccessEditor’s ChoiceArticle

Nisyros Aspiring UNESCO Global Geopark: Crucial Steps for Promoting the Volcanic Landscape’s Unique Geodiversity

by Paraskevi Nomikou, Dimitrios Panousis, Elisavet Nikoli, Varvara Antoniou, Dimitrios Emmanouloudis, Georgios Pehlivanides, Marios Agiomavritis, Panagiotis Nastos, Emma Cieslak-Jones and Aris Batis

Geosciences 2023, 13(3), 70; https://doi.org/10.3390/geosciences13030070 - 1 Mar 2023

Cited by 4 | Viewed by 3884

Abstract

Nisyros Geopark, an island geopark in the Southeastern Aegean Sea, Greece, is here presented as an official candidate for the UNESCO Global Geoparks designation, featuring outstanding geological, natural and cultural characteristics tightly connected to its volcanic origin. It covers a total area of [...] Read more.

Nisyros Geopark, an island geopark in the Southeastern Aegean Sea, Greece, is here presented as an official candidate for the UNESCO Global Geoparks designation, featuring outstanding geological, natural and cultural characteristics tightly connected to its volcanic origin. It covers a total area of 481 km² and includes Nisyros, an active volcano and the main island, the surrounding islets of Pachia, Strongyli, Pergousa, Kandeliousa and the marine region among them. It features 24 geosites and a network of well-established walking trails. Furthermore, there are two internationally designated Natura 2000 areas covering its entire surface and also exceptional archaeological and cultural sites, including fortresses, remnants of ancient habituations and numerous churches and monasteries. It is the only area in the broader region of the Eastern Mediterranean that hosts all these features within such a restricted area. The initial efforts of the management body of Nisyros Geopark and its scientific team to promote its unique geodiversity included the complete design, construction and launch of the official website, the mobile application “Nisyros Volcano App’’, a modern informative leaflet regarding the region of the hydrothermal craters (Lakki), a Geopark guidebook and a series of panels and signs for the geosites. Full article

(This article belongs to the Special Issue Geoheritage and Geotourism Resources: Education, Recreation, Sustainability II)

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20 pages, 6293 KB

Open AccessEditor’s ChoiceReview

Big Data, Small Island: Earth Observations for Improving Flood and Landslide Risk Assessment in Jamaica

by Cheila Avalon-Cullen, Christy Caudill, Nathaniel K. Newlands and Markus Enenkel

Geosciences 2023, 13(3), 64; https://doi.org/10.3390/geosciences13030064 - 24 Feb 2023

Cited by 9 | Viewed by 5097

Abstract

The Caribbean region is highly vulnerable to multiple hazards. Resultant impacts may be derived from single or multiple cascading risks caused by hydrological-meteorological, seismic, geologic, or anthropological triggers, disturbances, or events. Studies suggest that event records and data related to hazards, risk, damage, [...] Read more.

The Caribbean region is highly vulnerable to multiple hazards. Resultant impacts may be derived from single or multiple cascading risks caused by hydrological-meteorological, seismic, geologic, or anthropological triggers, disturbances, or events. Studies suggest that event records and data related to hazards, risk, damage, and loss are limited in this region. National Disaster Risk Reduction (DRR) planning and response require data of sufficient quantity and quality to generate actionable information, statistical inferences, and insights to guide continual policy improvements for effective DRR, national preparedness, and response in both time and space. To address this knowledge gap, we review the current state of knowledge, data, models, and tools, identifying potential opportunities, capacity needs, and long-term benefits for integrating Earth Observation (EO) understanding, data, models, and tools to further enhance and strengthen the national DRR framework using two common disasters in Jamaica: floods and landslides. This review serves as an analysis of the current state of DRR management and assess future opportunities. Equally, to illustrate and guide other United Nations Disaster Risk Reduction (UNDRR) priority countries in the Pacific region, known as Small Island Developing States (SIDS), to grapple with threats of multiple and compounding hazards in the face of increasing frequency, intensity, and duration of extreme weather events, and climate change impact. Full article

(This article belongs to the Special Issue Scientific Assessment of Recent Natural Hazard Events)

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21 pages, 5996 KB

Open AccessEditor’s ChoiceReview

Shoreline Change and Coastal Erosion in West Africa: A Systematic Review of Research Progress and Policy Recommendation

by Johnson Ankrah, Ana Monteiro and Helena Madureira

Geosciences 2023, 13(2), 59; https://doi.org/10.3390/geosciences13020059 - 17 Feb 2023

Cited by 24 | Viewed by 10012

Abstract

Shoreline change and coastal erosion resulting from natural events such as sea level rise and negative anthropogenic activities continue to be problems in many of the world’s coastal regions. Many coastal socio-ecological systems have become vulnerable as a result, especially in developing countries [...] Read more.

Shoreline change and coastal erosion resulting from natural events such as sea level rise and negative anthropogenic activities continue to be problems in many of the world’s coastal regions. Many coastal socio-ecological systems have become vulnerable as a result, especially in developing countries with less adaptive capacity. We utilized the systematic method to understand the research progress and policy recommendations on shoreline change and coastal erosion in West Africa. A total of 113 documents were retrieved from Scopus and the Web of Sciences databases, and 43 documents were eligible following established criteria. It was revealed that research on shoreline change and coastal erosion has progressed substantially since 1998, with most research studies originating from the Ghanaian territory. Again, most of the shoreline change and erosion problems in West Africa result from natural events such as sea level rise. However, there was evidence of anthropogenic influences such as sand mining, dam construction, and human encroachment causing shoreline change and erosion in the region. Research in the region has also progressed in terms of methodological approaches. Since 2004, researchers have utilized remote sensing and GIS techniques to source and analyze shoreline change and erosion. However, a combination of remote sensing and field observation approaches is required to clearly depict the erosion problems and aid policy direction. The overall call to action regarding policy recommendations revolves around improving coastal adaptation measures and the resilience of communities, instituting proper coastal zone management plans, and improving shoreline change and coastal erosion research. To protect lives and property, policymakers in the region need to set up good coastal zone management plans, strengthen adaptation measures, and make coastal communities more resistant to possible risks. Full article

(This article belongs to the Special Issue Shoreline Dynamics and Beach Erosion, 2nd Edition)

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31 pages, 27108 KB

Open AccessEditor’s ChoiceReview

The Importance of Rock Mass Damage in the Kinematics of Landslides

by Davide Donati, Doug Stead and Lisa Borgatti

Geosciences 2023, 13(2), 52; https://doi.org/10.3390/geosciences13020052 - 9 Feb 2023

Cited by 12 | Viewed by 5067

Abstract

The stability and kinematics of rock slopes are widely considered to be functions of lithological, structural, and environmental features. Conversely, slope damage features are often overlooked and considered as byproducts of slope deformation. This paper analyzes and discusses the potential role of slope [...] Read more.

The stability and kinematics of rock slopes are widely considered to be functions of lithological, structural, and environmental features. Conversely, slope damage features are often overlooked and considered as byproducts of slope deformation. This paper analyzes and discusses the potential role of slope damage, its time-dependent nature, and its control on both the stability of rock slopes and their kinematics. The analysis of several major landslides and unstable slopes, combined with a literature survey, shows that slope damage can play an important role in controlling short- and long-term slope stability. Seasonal and continuously active events cause permanent deformation within the slope due to the accumulation of slope damage features, including rock mass dilation and intact rock fracturing. Rock mass quality, lithology, and scale control the characteristics and complexity of slope damage, as well as the failure mechanism. The authors propose that the role of slope damage in slope kinematics should always be considered in slope stability analysis, and that an integrated characterization–monitoring–numerical modelling approach can enhance our understanding of slope damage, its evolution, and the controlling factors. Finally, it is emphasized that there is currently a lack of guidelines or frameworks for the quantitative assessment and classification of slope damage, which requires a multidisciplinary approach combining rock mechanics, geomorphology, engineering geology, remote sensing, and geophysics. Full article

(This article belongs to the Special Issue Landslide Behavior: From Monitoring to Kinematic Characterization through Both Traditional and Innovative Approaches)

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21 pages, 5955 KB

Open AccessEditor’s ChoiceArticle

High-Resolution Lidar-Derived DEM for Landslide Susceptibility Assessment Using AHP and Fuzzy Logic in Serdang, Malaysia

by Jude Okoli, Haslinda Nahazanan, Faten Nahas, Bahareh Kalantar, Helmi Zulhaidi Mohd Shafri and Zailani Khuzaimah

Geosciences 2023, 13(2), 34; https://doi.org/10.3390/geosciences13020034 - 28 Jan 2023

Cited by 27 | Viewed by 5385

Abstract

Landslide impact is potentially hazardous to an urban environment. Landslides occur at certain slope levels over time and require practical slope analysis to assess the nature of the slope where a landslide is likely to occur. Thus, acquiring very high-resolution remote sensing data [...] Read more.

Landslide impact is potentially hazardous to an urban environment. Landslides occur at certain slope levels over time and require practical slope analysis to assess the nature of the slope where a landslide is likely to occur. Thus, acquiring very high-resolution remote sensing data plays a significant role in determining the slope surface. For this study, 12 landslide conditioning parameters with 10 × 10 cell sizes that have never been previously collectively applied were created. These factors were created directly from the LiDAR (Light Detection and Ranging) DEM (digital elevation model)using their layer toolboxes, which include slope, aspect, elevation, curvature, and hill shade. Stream power index (SPI), topographic wetness index (TWI), and terrain roughness index (TRI) were created from spatial layers such as slope, flow direction, and flow accumulation. Shapefiles of distances to roads, lakes, trees, and build-up were digitized as land use/cover from the LiDAR image and produced using the Euclidean distance method in ArcGIS. The parameters were selected based on expert knowledge, previous landslide literature, and the study area characteristics. Moreover, multicriteria decision-making analysis, which includes the analytic hierarchy process (AHP) and fuzzy logic approaches not previously utilized with a LiDAR DEM, was used in this study to predict the possibility of a landslide. The receiver operating characteristics (ROC) were used for the validation of results. The area under the curve (AUC) values obtained from the ROC method for the AHP and fuzzy were 0.859 and 0.802, respectively. The final susceptibility results will be helpful to urban developers in Malaysia and for sustainable landslide hazard mitigation. Full article

(This article belongs to the Special Issue Soil Erosion and Shallow Landslides: Prediction of the Phenomena and Measures of Sediments Delivery)

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18 pages, 10158 KB

Open AccessEditor’s ChoiceArticle

Berriasian–Valanginian Geochronology and Carbon-Isotope Stratigraphy of the Yellow Cat Member, Cedar Mountain Formation, Eastern Utah, USA

by Robert M. Joeckel, Celina A. Suarez, Noah M. McLean, Andreas Möller, Gregory A. Ludvigson, Marina B. Suarez, James I. Kirkland, Joseph Andrew, Spencer Kiessling and Garrett A. Hatzell

Geosciences 2023, 13(2), 32; https://doi.org/10.3390/geosciences13020032 - 26 Jan 2023

Cited by 8 | Viewed by 9023

Abstract

The Early Cretaceous Yellow Cat Member of the terrestrial Cedar Mountain Formation in Utah, USA. has been interpreted as a “time-rich” unit because of its dinosaur fossils, prominent paleosols, and the results of preliminary chemostratigraphic and geochronologic studies. Herein, we refine prior interpretations [...] Read more.

The Early Cretaceous Yellow Cat Member of the terrestrial Cedar Mountain Formation in Utah, USA. has been interpreted as a “time-rich” unit because of its dinosaur fossils, prominent paleosols, and the results of preliminary chemostratigraphic and geochronologic studies. Herein, we refine prior interpretations with: (1) a new composite C-isotope chemostratigraphic profile from the well-known Utahraptor Ridge dinosaur site, which exhibits δ¹³C features tentatively interpreted as the Valanginian double-peak carbon isotope excursion (the so-called “Weissert Event”) and some unnamed Berriasian features; and (2) a new cryptotephra zircon eruption age of 135.10 ± 0.30/0.31/0.34 Ma (2σ) derived from the CA-ID-TIMS U-Pb analyses of zircons from a paleosol cryptotephra. Our interpretations of δ¹³C features on our chemostratigraphic profile, in the context of our new radiometric age, are compatible with at least one prior age model for the “Weissert Event” and the most recent revision of the Cretaceous time scale. Our results also support the interpretation that the Yellow Cat Member records a significant part of Early Cretaceous time. Full article

(This article belongs to the Special Issue Terrestrial Paleoclimatology and Paleohydrology of the Cretaceous Greenhouse World)

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16 pages, 5039 KB

Open AccessEditor’s ChoiceArticle

Assessment of the Record-Breaking 2020 Rainfall in Guinea-Bissau and Impacts of Associated Floods

by Orlando Mendes and Marcelo Fragoso

Geosciences 2023, 13(2), 25; https://doi.org/10.3390/geosciences13020025 - 20 Jan 2023

Cited by 12 | Viewed by 5415

Abstract

The impacts of Climate Change are quite visible in Guinea-Bissau. Greater irregularity at the beginning and end of the rainy season, as well as in relation to the interannual variability of precipitation, are evidence that shows these phenomena in West African countries and [...] Read more.

The impacts of Climate Change are quite visible in Guinea-Bissau. Greater irregularity at the beginning and end of the rainy season, as well as in relation to the interannual variability of precipitation, are evidence that shows these phenomena in West African countries and particularly in Guinea-Bissau, where the agriculture is rain-fed. The year 2020 was characterized as very rainy in comparison to the climatological average of 1981–2020, with positive anomalies throughout the country, despite the late arrival of the wet season, which usually occurs in May. July, August, and September 2020 were the rainiest months, registering above a normal frequency of days with precipitation greater than 50 mm. Bissau, the capital, registered a record-breaking annual rainfall and monthly amounts higher than the 90th and 95th percentiles in July and August, respectively. This heavy rain accompanied by strong winds caused flooding in several urban areas and agricultural fields, and the destruction of roads, houses, and infrastructures in different cities across the country. As a way of mitigating these impacts, the government, through the Ministry of Solidarity, made available 100 million CFA francs (6.5 million euros) to help families that were victims of the floods. Full article

(This article belongs to the Special Issue Scientific Assessment of Recent Natural Hazard Events)

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25 pages, 13991 KB

Open AccessEditor’s ChoiceArticle

On the Annual and Semi-Annual Components of Variations in Extent of Arctic and Antarctic Sea-Ice

by Fernando Lopes, Vincent Courtillot, Dominique Gibert and Jean-Louis Le Mouël

Geosciences 2023, 13(1), 21; https://doi.org/10.3390/geosciences13010021 - 16 Jan 2023

Cited by 4 | Viewed by 16961

Abstract

In this paper, the 1978–2022 series of northern (NHSI) and southern (SHSI) hemisphere sea ice extent are submitted to singular spectral analysis (SSA). The trends are quasi-linear, decreasing for NHSI (by 58,300 km

^{2}

/yr) and increasing for SHSI (by 15,400 km

^{2}

[...] Read more.

In this paper, the 1978–2022 series of northern (NHSI) and southern (SHSI) hemisphere sea ice extent are submitted to singular spectral analysis (SSA). The trends are quasi-linear, decreasing for NHSI (by 58,300 km

^{2}

/yr) and increasing for SHSI (by 15,400 km

^{2}

/yr). The amplitude of annual variation in the Antarctic is double that in the Arctic. The semi-annual components are in quadrature. The first three oscillatory components of both NHSI and SHSI, at 1, 1/2, and 1/3 yr, account for more than 95% of the signal variance. The trends are respectively 21 (Antarctic) and 4 times (Arctic) less than the amplitudes of the annual components. We next analyze variations in pole position (PM for polar motion, coordinates

m_{1}

,

m_{2}

) and length of day (lod). Whereas the SSA of the lod is dominated by the same first three components as sea ice, the SSA of the PM contains only the 1-yr forced annual oscillation and the Chandler 1.2-yr component. The 1-yr component of NHSI is in phase with that of the lod and in phase opposition with m₁, while the reverse holds for the 1-yr component of SHSI. The semi-annual component appears in the lod and not in

m_{1}

. The annual and semi-annual components of NHSI and SHSI are much larger than the trends, leading us to hypothesize that a geophysical or astronomical forcing might be preferable to the generally accepted forcing factors. The lack of modulation of the largest (SHSI) forced component does suggest an alternate mechanism. In Laplace’s theory of gravitation, the torques exerted by the Moon, Sun, and planets play the leading role as the source of forcing (modulation), leading to changes in the inclination of the Earth’s rotation axis and transferring stresses to the Earth’s envelopes. Laplace assumes that all masses on and in the Earth are set in motion by astronomical forces; more than variations in eccentricity, it is variations in the inclination of the rotation axis that lead to the large annual components of melting and re-freezing of sea-ice. Full article

(This article belongs to the Section Cryosphere)

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14 pages, 3247 KB

Open AccessEditor’s ChoiceArticle

Not Every Circle Is a Crater: Kettle Hole Size Distributions and Their Implications in Planetary Surface Age Dating

by Mackenzie Day, Jordan M. Bretzfelder and Duyen Le

Geosciences 2023, 13(1), 18; https://doi.org/10.3390/geosciences13010018 - 10 Jan 2023

Cited by 2 | Viewed by 6434

Abstract

Circular landscape features, including kettle lakes, sinkholes, pingos, calderas, and craters, develop from a variety of different geomorphic processes on Earth. On many rocky extraterrestrial surfaces, including Mars, the most common circular landscape features are craters, and the density of these craters is [...] Read more.

Circular landscape features, including kettle lakes, sinkholes, pingos, calderas, and craters, develop from a variety of different geomorphic processes on Earth. On many rocky extraterrestrial surfaces, including Mars, the most common circular landscape features are craters, and the density of these craters is commonly used to estimate the age of the surface. On planetary bodies where fluvial, volcanic, and glacial geomorphic processes are not present, alternative interpretations of circular features can safely be ignored. However, Mars once hosted an Earth-like climate and many elements of the Martian landscape that are visible today were formed by ancient fluvial, glacial, or volcanic processes. In this work, we focus on the potential presence of postglacial kettle hole depressions on Mars. We explore the size and density distribution of kettle lakes in three analog postglacial landscapes on Earth and discuss the implications for planetary surface age dating if kettles and craters are present together in the landscape on Mars. Full article

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17 pages, 4515 KB

Open AccessEditor’s ChoiceArticle

Near-Surface Geophysical Characterization of Lithologies in Corfu and Lefkada Towns (Ionian Islands, Greece)

by John D. Alexopoulos, Nicholas Voulgaris, Spyridon Dilalos, Vasileios Gkosios, Ioannis-Konstantinos Giannopoulos, Georgia S. Mitsika, Emmanuel Vassilakis, Vassilis Sakkas and George Kaviris

Geosciences 2022, 12(12), 446; https://doi.org/10.3390/geosciences12120446 - 3 Dec 2022

Cited by 5 | Viewed by 3612

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 V_S30 values. Full article

(This article belongs to the Special Issue Recent Advances in Surface Wave Imaging)

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46 pages, 8683 KB

Open AccessEditor’s ChoiceArticle

Development and Dynamics of Sediment Waves in a Complex Morphological and Tidal Dominant System: Southern Irish Sea

by Shauna Creane, Mark Coughlan, Michael O’Shea and Jimmy Murphy

Geosciences 2022, 12(12), 431; https://doi.org/10.3390/geosciences12120431 - 23 Nov 2022

Cited by 9 | Viewed by 4822

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 KB

Open AccessEditor’s ChoiceReview

Why Engineers Should Not Attempt to Quantify GSI

by Beverly Yang and Davide Elmo

Geosciences 2022, 12(11), 417; https://doi.org/10.3390/geosciences12110417 - 11 Nov 2022

Cited by 16 | Viewed by 8095

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 KB

Open AccessEditor’s ChoiceReview

Shoreline Change Analysis along Rivers and Deltas: A Systematic Review and Bibliometric Analysis of the Shoreline Study Literature from 2000 to 2021

by Munshi Khaledur Rahman, Thomas W. Crawford and Md Sariful Islam

Geosciences 2022, 12(11), 410; https://doi.org/10.3390/geosciences12110410 - 8 Nov 2022

Cited by 19 | Viewed by 3963

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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