Open AccessArticle
Present Glaciers and Their Dynamics in the Arid Parts of the Altai Mountains
Geosciences 2017, 7(4), 117; doi:10.3390/geosciences7040117 (registering DOI) -
Abstract
This research is based on multiyear in-situ observations, analysis of satellite and aerial imagery, meteorological data, and mass balance index calculations. Presently, 659 glaciers cover a total area of 322.1 km2. We identified four favorable, two neutral, and five unfavorable longer
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This research is based on multiyear in-situ observations, analysis of satellite and aerial imagery, meteorological data, and mass balance index calculations. Presently, 659 glaciers cover a total area of 322.1 km2. We identified four favorable, two neutral, and five unfavorable longer intervals of glacier development since 1940. A decelerating of glacial retreat took place in the 1960s and in the late 1980s/early 1990s. The strong decline in glacial mass between 1995 and 2009 resulted in a fast reduction of the glacial area (0.9% year−1 on the northern slope of Tavan Bogd, 1.5% year−1 at Mongun-Taiga), mostly due to the degradation of small glaciers; after 2009, the glacial loss slowed down. Large valley glaciers behaved asynchronously until recently, when their retreat accelerated rapidly reaching in some cases over 40 m∙year−1. Degradation of the accumulation zone and separation of the debris-covered parts of the glaciers are characteristic for the glacial retreat in the region of research. The time of reaction of the fronts of four valley glaciers of Mongun-Taiga and the northern slope of Tavan Bogd on climatic fluctuations is estimated between 11 and 20 years. Over the next decade, high rates of glacial degradation are expected. Full article
Open AccessArticle
Implementation of Tsunami Evacuation Maps at Setubal Municipality, Portugal
Geosciences 2017, 7(4), 116; doi:10.3390/geosciences7040116 -
Abstract
The Setubal municipality, Portugal, has diversified land use along its coastline (mostly located in a low-lying area): on the west there are beaches; the centre is dominated by a densely populated downtown; and the east has an important industrial area. Although the seismic
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The Setubal municipality, Portugal, has diversified land use along its coastline (mostly located in a low-lying area): on the west there are beaches; the centre is dominated by a densely populated downtown; and the east has an important industrial area. Although the seismic activity in mainland Portugal is moderate, considering the variety of exposed elements, the objectives of this study are to present and discuss the implementation of tsunami evacuation maps at Setubal municipality. Thus, tsunami numerical modelling was carried out by considering the 1969 tsunami and the 1755 tsunami scenarios. The model results show that the first tsunami wave arrived within 30–40 min of the earthquake. The inundation depth was up to 9 m at the beaches, 4.9 m downtown, and 4.0 m in the industrial area. These velocities are too dangerous if beach users are caught by the tsunami waves, even in a moderate scenario. Therefore, coastal communities must evacuate the inundated zones to high ground before the arrival of the first tsunami wave. For this reason, tsunami evacuation maps were created, indicating the quickest and safest routes to the meeting points, located on high ground and outside of the inundation zones. Full article
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Open AccessArticle
A Study of Ground Movements in Brussels (Belgium) Monitored by Persistent Scatterer Interferometry over a 25-Year Period
Geosciences 2017, 7(4), 115; doi:10.3390/geosciences7040115 -
Abstract
The time series of Synthetic Aperture Radar data acquired by four satellite missions (including ERS, Envisat, TerraSAR-X and Sentinel 1) were processed using Persistent Scatterer interferometric synthetic aperture radar (InSAR) techniques. The processed datasets provide a nearly continuous coverage from 1992 to 2017
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The time series of Synthetic Aperture Radar data acquired by four satellite missions (including ERS, Envisat, TerraSAR-X and Sentinel 1) were processed using Persistent Scatterer interferometric synthetic aperture radar (InSAR) techniques. The processed datasets provide a nearly continuous coverage from 1992 to 2017 over the Brussels Region (Belgium) and give evidence of ongoing, slow ground deformations. The results highlight an area of uplift located in the heart of the city, with a cumulative ground displacement of ±4 cm over a 25-year period. The rates of uplift appear to have decreased from 2 to 4 mm/year during the ERS acquisition period (1992–2006) down to 0.5–1 mm/year for the Sentinel 1 data (2014–2017). Uplift of the city centre is attributed to a reduction of groundwater extraction from the deeper (Cenozoic-Paleozoic) aquifers, related to the deindustrialization of the city centre since the 1970s. The groundwater levels attested by piezometers in these aquifers show a clear recharge trend which induced the uplift. Some areas of subsidence in the river valleys such as the Maelbeek can be related to the natural settlement of soft, young alluvial deposits, possibly increased by the load of buildings. Full article
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Open AccessArticle
Influence of Flow Velocity on Tsunami Loss Estimation
Geosciences 2017, 7(4), 114; doi:10.3390/geosciences7040114 -
Abstract
Inundation depth is commonly used as an intensity measure in tsunami fragility analysis. However, inundation depth cannot be taken as the sole representation of tsunami impact on structures, especially when structural damage is caused by hydrodynamic and debris impact forces that are mainly
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Inundation depth is commonly used as an intensity measure in tsunami fragility analysis. However, inundation depth cannot be taken as the sole representation of tsunami impact on structures, especially when structural damage is caused by hydrodynamic and debris impact forces that are mainly determined by flow velocity. To reflect the influence of flow velocity in addition to inundation depth in tsunami risk assessment, a tsunami loss estimation method that adopts both inundation depth and flow velocity (i.e., bivariate intensity measures) in evaluating tsunami damage is developed. To consider a wide range of possible tsunami inundation scenarios, Monte Carlo-based tsunami simulations are performed using stochastic earthquake slip distributions derived from a spectral synthesis method and probabilistic scaling relationships of earthquake source parameters. By focusing on Sendai (plain coast) and Onagawa (ria coast) in the Miyagi Prefecture of Japan in a case study, the stochastic tsunami loss is evaluated by total economic loss and its spatial distribution at different scales. The results indicate that tsunami loss prediction is highly sensitive to modelling resolution and inclusion of flow velocity for buildings located less than 1 km from the sea for Sendai and Onagawa of Miyagi Prefecture. Full article
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Open AccessArticle
Towards the Selection of an Optimal Global Geopotential Model for the Computation of the Long-Wavelength Contribution: A Case Study of Ghana
Geosciences 2017, 7(4), 113; doi:10.3390/geosciences7040113 -
Abstract
The selection of a global geopotential model (GGM) for modeling the long-wavelength for geoid computation is imperative not only because of the plethora of GGMs available but more importantly because it influences the accuracy of a geoid model. In this study, we propose
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The selection of a global geopotential model (GGM) for modeling the long-wavelength for geoid computation is imperative not only because of the plethora of GGMs available but more importantly because it influences the accuracy of a geoid model. In this study, we propose using the Gaussian averaging function for selecting an optimal GGM and degree and order (d/o) for the remove-compute-restore technique as a replacement for the direct comparison of terrestrial gravity anomalies and GGM anomalies, because ground data and GGM have different frequencies. Overall, EGM2008 performed better than all the tested GGMs and at an optimal d/o of 222. We verified the results by computing geoid models using Heck and Grüninger’s modification and validated them against GPS/trigonometric data. The results of the validation were consistent with those of the averaging process with EGM2008 giving the smallest standard deviation of 0.457 m at d/o 222, resulting in an 8% improvement over the previous geoid model. In addition, this geoid model, the Ghanaian Gravimetric Geoid 2017 (GGG 2017) may be used to replace second-order class II leveling, with an expected error of 6.8 mm/km for baselines ranging from 20 to 225 km. Full article
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Open AccessArticle
Possible Factors Promoting Car Evacuation in the 2011 Tohoku Tsunami Revealed by Analysing a Large-Scale Questionnaire Survey in Kesennuma City
Geosciences 2017, 7(4), 112; doi:10.3390/geosciences7040112 -
Abstract
Excessive car evacuation can cause severe traffic jams that can lead to large numbers of casualties during tsunami disasters. Investigating the possible factors that lead to unnecessary car evacuation can ensure smoother tsunami evacuations and mitigate casualty damages in future tsunami events. In
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Excessive car evacuation can cause severe traffic jams that can lead to large numbers of casualties during tsunami disasters. Investigating the possible factors that lead to unnecessary car evacuation can ensure smoother tsunami evacuations and mitigate casualty damages in future tsunami events. In this study, we quantitatively investigated the possible factors that promote car evacuation, including both necessary and unnecessary usages, by statistically analysing a large amount of data on actual tsunami evacuation behaviours surveyed in Kesennuma, where devastating damage occurred during the 2011 Tohoku Tsunami. A straightforward statistical analysis revealed a high percentage of car evacuations (approx. 50%); however, this fraction includes a high number of unnecessary usage events that were distinguished based on mode choice reasons. In addition, a binary logistic regression was conducted to quantitatively evaluate the effects of several factors and to identify the dominant factor that affected evacuation mode choice. The regression results suggested that the evacuation distance was the dominant factor for choosing car evacuation relative to other factors, such as age and sex. The cross-validation test of the regression model demonstrated that the considered factors were useful for decision making and the prediction of evacuation mode choice in the target area. Full article
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Open AccessArticle
Structure of Volatile Conduits beneath Gorely Volcano (Kamchatka) Revealed by Local Earthquake Tomography
Geosciences 2017, 7(4), 111; doi:10.3390/geosciences7040111 -
Abstract
Gorely is an active volcano located 75 km from Petropavlovsk-Kamchatsky, Kamchatka. In 2010–2015, it exhibited strong activity expressed by anomalously high gas emission. In 2013–2014, we deployed a temporary network consisting of 20 temporary seismic stations that operated for one year. We selected
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Gorely is an active volcano located 75 km from Petropavlovsk-Kamchatsky, Kamchatka. In 2010–2015, it exhibited strong activity expressed by anomalously high gas emission. In 2013–2014, we deployed a temporary network consisting of 20 temporary seismic stations that operated for one year. We selected 333 events with 1613 P-wave and 2421 S-wave arrival times to build the first tomographic model of this volcano. The seismic model was carefully verified using a series of synthetic tests. Our tomographic model provides a mechanism for volatile feeding of Gorely. An unexpected feature of the model was low Vp/Vs ratios; below 1.4 in some parts. One reason for such low Vp/Vs ratios is gas contamination due to magma degassing. In the central part of the model, directly underneath the Gorely crater, we observe a 2.5 km wide and 1.5 km thick seismic anomaly with a very high Vp/Vs ratio of up to 2. This may represent a magma reservoir with a high melt and/or volatile content. The upper limit of this anomaly, 2.5 km below the surface, may indicate the degassing level, which coincides with the most intense seismicity. Below this reservoir, we observe another columnar high Vp/Vs ratio anomaly. This can be interpreted as a conduit bringing magma and fluids from deeper sources. Full article
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Open AccessArticle
Slope Stability Assessment Using Trigger Parameters and SINMAP Methods on Tamblingan-Buyan Ancient Mountain Area in Buleleng Regency, Bali
Geosciences 2017, 7(4), 110; doi:10.3390/geosciences7040110 -
Abstract
The mapping of soil movement was examined by comparing an extension of the deterministic Soil Stability Index Mapping (SINMAP) method, and an overlay method with trigger parameters of soil movement. The SINMAP model used soil parameters in the form of the cohesion value
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The mapping of soil movement was examined by comparing an extension of the deterministic Soil Stability Index Mapping (SINMAP) method, and an overlay method with trigger parameters of soil movement. The SINMAP model used soil parameters in the form of the cohesion value (c), internal friction angle (φ), and hydraulic conductivity (ks) for the prediction of soil movement based on the factor of safety (FS), while the indirect method used a literature review and field observations. The weightings of soil movement trigger parameters in assessments were based on natural physical aspects: (1) slope inclination = 30%; (2) rock weathering = 15%; (3) geological structure = 20%; (4) rainfall = 15%; (5) groundwater potential = 7%; (6) seismicity = 3%; and (7) vegetation = 10%. The research area was located in the Buleleng district, in particular in the ancient mountain area of Buyan-Tamblingan, in the Sukasada sub-district. The hazard mapping gave a high and very high hazard scale. The SINMAP model gave a validation accuracy of 14.29%, while the overlay method with seven trigger parameters produced an accuracy of 71.43%. Based on the analysis of the very high and high hazard class and the validation of the landslide occurrence points, the deterministic method using soil parameters and water absorption gave a much lower accuracy than the overlay method with a study of soil motion trigger parameters. Full article
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Open AccessFeature PaperArticle
SARchaeology—Detecting Palaeochannels Based on High Resolution Radar Data and Their Impact of Changes in the Settlement Pattern in Cilicia (Turkey)
Geosciences 2017, 7(4), 109; doi:10.3390/geosciences7040109 -
Abstract
The fertile alluvial plain of Cilicia is bordered by the Taurus and Amanus mountain ranges to the west, north and east and the Mediterranean Sea to the south. Since the Neolithic Period, Plain Cilicia was an important interface between Anatolia and the Levant.
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The fertile alluvial plain of Cilicia is bordered by the Taurus and Amanus mountain ranges to the west, north and east and the Mediterranean Sea to the south. Since the Neolithic Period, Plain Cilicia was an important interface between Anatolia and the Levant. The alluvial plain is dominated by three rivers: Tarsus, Seyhan and Ceyhan. The avulsion history of the lower course of the rivers Seyhan and Ceyhan during the Holocene remains an unresolved issue. The knowledge about how former river courses have changed is essential for the identification of ancient toponyms with archaeological sites. The analysis of silted up riverbeds based on high-resolution digital elevation models (TanDEM-X) and historic satellite imagery (CORONA) in this paper provide the first indications for the reconstruction of former river channels. Further evidence is given by the evaluation of the settlement patterns from 3rd to 1st millennium BC. Full article
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Open AccessArticle
Nutrients and Heavy Metals Contamination in an Urban Estuary of Northern New Jersey
Geosciences 2017, 7(4), 108; doi:10.3390/geosciences7040108 -
Abstract
The Newark Bay Estuary in northern New Jersey contains one of the largest urban wetland complexes in the United States, but the majority of the wetlands and habitats have been lost due to urbanization and industrialization. Field and laboratory research was conducted to
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The Newark Bay Estuary in northern New Jersey contains one of the largest urban wetland complexes in the United States, but the majority of the wetlands and habitats have been lost due to urbanization and industrialization. Field and laboratory research was conducted to understand the impacts of human activities on the biogeochemistry of nutrients and heavy metals in the urban estuary. Concentrations of dissolved nutrients such as nitrate, ammonia, and phosphate were higher in the Hackensack River than in the Passaic River or the Newark Bay, while the Hackensack River was more deficient in dissolved oxygen. Sediment oxygen demand and mobilization of nutrients were higher in sediments with higher organic matter content as a result of microbial decomposition of organic matter. Heavy metals (Cr, Cu, Pb, and Zn) and organic matter were more enriched in finer sediment grains such as silt and clay. There were positive correlations among heavy metals as well as organic matter in sediments. The results suggest that fine grained sediments, which can be readily suspended and transported during tidal cycles, may play a significant role in biogeochemical cycling of nutrients and heavy metals in the urban estuary. It appears that the current sources of nutrients and heavy metals in the water and sediment of the Newark Bay Estuary are mainly domestic effluents from sewage treatment plants during non-storm periods as well as combined sewer overflows during storm events, but further research including more frequent and pervasive water and sediment quality monitoring during dry and wet periods is needed. Full article
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Open AccessArticle
Characteristics and Dynamics of a Large Sub-Tidal Sand Wave Field—Habitat for Pacific Sand Lance (Ammodytes personatus), Salish Sea, Washington, USA
Geosciences 2017, 7(4), 107; doi:10.3390/geosciences7040107 -
Abstract
Deep-water sand wave fields in the San Juan Archipelago of the Salish Sea and Pacific Northwest Washington, USA, have been found to harbor Pacific sand lance (PSL, Ammodytes personatus), a critical forage fish of the region. Little is known of the dynamics
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Deep-water sand wave fields in the San Juan Archipelago of the Salish Sea and Pacific Northwest Washington, USA, have been found to harbor Pacific sand lance (PSL, Ammodytes personatus), a critical forage fish of the region. Little is known of the dynamics of these sand waves and the stability of the PSL sub-tidal habitats. Therefore, we have undertaken an initial investigation to determine the dynamic conditions of a well-known PSL habitat in the San Juan Channel within the Archipelago using bottom sediment sampling, an acoustical doppler current profiling (ADCP) system, and multi-beam echo sounder (MBES) bathymetry. Our study indicates that the San Juan Channel sand wave field maintained its shape and bedforms geometry throughout the years it has been studied. Based on bed phase diagrams for channelized bedforms, the sand waves appear to be in a dynamic equilibrium condition. Sea level rise may change the current regime within the Archipelago and may alter some of the deep-water or sub-tidal PSL habitats mapped there. Our findings have global significance in that these dynamic bedforms that harbor PSL and sand-eels elsewhere along the west coast of North America and in the North Sea may also be in a marginally dynamic equilibrium condition and may be prone to alteration by sea level rise, indicating an urgency in locating and investigating these habitats in order to sustain the forage fish. Full article
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Open AccessArticle
Detecting Landscape Disturbance at the Nasca Lines Using SAR Data Collected from Airborne and Satellite Platforms
Geosciences 2017, 7(4), 106; doi:10.3390/geosciences7040106 -
Abstract
We used synthetic aperture radar (SAR) data collected over Peru’s Lines and Geoglyphs of the Nasca and Palpa World Heritage Site to detect and measure landscape disturbance threatening world-renowned archaeological features and ecosystems. We employed algorithms to calculate correlations between pairs of SAR
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We used synthetic aperture radar (SAR) data collected over Peru’s Lines and Geoglyphs of the Nasca and Palpa World Heritage Site to detect and measure landscape disturbance threatening world-renowned archaeological features and ecosystems. We employed algorithms to calculate correlations between pairs of SAR returns, collected at different times, and generate correlation images. Landscape disturbances even on the scale of pedestrian travel are discernible in correlation images generated from airborne, L-band SAR. Correlation images derived from C-band SAR data collected by the European Space Agency’s Sentinel-1 satellites also provide detailed landscape change information. Because the two Sentinel-1 satellites together have a repeat pass interval that can be as short as six days, products derived from their data can not only provide information on the location and degree of ground disturbance, but also identify a time window of about one to three weeks during which disturbance must have occurred. For Sentinel-1, this does not depend on collecting data in fine-beam modes, which generally sacrifice the size of the area covered for a higher spatial resolution. We also report on pixel value stretching for a visual analysis of SAR data, quantitative assessment of landscape disturbance, and statistical testing for significant landscape change. Full article
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Open AccessArticle
SAR Imaging of Archaeological Sites on Intertidal Flats in the German Wadden Sea
Geosciences 2017, 7(4), 105; doi:10.3390/geosciences7040105 -
Abstract
We show that high-resolution space-borne synthetic aperture radar (SAR) imagery with pixel sizes smaller than 1 m2 can be used to complement archaeological surveys on intertidal flats. After major storm surges in the 14th and 17th centuries (“Grote Mandrenke”), vast
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We show that high-resolution space-borne synthetic aperture radar (SAR) imagery with pixel sizes smaller than 1 m2 can be used to complement archaeological surveys on intertidal flats. After major storm surges in the 14th and 17th centuries (“Grote Mandrenke”), vast areas on the German North Sea coast were lost to the sea. Areas of settlements and historical farmland were buried under sediments for centuries, but when the surface layer is driven away under the action of wind, currents, and waves, they appear again on the Wadden Sea surface. However, frequent flooding and erosion of the intertidal flats make any archaeological monitoring a difficult task, so that remote sensing techniques appear to be an efficient and cost-effective instrument for any archaeological surveillance of that area. Space-borne SAR images clearly show remains of farmhouse foundations and of former systems of ditches, dating back to the times before the “Grote Mandrenke”. In particular, the very high-resolution acquisition (“staring spotlight”) mode of the TerraSAR/TanDEM-X satellites allows detecting various kinds of remains of historical land use at high precision. Moreover, SARs working at lower microwave frequencies (e.g., that on Radarsat-2) may complement archaeological surveys of historical cultural traces, some of which have been unknown so far. Full article
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Open AccessArticle
Geoarchaeological Core Prospection as a Tool to Validate Archaeological Interpretation Based on Geophysical Data at the Roman Settlement of Auritz/Burguete and Aurizberri/Espinal (Navarre)
Geosciences 2017, 7(4), 104; doi:10.3390/geosciences7040104 -
Abstract
Geophysical survey methods are broadly used to delimit and characterize archaeological sites, but the archaeological interpretation of geophysical data remains one of the challenges. Indeed, many scenarios can generate a similar geophysical response, and often interpretations can not be validated without access to
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Geophysical survey methods are broadly used to delimit and characterize archaeological sites, but the archaeological interpretation of geophysical data remains one of the challenges. Indeed, many scenarios can generate a similar geophysical response, and often interpretations can not be validated without access to the subsoil. In large geophysical surveys many anomalies are detected and validation through archaeological trenches can not be afforded. This paper analyses the validity of geoarchaeological core survey to check the archaeological interpretations based on geophysical results. The Roman site located at Auritz/Burguete and Aurizberri/Espinal (Navarre), provides a great case of study as many investigations have been carried out. After the gradiometer survey performed in 2013 a sediment core survey was designed. 132 cores were drilled using a hand-held coring machine and the sediments were analysed in situ. Site delimitation and archaeological interpretations based on magnetic data could be improved or corrected. In this regard, the core survey proved to be an useful methodology as many anomalies could be checked within reasonable time and resources. However, further geophysical investigations trough GPR revealed unexpected remains in areas where no archaeological deposits were identified through coring. Excavations showed poor conservation level in some of those areas, leading to thin archaeological deposits hard to identify at the cores. The sediment core survey, therefore, was proved to be inconclusive to delimit the archaeological site. Full article
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Open AccessReview
The Nature and Articulation of Ethical Codes on Tailings Management in South Africa
Geosciences 2017, 7(4), 101; doi:10.3390/geosciences7040101 -
Abstract
It is well recognized that the mining industry in South Africa is highly rated for its substantial contribution to the country’s economic growth, including employment and infrastructural development. It is also known that mining and ore processing activities potentially pose a severe threat
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It is well recognized that the mining industry in South Africa is highly rated for its substantial contribution to the country’s economic growth, including employment and infrastructural development. It is also known that mining and ore processing activities potentially pose a severe threat to public health and environmental well-being, in the way operations are carried out, mine wastes are disposed of (in dumps), local communities are relocated, mine management and the mining community, in general, perceive established environmental standards and etiquette. This paper examines ethical practices and norms in the South African mining industry, with particular reference to the management of tailings dams. We analyse the modes of articulation of the country’s regulatory instruments for tailings management, and review the corporate social responsibility (CSR) approach of leading mining companies. Despite decades of research and resulting recommendations on tailings management, it is concluded that the current legislations are largely ineffective, that the level of adherence by mine management and the mining community is low, and that the mechanisms for compliance monitoring is weak. New perspectives on legislative issues for unsolved problems in tailings handling are put forward, and directions for future research, indicated. Full article
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Open AccessArticle
Geometric Analysis on Stone Façades with Terrestrial Laser Scanner Technology
Geosciences 2017, 7(4), 103; doi:10.3390/geosciences7040103 -
Abstract
This article presents a methodology to process information from a Terrestrial Laser Scanner (TLS) from three dimensions (3D) to two dimensions (2D), and to two dimensions with a color value (2.5D), as a tool to document and analyze heritage buildings. Principally focused on
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This article presents a methodology to process information from a Terrestrial Laser Scanner (TLS) from three dimensions (3D) to two dimensions (2D), and to two dimensions with a color value (2.5D), as a tool to document and analyze heritage buildings. Principally focused on the loss of material in stone, this study aims at creating an evaluation method for loss control, taking into account the state of conservation of a building in terms of restoration, from studying the pathologies, to their identification and delimitation. A case study on the Cathedral of the Seu Vella de Lleida was completed, examining the details of the stone surfaces. This cathedral was affected by military use, periods of abandonment, and periodic restorations. Full article
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Open AccessArticle
Escape Burrowing of Modern Freshwater Bivalves as a Paradigm for Escape Behavior in the Devonian Bivalve Archanodon catskillensis
Geosciences 2017, 7(4), 102; doi:10.3390/geosciences7040102 -
Abstract
Many freshwater bivalves restore themselves to the sediment water interface after burial by upward escape burrowing. We studied the escape burrowing capacity of two modern unionoids, Elliptio complanata and Pyganodon cataracta and the invasive freshwater venerid Corbicula fluminea, in a controlled laboratory
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Many freshwater bivalves restore themselves to the sediment water interface after burial by upward escape burrowing. We studied the escape burrowing capacity of two modern unionoids, Elliptio complanata and Pyganodon cataracta and the invasive freshwater venerid Corbicula fluminea, in a controlled laboratory setting varying sediment grain size and burial depth. We found that the relatively streamlined E. complanata is a better escape burrower than the more obese P. cataracta. E. complanata is more likely to escape burial in both fine and coarse sand, and at faster rates than P. cataracta. However, successful escape from 10 cm burial, especially in fine sand, is unlikely for both unionoids. The comparatively small and obese C. fluminea outperforms both unionoids in terms of escape probability and escape time, especially when body size is taken into consideration. C. fluminea can escape burial depths many times its own size, while the two unionoids rarely escape from burial equivalent to the length of their shells. E. complanata, and particularly P. cataracta, are morphological paradigms for the extinct Devonian unionoid bivalve Archanodon catskillensis, common in riverine facies of the Devonian Catskill Delta Complex of the eastern United States. Our observations suggest that the escape burrowing capability of A. catskillensis was no better than that of P. cataracta. Archanodon catskillensis was likely unable to escape burial of more than a few centimeters of anastrophically deposited sediment. The long (up to 1 meter), vertical burrows that are associated with A. catskillensis, and interpreted to be its escape burrows, represent a response to episodic, small-scale sedimentation events due to patterns of repetitive hydrologic or weather-related phenomena. They are not a response to a single anastrophic event involving the influx of massive volumes of sediment. Full article
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Open AccessFeature PaperArticle
From Above and on the Ground: Geospatial Methods for Recording Endangered Archaeology in the Middle East and North Africa
Geosciences 2017, 7(4), 100; doi:10.3390/geosciences7040100 -
Abstract
The EAMENA (Endangered Archaeology of the Middle East and North Africa) project is a collaboration between the Universities of Leicester, Oxford and Durham; it is funded by the Arcadia Fund and the Cultural Protection Fund. This paper explores the development of the EAMENA
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The EAMENA (Endangered Archaeology of the Middle East and North Africa) project is a collaboration between the Universities of Leicester, Oxford and Durham; it is funded by the Arcadia Fund and the Cultural Protection Fund. This paper explores the development of the EAMENA methodology, and discusses some of the problems of working across such a broad region. We discuss two main case studies: the World Heritage site of Cyrene illustrates how the project can use satellite imagery (dating from the 1960s to 2017), in conjunction with published data to create a detailed set of database records for a single site and, in particular, highlights the impact of modern urban expansion across the region. Conversely, the Homs Cairns case study demonstrates how the EAMENA methodology also works at an extensive scale, and integrates image interpretation (using imagery dating from the 1960s to 2016), landuse mapping and field survey (2007–2010) to record and analyse the condition of hundreds of features across a small study region. This study emphasises the impact of modern agricultural and land clearing activities. Ultimately, this paper assesses the effectiveness of the EAMENA approach, evaluating its potential success against projects using crowd-sourcing and automation for recording archaeological sites, and seeks to determine the most appropriate methods to use to document sites and assess disturbances and threats across such a vast and diverse area. Full article
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Open AccessArticle
Optical Remote Sensing Potentials for Looting Detection
Geosciences 2017, 7(4), 98; doi:10.3390/geosciences7040098 -
Abstract
Looting of archaeological sites is illegal and considered a major anthropogenic threat for cultural heritage, entailing undesirable and irreversible damage at several levels, such as landscape disturbance, heritage destruction, and adverse social impact. In recent years, the employment of remote sensing technologies using
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Looting of archaeological sites is illegal and considered a major anthropogenic threat for cultural heritage, entailing undesirable and irreversible damage at several levels, such as landscape disturbance, heritage destruction, and adverse social impact. In recent years, the employment of remote sensing technologies using ground-based and/or space-based sensors has assisted in dealing with this issue. Novel remote sensing techniques have tackled heritage destruction occurring in war-conflicted areas, as well as illicit archeological activity in vast areas of archaeological interest with limited surveillance. The damage performed by illegal activities, as well as the scarcity of reliable information are some of the major concerns that local stakeholders are facing today. This study discusses the potential use of remote sensing technologies based on the results obtained for the archaeological landscape of Ayios Mnason in Politiko village, located in Nicosia district, Cyprus. In this area, more than ten looted tombs have been recorded in the last decade, indicating small-scale, but still systematic, looting. The image analysis, including vegetation indices, fusion, automatic extraction after object-oriented classification, etc., was based on high-resolution WorldView-2 multispectral satellite imagery and RGB high-resolution aerial orthorectified images. Google Earth© images were also used to map and diachronically observe the site. The current research also discusses the potential for wider application of the presented methodology, acting as an early warning system, in an effort to establish a systematic monitoring tool for archaeological areas in Cyprus facing similar threats. Full article
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Open AccessArticle
Validity of the Apatite/Merrillite Relationship in Evaluating the Water Content in the Martian Mantle: Implications from Shergottite Northwest Africa (NWA) 2975
Geosciences 2017, 7(4), 99; doi:10.3390/geosciences7040099 -
Abstract
Phosphates from the Martian shergottite NWA 2975 were used to obtain insights into the source and subsequence differentiation of the melt/melts. The crystallization of two generations of fluorapatite (F > Cl~OH and F-rich), chlorapatite and ferromerrillite-merrillite were reconstructed from TEM (Transmission Electron Microscopy)
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Phosphates from the Martian shergottite NWA 2975 were used to obtain insights into the source and subsequence differentiation of the melt/melts. The crystallization of two generations of fluorapatite (F > Cl~OH and F-rich), chlorapatite and ferromerrillite-merrillite were reconstructed from TEM (Transmission Electron Microscopy) and geochemical analyses. The research results indicated that the recognized volatiles budget of the two generations of fluorapatite was related to their magmatic origin. The apatite crystals crystallized from an evolved magma during its final differentiation and degassing stage. In turn, chlorapatite replaced ferromerrillite-merrillite and was not related to, mantle-derived shergottite magma. The relationship between merrillite and apatite indicates that apatite is most probably a product of merrillite reacting with fluids. REE (rare earth elements) pattern of Cl-apatite might point to an origin associated with exogenous fluids mixed with fluids exsolved from evolved magma. The study shows that, among the three types of apatite, only the fluorapatite (F > Cl~OH) is a reliable source for assessing the degree of Martian mantle hydration. The occurrence of apatite with merrillite requires detailed recognition of their relationship. Consequently, the automatic use of apatite to assess the water content of the magma source can lead to false assumptions if the origin of the apatite is not precisely determined. Full article
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