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  • 1
    Publication Date: 2018-07-27
    Description: Geosciences, Vol. 8, Pages 274: Cryomorphological Topographies in the Study of Ice Caves Geosciences doi: 10.3390/geosciences8080274 Authors: Manuel Gómez-Lende Manuel Sánchez-Fernández The current interest in ice caves requires that their varied manifestations be known as accurately as possible in view of their responses to a global change and also to their great potential as paleoenvironmental witnesses. This phenomenon has been known about for a long time but is still scarcely studied from the point of view of its cryological values and the evolution and distribution of many of their morphologies. For this, the development of cryomorphological topographies from traditional techniques to geodetic surveys with different tools, including terrestrial laser scanning, is one of the most current ways to characterize and quantify this type of cryospheric phenomena. It represents a new kind of periglacial cartography whose use is feasible in spite of the difficulties these environments present.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 2
    Publication Date: 2018-07-27
    Description: Geosciences, Vol. 8, Pages 272: Towards National Archaeological Mapping. Assessing Source Data and Methodology—A Case Study from Scotland Geosciences doi: 10.3390/geosciences8080272 Authors: Łukasz Banaszek Dave C. Cowley Mike Middleton While the National Record of the Historic Environment (NRHE) in Scotland contains valuable information on more than 170,000 archaeological monuments, it is clear that this dataset is conditioned by the disposition of past survey and changing parameters of data collection strategies over many decades. This highlights the importance of creating systematic datasets, in which the standards to which they were created are explicit, and against which the reliability of our knowledge of the material remains of the past can be assessed. This paper describes issues of data structure and reliability, then discussing the methodologies under development for expediting the progress of national-scale mapping with specific reference to the Isle of Arran. Preliminary outcomes of a recent archaeological mapping project of the island, which has been used to develop protocols for rapid large area mapping, are outlined. The primary sources for the survey were airborne laser scanning derivatives and orthophotographs, supplemented by field observation, and the project has more than doubled the number of known monuments of Arran. The survey procedures are described, followed by a discussion of the utility of ‘general purpose’ remote sensed datasets, focusing on the assessment of strengths and weaknesses for rapid mapping of large areas.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 3
    Publication Date: 2018-07-27
    Description: Geosciences, Vol. 8, Pages 273: The Caribbean’s Geotourism Potential and Challenges: A Focus on Two Islands in the Region Geosciences doi: 10.3390/geosciences8080273 Authors: Colmore S. Christian Geotourism is a relatively new concept in the tourism industry, a concept which apparently has not yet been formally embraced by Caribbean destinations. This paper, based primarily on a literature review supplemented by the first-hand knowledge of the author, who served for over a decade in the natural resource management and tourism sectors in the region, identifies some of the geotourism assets and assesses the geotourism potential of two selected Caribbean islands, namely the Commonwealth of Dominica and St. Lucia. Indications are that the islands of the region have outstanding geological formations, dormant and active volcanic zones and associated geomorphological features, and breath-taking terrestrial and marine landscapes, including deep river gorges and tall mountains, and beautiful beaches, which together constitute important geotourism assets. Currently, these resources are marketed and promoted as part of the region’s nature tourism attractions. The feasibility of incorporating geotourism as a component of this overall nature tourism thrust is explored in this paper. As a follow-up to this study a survey of tourism officials, natural resource professionals, and selected scientists of the region is proposed for the purpose of identifying the reasons and constraints preventing the Caribbean region from formally embracing geotourism, developing and promoting the geotourism resources of the region as a unique component of the overall tourism product.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 4
    Publication Date: 2018-07-29
    Description: Geosciences, Vol. 8, Pages 279: Detection of Stones in Marine Habitats Combining Simultaneous Hydroacoustic Surveys Geosciences doi: 10.3390/geosciences8080279 Authors: Svenja Papenmeier H. Christian Hass Exposed stones in sandy sublittoral environments are hotspots for marine biodiversity, especially for benthic communities. The detection of single stones is principally possible using sidescan-sonar (SSS) backscatter data. The data resolution has to be high to visualize the acoustic shadows of the stones. Otherwise, stony substrates will not be differentiable from other high backscatter substrates (e.g., gravel). Acquiring adequate sonar data and identifying stones in backscatter images is time consuming because it usually requires visual-manual procedures. To develop a more efficient identification and demarcation procedure of stone fields, sidescan sonar and parametric echo sound data were recorded within the marine protected area of “Sylt Outer Reef” (German Bight, North Sea). The investigated area (~5.900 km2) is characterized by dispersed heterogeneous moraine and marine deposits. Data from parametric sediment echo sounder indicate hyperbolas at the sediment surface in stony areas, which can easily be exported. By combining simultaneous recorded low backscatter data and parametric single beam data, stony grounds were demarcated faster, less complex and reproducible from gravelly substrates indicating similar high backscatter in the SSS data.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 5
    Publication Date: 2018-08-01
    Description: Geosciences, Vol. 8, Pages 287: A New Occurrence of Terrestrial Native Iron in the Earth’s Surface: The Ilia Thermogenic Travertine Case, Northwestern Euboea, Greece Geosciences doi: 10.3390/geosciences8080287 Authors: Christos Kanellopoulos Eugenia Valsami-Jones Panagiotis Voudouris Christina Stouraiti Robert Moritz Constantinos Mavrogonatos Panagiotis Mitropoulos Native iron has been identified in an active thermogenic travertine deposit, located at Ilia area (Euboea Island, Greece). The deposit is forming around a hot spring, which is part of a large active metallogenetic hydrothermal system depositing ore-bearing travertines. The native iron occurs in two shapes: nodules with diameter 0.4 and 0.45 cm, and angular grains with length up to tens of μm. The travertine laminae around the spherical/ovoid nodules grow smoothly, and the angular grains are trapped inside the pores of the travertine. Their mineral-chemistry is ultra-pure, containing, other than Fe, only Mn (0.34–0.38 wt.%) and Ni (≤0.05 wt.%). After evaluating all the possible environments where native iron has been reported up until today and taking under consideration all the available data concerning the study area, we propose two possible scenarios: (i) Ilia’s native iron has a magmatic/hydrothermal origin i.e., it is a deep product near the magmatic chamber or a peripheral cooling igneous body that was transferred during the early stages of the geothermal field evolution, from high temperature, reduced gas-rich fluids and deposited along with other metals in permeable structural zones, at shallow levels. Later on, it was remobilized and mechanically transferred and precipitated at the Ilia’s thermogenic travertine by the active lower temperatures geothermal fluids; (ii) the native iron at Ilia is remobilized from deep seated ophiolitic rocks, originated initially from reduced fluids during serpentinization processes; however, its mechanical transport seems less probable. The native iron mineral-chemistry, morphology and the presence of the other mineral phases in the same thermogenic travertine support both hypotheses.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 6
    Publication Date: 2018-08-04
    Description: Geosciences, Vol. 8, Pages 288: Development of a New Simulation Tool Coupling a 2D Finite Volume Overland Flow Model and a Drainage Network Model Geosciences doi: 10.3390/geosciences8080288 Authors: Javier Fernández-Pato Pilar García-Navarro Numerical simulation of mixed flows combining free surface and pressurized flows is a practical tool to prevent possible flood situations in urban environments. When dealing with intense storm events, the limited capacity of the drainage network conduits can cause undesirable flooding situations. Computational simulation of the involved processes can lead to better management of the drainage network of urban areas. In particular, it is interesting to simultaneuously calculate the possible pressurization of the pipe network and the surface water dynamics in case of overflow. In this work, the coupling of two models is presented. The surface flow model is based on two-dimensional shallow water equations with which it is possible to solve the overland water dynamics as well as the transformation of rainfall into runoff through different submodels of infiltration. The underground drainage system assumes mostly free surface flow that can be pressurized in specific situations. The pipe network is modeled by means of one-dimensional sections coupled with the surface model in specific regions of the domain, such as drains or sewers. The numerical techniques considered for the resolution of both mathematical models are based on finite volume schemes with a first-order upwind discretization. The coupling of the models is verified using laboratory experimental data. Furthermore, the potential usefulness of the approach is demonstrated using real flooding data in a urban environment.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 7
    Publication Date: 2018-08-04
    Description: Geosciences, Vol. 8, Pages 289: Multi-Wavelength High-Resolution Spectroscopy for Exoplanet Detection: Motivation, Instrumentation and First Results Geosciences doi: 10.3390/geosciences8080289 Authors: Serena Benatti Exoplanet research has shown an incessant growth since the first claim of a hot giant planet around a solar-like star in the mid-1990s. Today, the new facilities are working to spot the first habitable rocky planets around low-mass stars as a forerunner for the detection of the long-awaited Sun-Earth analog system. All the achievements in this field would not have been possible without the constant development of the technology and of new methods to detect more and more challenging planets. After the consolidation of a top-level instrumentation for high-resolution spectroscopy in the visible wavelength range, a huge effort is now dedicated to reaching the same precision and accuracy in the near-infrared. Actually, observations in this range present several advantages in the search for exoplanets around M dwarfs, known to be the most favorable targets to detect possible habitable planets. They are also characterized by intense stellar activity, which hampers planet detection, but its impact on the radial velocity modulation is mitigated in the infrared. Simultaneous observations in the visible and near-infrared ranges appear to be an even more powerful technique since they provide combined and complementary information, also useful for many other exoplanetary science cases.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 8
    Publication Date: 2018-06-12
    Description: Geosciences, Vol. 8, Pages 213: A Mathematics Inspired Notation of Scales in the Climate System Geosciences doi: 10.3390/geosciences8060213 Authors: Jörn Behrens Conducting integrated climate research with involvement of such diverse disciplines as mathematics, meteorology, oceanography, economics, geology, biology, social, and communication sciences poses great challenges to the underlying nomenclature and methodology. In this article, we give a definition of the notion of scales, which is a central term in the geosciences, but not so familiar to social sciences or economics. We start with defining agents, involved in a specific subject of study, determined by their attributes or states. We move on to understand processes and phenomena as maps and subsets of image sets. With this and the introduction of metrics, we can measure sizes of phenomena and processes and finally define scales. Several examples illustrate our definition. An attempt is made to motivate a notion of scale interaction. This concept has proved useful in an interdisciplinary teaching project.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 9
    Publication Date: 2018-06-06
    Description: Geosciences, Vol. 8, Pages 203: Response of Soils and Soil Ecosystems to the Pennsylvanian–Permian Climate Transition in the Upper Fluvial Plain of the Dunkard Basin, Southeastern Ohio, USA Geosciences doi: 10.3390/geosciences8060203 Authors: Daniel Hembree Jennifer Carnes Direct exposure of paleosols to the atmosphere during formation make them ideal for reconstructing paleoclimate. Paleosol and ichnofossil properties are dependently linked making it important to study them in tandem, to avoid errors in interpretation. Small scale studies (<1 km) yield high resolution data that can be used to assess allogenic processes through comparison of spatial and temporal trends. This study used field and laboratory analyses to gather data from Late Pennsylvanian to Early Permian Upper Monongahela and Lower Dunkard group paleosols on Ohio Route 33 in Meigs County, OH, USA. The physical and geochemical properties of the paleosols from the field sites indicate that channel migration was the primary control on paleosol formation in the study area, however, a clear climate signal was observed. The change in paleosol type and calculated mean annual precipitation (MAP) values indicate that the climate became more strongly seasonal and drier over the course of the Pennsylvanian–Permian transition with a temporary excursion to a more ever-wet climate with higher MAP, marked by the occurrence of the Waynesburg Coal at the Pennsylvanian–Permian boundary.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 10
    Publication Date: 2018-06-16
    Description: Geosciences, Vol. 8, Pages 220: Clay Mineral Suites in Submarine Mud Volcanoes in the Kumano Forearc Basin, Nankai Trough: Constraints on the Origin of Mud Volcano Sediments Geosciences doi: 10.3390/geosciences8060220 Authors: Akira Ijiri Koichi Iijima Urumu Tsunogai Juichiro Ashi Fumio Inagaki Clay mineralogy is an important characteristic of mud volcano sediments. This study determined the clay mineral compositions of sediment from two submarine mud volcanoes in the Kumano forearc basin, Nankai Trough, by X-ray diffraction analysis. Similar compositions dominated by smectite in the two mud volcanoes indicate that the mud volcanoes in the basin are rooted in the same source sequence. These clay mineral compositions differed from those in Pleistocene basin sediment, suggesting that the mud volcano sediment originated beneath the Pleistocene sediment. The illite content in the illite–smectite mixed layer averaged 32% in the mud volcano sediment, which implies that the sediment experienced temperatures above 60 °C that promoted the smectite-to-illite transformation. However, porewater extracted from the mud volcano sediment had Cl‒ concentrations roughly half that of seawater and proportional enrichment in 18O and depletion in D, indicating that dehydration reactions of clay minerals had previously occurred in a deeply buried sedimentary layer. The smectite and illite contents (<60%) in the clay-size fraction rule out in situ smectite dewatering as the cause of the dilution of Cl‒ in porewater. Thus, fluids derived from clay dewatering must have originated from deeper than the source of the mud volcano sediment.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 11
    Publication Date: 2018-06-18
    Description: Geosciences, Vol. 8, Pages 222: Potential Indicator Value of Subfossil Gastropods in Assessing the Ecological Health of the Middle and Lower Reaches of the Yangtze River Floodplain System (China) Geosciences doi: 10.3390/geosciences8060222 Authors: Giri Kattel Yongjiu Cai Xiangdong Yang Ke Zhang Xu Hao Rong Wang Xuhui Dong The lakes across China’s middle and lower reaches of the Yangtze River system have a long history of sustaining human pressures. These aquatic resources have been exploited for fisheries and irrigation over millennia at a magnitude of scales, with the result that many lakes have lost their ecological integrity. The consequences of these changes in the ecosystem health of lakes are not fully understood; therefore, a long-term investigation is urgently needed. Gastropods (aquatic snails) are powerful bio-indicators that link primary producers, herbivores, and detritivores associated with macrophytes and grazers of periphyton and higher-level consumers. They are sensitive to abrupt environmental change such as eutrophication, dehydration, flooding, and proliferation of toxicity in floodplain lake systems. The use of the remains of gastropod shells (subfossils) preserved in the sedimentary archives of the floodplain lakes of the middle and lower reaches of the Yangtze River system holds high significance, as their potential in environmental change has not been studied in detail in the past. Here, we aim to test the hypothesis that modern and sub-fossil gastropods in the sediments of the middle and lower reaches of the Yangtze River floodplains systems have significant value as bioindicators, as they have the ability to reveal health-gradients of lake-ecosystem change in the region.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 12
    Publication Date: 2018-06-22
    Description: Geosciences, Vol. 8, Pages 226: Geophysical Input to Improve the Conceptual Model of the Hydrogeological Framework of a Coastal Karstic Aquifer: Uley South Basin, South Australia Geosciences doi: 10.3390/geosciences8070226 Authors: Nara Somaratne Glyn Ashman Michelle Irvine Simon Mann A lack of closely spaced datasets on layer elevations, aquifer parameters, identification of areas with high recharge potential, dominant conduit porosity zones, and well defined boundary conditions hampers the ability of groundwater models to produce a reliable water balance. Typically, geological structure, aquifer properties, and groundwater heads are obtained from point measurements which are sparse. The drillhole information in aquifers is usually available at locations far apart, distances ranging from hundreds to thousands of meters. Furthermore, pump tests are usually conducted at limited locations and generalized to the aquifer. This limited knowledge leads to errors in the conceptual understanding of the aquifer. In this study, Airborne Electromagnetic Survey (AEM) was used to define base elevations of the aquifers where drillhole information was lacking. Surface Nuclear Magnetic Resonance (sNMR), borehole NMR, Transient Electromagnetic (TEM), and downhole geophysical surveys have given new insight to the conceptualization of hydrogeological framework. These methods are relatively low in cost compared to traditional well drilling and provide information on layer elevations, aquifer parameters, point and diffuse recharge zones, and conduit porosity zones in the profile, which improves our definition of the boundary conditions. From a practical point of view, combining drillhole information with a variety of geophysical techniques provides sound datasets to develop a comprehensive conceptual model. This in turn can be used to build a robust groundwater model.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 13
    Publication Date: 2018-06-24
    Description: Geosciences, Vol. 8, Pages 233: Site Effect Assessment of the Gros-Morne Hill Area in Port-au-Prince, Haiti, Part B: Mapping and Modelling Results Geosciences doi: 10.3390/geosciences8070233 Authors: Sophia Ulysse Dominique Boisson Claude Prépetit Hans-Balder Havenith This paper presents the general results in terms of maps, as well as geological and numerical models of a site effect study, that aimed at a better understanding of the ground motion amplification on the Gros-Morne hill, in the southeastern part of Port-au-Prince, Haiti, which might have influenced the 2010 event damage pattern in that area. These maps and models are based on multiple geophysical–seismological survey outputs that are presented, in detail, in Part A of this publication. Those outputs include electrical resistivity tomography sections, P-wave velocity profiles, S-wave logs, estimates of the fundamental resonance frequency for many locations, as well as earthquake recordings at three sites and associated site amplification assessment for the top of the hill. Related results are discussed in Part A with respect to outputs and interpretations that had been published earlier by other research teams for the same site. Our results only partly confirm the strong seismic amplification effects highlighted by some of the previous studies for this hill site, which had been attributed to the influence of local topographic and soil characteristics on seismic ground motion. Here, we focus on the imaging of different site effect components over the entire survey area; we present maps of shear wave velocity variations, of changing fundamental resonance frequencies, and of related estimates of soft soil/rock thickness, of peak spectral amplitudes, and of ambient ground motion polarization. Results have also been compiled within a 3D surface–subsurface model of the hill, which helps visualize the geological characteristics of the area, which are relevant for site effect analyses. From the 3D geomodel, we extracted one 2D geological section along the short-axis of the hill, crossing it near the location of Hotel Montana on top of the hill, which had been destroyed during the earthquake, and has now been rebuilt. This cross-section was used for dynamic numerical modelling of seismic ground motion, and for related site amplification calculation. The numerical results are compared with the site amplification characteristics that had been estimated from the ambient vibration measurements and the earthquake recordings.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 14
    Publication Date: 2018-08-09
    Description: Geosciences, Vol. 8, Pages 298: Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions Geosciences doi: 10.3390/geosciences8080298 Authors: Vladimir Cheptsov Elena Vorobyova Andrey Belov Anatoly Pavlov Denis Tsurkov Vladimir Lomasov Sergey Bulat One of the prior current astrobiological tasks is revealing the limits of microbial resistance to extraterrestrial conditions. Much attention is paid to ionizing radiation, since it can prevent the preservation and spread of life outside the Earth. The aim of this research was to study the impact of accelerated electrons (~1 MeV) as component of space radiation on microbial communities in their natural habitat—the arid soil and ancient permafrost, and also on the pure bacterial cultures that were isolated from these ecotopes. The irradiation was carried out at low pressure (~0.01 Torr) and low temperature (−130 °C) to simulate the conditions of Mars or outer space. High doses of 10 kGy and 100 kGy were used to assess the effect of dose accumulation in inactive and hypometabolic cells, depending on environmental conditions under long-term irradiation estimated on a geological time scale. It was shown that irradiation with accelerated electrons in the applied doses did not sterilize native samples from Earth extreme habitats. The data obtained suggests that viable Earth-like microorganisms can be preserved in the anabiotic state for at least 1.3 and 20 million years in the regolith of modern Mars in the shallow subsurface layer and at a 5 m depth, respectively. In addition, the results of the study indicate the possibility of maintaining terrestrial like life in the ice of Europa at a 10 cm depth for at least ~170 years or for at least 400 thousand years in open space within meteorites. It is established that bacteria in natural habitat has a much higher resistance to in situ irradiation with accelerated electrons when compared to their stability in pure isolated cultures. Thanks to the protective properties of the heterophase environment and the interaction between microbial populations even radiosensitive microorganisms as members of the native microbial communities are able to withstand very high doses of ionizing radiation.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 15
    Publication Date: 2018-08-15
    Description: Geosciences, Vol. 8, Pages 305: Adapting Cultural Heritage to Climate Change Risks: Perspectives of Cultural Heritage Experts in Europe Geosciences doi: 10.3390/geosciences8080305 Authors: Elena Sesana Alexandre S. Gagnon Chiara Bertolin John Hughes Changes in rainfall patterns, humidity, and temperature, as well as greater exposure to severe weather events, has led to the need for adapting cultural heritage to climate change. However, there is limited research accomplished to date on the process of adaptation of cultural heritage to climate change. This paper examines the perceptions of experts involved in the management and preservation of cultural heritage on adaptation to climate change risks. For this purpose, semi-structured interviews were conducted with experts from the UK, Italy, and Norway as well as a participatory workshop with stakeholders. The results indicate that the majority of interviewees believe that adaptation of cultural heritage to climate change is possible. Opportunities for, barriers to, and requirements for adapting cultural heritage to climate change, as perceived by the interviewees, provided a better understanding of what needs to be provided and prioritized for adaptation to take place and in its strategic planning. Knowledge of management methodologies incorporating climate change impacts by the interviewees together with best practice examples in adapting cultural heritage to climate change are also reported. Finally, the interviewees identified the determinant factors for the implementation of climate change adaptation. This paper highlights the need for more research on this topic and the identification and dissemination of practical solutions and tools for the incorporation of climate change adaptation in the preservation and management of cultural heritage.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 16
    Publication Date: 2018-08-22
    Description: Geosciences, Vol. 8, Pages 312: Lake Nyos, a Multirisk and Vulnerability Appraisal Geosciences doi: 10.3390/geosciences8090312 Authors: Mesmin Tchindjang Situated at the northern flank of the Oku Massif, Lake Nyos crater epitomizes landscape features originating from volcanic explosions during the Quaternary. The Cameroon Volcanic Line (CVL), to which it belongs, constitutes the most active volcanic region in Cameroon. In 1986, an outgas explosion occurred from beneath the lake and killed 1746 people in several neighbouring villages. The event influenced a radial area of 25 to 40 km wide, particularly in eastern and western direction. This was mainly due to: (1) the rugged nature of the landscape (fault fields), which enabled the heavier gas to follow valleys framed by faults corridors without affecting elevated areas; and (2) the seasonal dominating western wind direction, which channeled the gas along tectonic corridors and valleys. This paper assesses the geological risk and vulnerability in the Lake Nyos before and after several proposal to mitigate future outgas events. Remotely sensed data, together with GIS tools (topographic maps, aerial photographs), helped to determine and assess lineaments and associated risks. A critical grid combining severity and frequency analysis was used to assess the vulnerability of the local population. There is evidence that along the main fault directions (SW–NE), anthropogenic activities are most intensive and they may play an aggravating role for disasters. This requires the local population’s consciousness-raising. The results also show that population around Lake Nyos still remains vulnerable to volcanic hazards and floods. However, the area has been safe since the last degassing and jet grouting through multiple procedures and actions proposed in the National Contingency Plan, and equally by the relief organization plan (DROP or ORSEC plan) for the Menchum Division. Another issue is that the local population is concerned with the idea of returning to the affected areas in order to stay close to their ancestors or the deceased. Therefore, even after jet grouting and degassing, the problem of risk minimization for local residents remains.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 17
    Publication Date: 2018-08-23
    Description: Geosciences, Vol. 8, Pages 313: Micromorphological and Chemical Features of Soils as Evidence of Bronze Age Ancient Anthropogenic Impact (Late Bronze Age Muradymovo Settlement, Ural Region, Russia) Geosciences doi: 10.3390/geosciences8090313 Authors: Alexandra Golyeva Olga Khokhlova Marina Lebedeva Nickolay Shcherbakov Iia Shuteleva In some cases, the human impact on ancient landscapes has been so profound that local soils still remain significantly affected even after hundreds and thousands of years after ending impact. We studied the Late Bronze Age Muradymovo settlement located in the Urals, Russia, aiming to estimate the consequences of the ancient people’s activity on the environment. Despite the present humid climate, the modern soils inside the cultural layer of the study site contain more than 27% of gypsum at a depth of just 10 cm from the surface, and a microrelief of the study site is typical of a gypsum desert. The nearby background Chernozems are gypsum-free to a depth of 2 m. According to the archaeological data, the ancient people belonged to the ‘Srubno-Alakul’ archaeological culture (1750–1350 years B.C. cal (calibrated years before Christ)) and had a tradition of building their houses from gypsum rocks. At the present time, this area is still unsuitable for human settlement. The properties of modern soils inside the cultural layer of the study site are directly affected by the Late Bronze Age human activities. It has been identified on soil morphology, micromorphology, and chemical properties of soils developed inside the cultural layer of the settlement.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 18
    Publication Date: 2018-08-25
    Description: Geosciences, Vol. 8, Pages 317: Time Series Regression for Forecasting Flood Events in Schenectady, New York Geosciences doi: 10.3390/geosciences8090317 Authors: Thomas A. Plitnick Antonios E. Marsellos Katerina G. Tsakiri Floods typically occur due to ice jams in the winter or extended periods of precipitation in the spring and summer seasons. An increase in the rate of water discharge in the river coincides with a flood event. This research combines the time series decomposition and the time series regression model for the flood prediction in Mohawk River at Schenectady, New York. The time series decomposition has been applied to separate the different frequencies in hydrogeological and climatic data. The time series data have been decomposed into the long-term, seasonal-term, and short-term components using the Kolmogorov-Zurbenko filter. For the application of the time series regression model, we determine the lags of the hydrogeological and climatic variables that provide the maximum performance for the model. The lags applied in the predictor variables of the model have been used for the physical interpretation of the model to strengthen the relationship between the water discharge and the climatic and hydrogeological variables. The overall model accuracy has been increased up to 73%. The results show that using the lags of the variables in the time regression model, and the forecasting accuracy has been increased compared to the raw data by two times.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 19
    Publication Date: 2018-08-25
    Description: Geosciences, Vol. 8, Pages 318: Objective Regolith-Landform Mapping in a Regolith Dominated Terrain to Inform Mineral Exploration Geosciences doi: 10.3390/geosciences8090318 Authors: Alicia S. Caruso Kenneth D. Clarke Caroline J. Tiddy Steven Delean Megan M. Lewis An objective method for generating statistically sound objective regolith-landform maps using widely accessible digital topographic and geophysical data without requiring specific regional knowledge is demonstrated and has application as a first pass tool for mineral exploration in regolith dominated terrains. This method differs from traditional regolith-landform mapping methods in that it is not subject to interpretation and bias of the mapper. This study was undertaken in a location where mineral exploration has occurred for over 20 years and traditional regolith mapping had recently been completed using a standardized subjective methodology. An unsupervised classification was performed using a Digital Elevation Model, Topographic Position Index, and airborne gamma-ray radiometrics as data inputs resulting in 30 classes that were clustered to eight groups representing regolith types. The association between objective and traditional mapping classes was tested using the ‘Mapcurves’ algorithm to determine the ‘Goodness-of-Fit’, resulting in a mean score of 26.4% between methods. This Goodness-of-Fit indicates that this objective map may be used for initial mineral exploration in regolith dominated terrains.
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    Topics: Geosciences
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  • 20
    Publication Date: 2018-08-29
    Description: Geosciences, Vol. 8, Pages 321: Groundwater Characterization by Means of Conservative (δ18O and δ2H) and Non-Conservative (87Sr/86Sr) Isotopic Values: The Classical Karst Region Aquifer Case (Italy–Slovenia) Geosciences doi: 10.3390/geosciences8090321 Authors: Chiara Calligaris Kim Mezga Francesca Federica Slejko Janko Urbanc Luca Zini The study of the different hydrogeological compartments is a prerequisite for understanding and monitoring different fluxes, thereby evaluating the environmental changes in an ecosystem where anthropogenic disturbances are present in order to preserve the most vulnerable groundwaters from contamination and degradation. In many karst domains in the Mediterranean, areas groundwaters and surface waters are a single system, as a result of the features that facilitate the ingression of waters from surface to subsurface. This is also the case for the Classical Karst hydrostructure, which is a carbonate plateau that rises above the northern Adriatic Sea, shared between Italy and Slovenia. The main suppliers to the aquifer are the effective precipitations and the waters from three different rivers: Reka/Timavo, Soča/Isonzo and Vipava/Vipacco. Past and ongoing hydrogeological studies on the area have focused on the connections within the Classical Karst Region aquifer system through the analysis of water caves and springs hydrographs and chemographs. In this paper, the authors present new combined data from major ions, oxygen, hydrogen and strontium stable and radiogenic isotopes which have allowed a more complementary knowledge of the groundwater circulation, provenance and water-rock interactions. All the actions occurred in the framework of the European project HYDROKARST.
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  • 21
    Publication Date: 2018-08-30
    Description: Geosciences, Vol. 8, Pages 325: A Quantitative Comparison of Exoplanet Catalogs Geosciences doi: 10.3390/geosciences8090325 Authors: Dolev Bashi Ravit Helled Shay Zucker In this study, we investigated the differences between four commonly-used exoplanet catalogs (exoplanet.eu; exoplanetarchive.ipac.caltech.edu; openexoplanetcatalogue.com; exoplanets.org) using a Kolmogorov–Smirnov (KS) test. We found a relatively good agreement in terms of the planetary parameters (mass, radius, period) and stellar properties (mass, temperature, metallicity), although a more careful analysis of the overlap and unique parts of each catalog revealed some differences. We quantified the statistical impact of these differences and their potential cause. We concluded that although statistical studies are unlikely to be significantly affected by the choice of catalog, it would be desirable to have one consistent catalog accepted by the general exoplanet community as a base for exoplanet statistics and comparison with theoretical predictions.
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  • 22
    Publication Date: 2018-08-30
    Description: Geosciences, Vol. 8, Pages 322: Review of Potential Risk Factors of Cultural Heritage Sites and Initial Modelling for Adaptation to Climate Change Geosciences doi: 10.3390/geosciences8090322 Authors: Paul Carroll Eeva Aarrevaara There are a range of local weather- and climate-related factors that contribute to the degradation of cultural heritage buildings, structures, and sites over time. Some of these factors are influenced by changes in climate and some of these changes manifest themselves through a speeding up of the rate of degradation. It is the intention of this paper to review this situation with special reference to the Nordic Countries, where typical trends resulting from climate change are shorter winters and increased precipitation all year round. An attempt is made to initially draw up a classification of materials and structures relevant to cultural heritage that are affected, with a proposed numeric scale for the urgency to act. The intention is to provide information on where best to concentrate cultural heritage site preservation resources in the future.
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  • 23
    Publication Date: 2018-08-30
    Description: Geosciences, Vol. 8, Pages 323: Decorrelation of GRACE Time Variable Gravity Field Solutions Using Full Covariance Information Geosciences doi: 10.3390/geosciences8090323 Authors: Alexander Horvath Michael Murböck Roland Pail Martin Horwath In this study the feasibility and performance of time variable decorrelation (VADER) filters derived from covariance information on decadal Gravity Recovery and Climate Experiment (GRACE) time series are investigated. The VADER filter is based on publicly available data that are provided by several GRACE processing centers, and does not need its own Level-2 processing chain. Numerical closed loop simulations, incorporating stochastic and deterministic error budgets, serve as basis for the design of the filter setup, and the resulting filters are subsequently applied for real data processing. The closed loop experiments demonstrate the impact of temporally varying error and signal covariance matrices that are used for the design of decorrelation filters. The results indicate an average reduction of cumulative geoid height errors of 15% using time-variable instead of static decorrelation. Based on the simulation experience, a real data filtering procedure is designed and set up. It is applied to the ITSG-Grace2014 time variable gravity field time series with its associated full monthly covariance matrices. To assess the validity of the approach, linear mass trend estimates for the Antarctic Peninsula are computed using VADER filters and compared to previous estimates from both, GRACE and other mass balance estimation techniques. The mass change results obtained show very good agreement with other estimates and are robust against variations of the filter strength. The DDK decorrelation filter serves as main benchmark for the assessment of the VADER filter. For comparable filter strengths the VADER filters achieve a better de-striping and deliver smaller formal errors than static filters like the DDK.
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  • 24
    Publication Date: 2018-08-30
    Description: Geosciences, Vol. 8, Pages 324: A Multi-Scale Conceptual Model of Flood-Tide Delta Morphodynamics in Micro-Tidal Estuaries Geosciences doi: 10.3390/geosciences8090324 Authors: Timothy P Austin Ana Vila-Concejo Andrew D Short Roshanka Ranasinghe Wave and tide induced sediment transport pathways and rates govern the morphological evolution of estuarine systems. An understanding of the morphodynamics of these systems is required to maintain their commercial, biological and recreational value. The morphodynamics of Port Stephens estuary, a micro-tidal estuary located on a wave dominated southeast coast of Australia were investigated using bathymetric surveys and current velocity data from several locations over the estuary. This provided detailed insight into the rates and direction of movement for the main sedimentary features of the system, and how these features interact with the processes that drive their evolution. We used these findings to develop a conceptual model for estuarine morphodynamics that accounts for fair weather and storm conditions. Our model explains how sediment eroded from the estuarine beaches is trapped by the adjacent flood-tide delta. The model is applicable to fetch-limited estuaries that do not have offshore sources of sediment, where the tidal currents are weak in relation to the incident ocean waves, and that have a wide, stable entrance through which ocean waves can propagate into the estuary. The model is multi-scale in that it encapsulates both short-term and local process, and large scale evolution of an estuary; therefore, it represents a tool that may be used in developing sustainable estuary management strategies.
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  • 25
    Publication Date: 2018-09-01
    Description: Geosciences, Vol. 8, Pages 327: A Comparison of the Dinosaur Communities from the Middle Jurassic of the Cleveland (Yorkshire) and Hebrides (Skye) Basins, Based on Their Ichnites Geosciences doi: 10.3390/geosciences8090327 Authors: Mike Romano Neil Clark Stephen Brusatte Despite the Hebrides and Cleveland basins being geographically close, research has not previously been carried out to determine faunal similarities and assess the possibility of links between the dinosaur populations. The palaeogeography of both areas during the Middle Jurassic shows that there were no elevated landmasses being eroded to produce conglomeratic material in the basins at that time. The low-lying landscape and connected shorelines may have provided connectivity between the two dinosaur populations. The dinosaur fauna of the Hebrides and Cleveland basins has been assessed based primarily on the abundant ichnites found in both areas as well as their skeletal remains. In the two basins, the dinosaur faunas are very similar, consisting of non-neosauropod eusauropods, a possible basal titanosauriform, large and small theropods and ornithopods and europodan thyreophorans. The main difference in the faunas is in the sizes. In the Cleveland Basin, the ichnites suggest that there were medium and large theropods alongside small to medium sized ornithopods, whereas, in the Hebrides Basin, the theropods were from small to large and the ornithopods were medium to large. It is suggested that migrations could have taken place between the two areas during the Middle Jurassic. A tentative food chain from the herbivorous dinosaurs to the top predators can be inferred from the footprints.
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  • 26
    Publication Date: 2018-09-05
    Description: Geosciences, Vol. 8, Pages 332: The Influence of Crude Oil on Mechanistic Detachment Rate Parameters Geosciences doi: 10.3390/geosciences8090332 Authors: Manar B. Hasan Abdul-Sahib T. Al-Madhhachi Iraqi soil contamination greatly influenced soil detachment. Previous researchers have not been able to predict the influence of crude oil soil contamination on either the mechanistic dimensional detachment parameter b0 or the threshold parameter b1 of the mechanistic detachment model (Wilson model). The aims of this research were (1) to investigate the influence of crude oil on deriving Wilson model parameters, b0 and b1, with two setups at different scales and different soil moisture contents and (2) to predict b0 and b1 in crude oil contaminated dry soils with varying levels of contamination. The “mini” JET apparatus was implemented under laboratory conditions for soil specimens packed at both a small (standard mold) and a large (in-situ soil box) scale. The results showed an inverse correlation between b0 and water content for clean soil. No correlation between b0 and soil moisture content was observed for contaminated soils. There was a huge reduction in the b0 value as the contamination time increased compared to the clean soil. This was related to the role crude oil plays in soil stabilization. Crude oil contamination significantly increased lead contamination level while slightly increasing the pH and total organic carbon. The influence of crude oil on mechanistic soil detachment can be predicted with a priori JET experiments on soils without crude oil based on crude oil parameters.
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  • 27
    Publication Date: 2018-09-12
    Description: Geosciences, Vol. 8, Pages 342: Waste Concrete Valorization; Aggregates and Mineral Carbonation Feedstock Production Geosciences doi: 10.3390/geosciences8090342 Authors: Louis-César Pasquier Nassima Kemache Julien Mocellin Jean-François Blais Guy Mercier Concrete is a major constituent of our world. Its contributes to building society but is also an important contributor to the global CO2 emissions. The combination of waste concrete recycling and greenhouse gas abatement is obviously an interesting approach. Mineral carbonation is the methodology that allows the use of calcium oxide within the concrete and transform it into carbonates with the CO2. Following previous results, carbonation experiments were performed using concrete paste extracted from a waste concrete sample after aggregate separation. The latter was performed after crushing and attrition followed by sieving to obtain three fractions. The coarser one composed of aggregates, the second of sand and the last, a fine powder of waste concrete paste (MCF). The MCF is then used in carbonation experiments in an 18.7 L stirred reactor with a diluted source of CO2 following previously optimized conditions. Different S/L ratios were experimented. The results show that 110 kg of CO2 can be stored per ton of MCF obtained after separation. Using the mass balance obtained from the experiments, an economic evaluation was performed on both aggregate separation and carbonation. While the first step can be profitable, using the MCF as a material for industrial flue gas abatement is less evident, both on the applicability and the feasibility.
    Electronic ISSN: 2076-3263
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  • 28
    Publication Date: 2018-09-09
    Description: Geosciences, Vol. 8, Pages 339: δ13C and δ18O Stable Isotope Analysis Applied to Detect Technological Variations and Weathering Processes of Ancient Lime and Hydraulic Mortars Geosciences doi: 10.3390/geosciences8090339 Authors: Elissavet Dotsika Dafni Kyropoulou Vassilios Christaras Georgios Diamantopoulos Samples of mortars were collected from lime and hydraulic mortars affected by environmental degradation. A total of 63 samples were obtained from Hellenistic, Late Roman and Byzantine historic constructions located at Kavala, Drama and Makrygialos in North Greece. Samples were collected in sections from the surface up to 6 cm deep using a drill-core material. The first sample was collected from the external layer, while the internal samples were collected each 1cm beeper from the previous, in order to monitor the moisture ingress. Isotopic data will make it possible to create an ideal Hellenistic and Byzantine mortar layer and to provide weathering gradients. The isotopic values comprise a range of δ13C and δ18O values from −17.1‰ to 1.2‰ and −25.9‰ to −2‰, respectively. The weathering process of Hellenistic and Byzantine are expressed, by the regression lines δ18Ocalcite matrix = 0.6 × δ13Ccalcite matrix − 1.9 and δ18Ocalcite matrix = 0.6 × δ13Ccalcite matrix − 2.0 for hydraulic and Lime mortars respectively. Pronounced isotopic shift to heavy or light δ13C and δ18O in the carbonate matrix was attributed to the primary source of CO2 (atmospheric versus biogenic) and H2O (evaporation of local primary water), in residual limestone and in secondary processes such as recrystallization of calcite with pore water and salts attack. Exogenic processes related to biological growth are responsible for further alterations of δ18O and δ13C in lime mortars. This study indicated that stable isotope analysis is an excellent tool to fingerprint the origin of carbonate, the environmental setting conditions of mortar, origin of CO2 and water during calcite formation and to determine the weathering depth and the potential secondary degradation mechanisms.
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  • 29
    Publication Date: 2018-09-09
    Description: Geosciences, Vol. 8, Pages 338: Assessing the Validity of Negative High Field Strength-Element Anomalies as a Proxy for Archaean Subduction: Evidence from the Ben Strome Complex, NW Scotland Geosciences doi: 10.3390/geosciences8090338 Authors: George L. Guice Iain McDonald Hannah S. R. Hughes Denis M. Schlatter Kathryn M. Goodenough John M. MacDonald John W. Faithfull The relative depletion of high field strength elements (HFSE), such as Nb, Ta and Ti, on normalised trace-element plots is a geochemical proxy routinely used to fingerprint magmatic processes linked to Phanerozoic subduction. This proxy has increasingly been applied to ultramafic-mafic units in Archaean cratons, but as these assemblages have commonly been affected by high-grade metamorphism and hydrothermal alteration/metasomatism, the likelihood of element mobility is high relative to Phanerozoic examples. To assess the validity of HFSE anomalies as a reliable proxy for Archaean subduction, we here investigate their origin in ultramafic rocks from the Ben Strome Complex, which is a 7 km2 ultramafic-mafic complex in the Lewisian Gneiss Complex of NW Scotland. Recently interpreted as a deformed layered intrusion, the Ben Strome Complex has been subject to multiple phases of high-grade metamorphism, including separate granulite- and amphibolite-facies deformation events. Additional to bulk-rock geochemistry, we present detailed petrography, and major- and trace-element mineral chemistry for 35 ultramafic samples, of which 15 display negative HFSE anomalies. Our data indicate that the magnitude of HFSE anomalies in the Ben Strome Complex are correlated with light rare earth-element (LREE) enrichment likely generated during interaction with H2O and CO2-rich hydrothermal fluids associated with amphibolitisation, rather than primary magmatic (subduction-related) processes. Consequently, we consider bulk-rock HFSE anomalies alone to be an unreliable proxy for Archaean subduction in Archaean terranes that have experienced multiple phases of high-grade metamorphism, with a comprehensive assessment of element mobility and petrography a minimum requirement prior to assigning geodynamic interpretations to bulk-rock geochemical data.
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  • 30
    Publication Date: 2018-09-09
    Description: Geosciences, Vol. 8, Pages 337: Paleo-Drainage Network, Morphotectonics, and Fluvial Terraces: Clues from the Verde Stream in the Middle Sangro River (Central Italy) Geosciences doi: 10.3390/geosciences8090337 Authors: Enrico Miccadei Cristiano Carabella Giorgio Paglia Tommaso Piacentini This work analyzes the role of paleo-drainage network, morphotectonics, and surface processes in landscape evolution in a sector of the transition zone between the chain and the piedmont area of Central Apennines. Particularly, it focuses on the Verde Stream, a tributary of the middle Sangro River valley, which flows in the southeastern Abruzzo area at the boundary with the Molise region. The Verde Stream was investigated through a drainage basin scale geomorphological analysis incorporating the morphometry of the orography and hydrography, structural geomorphological field mapping, and the investigation of morphological field evidence of tectonics with their statistical azimuthal distributions. The local data obtained were compared with the analysis of the middle Sangro River valley and the tectonic features of the Abruzzo–Molise area. This approach led us to also provide relevant clues about the definition of the role of karst features and paleo-landscapes in the general setting of the study area and to identify the impact of active tectonics, confirmed by recent and active seismicity. In conclusion, the paper contributes to defining the main stages of the geomorphological evolution of this area, driven by uplift and local tectonics and due to a combination of fluvial, karst, and landslide processes.
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  • 31
    Publication Date: 2018-09-11
    Description: Geosciences, Vol. 8, Pages 341: Stability of Individuals during Urban Inundations: What Should We Learn from Field Observations? Geosciences doi: 10.3390/geosciences8090341 Authors: Hubert Chanson Richard Brown The flooding of urbanized areas constitutes a major hazard to populations and infrastructure. Flood flows during urban inundations have been studied only recently and the real-life impact of fluid flows on individuals is not well understood. The stability of individuals in floodwaters is re-assessed based upon the re-analysis of detailed field measurements during a major flood event. The results emphasized that hydrodynamic instabilities, linked to local topographic effects and debris, constitute major real-world hazards. A comparison between a number of flow conditions deemed unsafe for individuals, along with guidelines, suggests that many recommendations are over-optimistic and unsafe in real floodwaters and natural disasters. A series of more conservative guidelines is proposed, particularity relevant to flood events.
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  • 32
    Publication Date: 2018-09-18
    Description: Geosciences, Vol. 8, Pages 352: Tracking the Serpentinite Feet of the Mediterranean Salt Giant Geosciences doi: 10.3390/geosciences8090352 Authors: Vittorio Scribano Serafina Carbone Fabio Carmelo Manuella Interpretation of seismic profiles and results of scientific drillings in the Mediterranean subseafloor provided indication of gigantic salt deposits which rarely crop out on land, such as in Sicily. The salt giants were ascribed to the desiccation, driven by the solar energy, of the entire basin. Nevertheless, the evaporite model hardly explains deep-sea salt deposits. This paper considers a different hypothesis suggesting that seawater reached NaCl saturation during serpentinization of ultramafic rocks. Solid salts and brine pockets were buried within the serpentinite bodies being later (e.g., in the Messinian) released, due to serpentinite breakdown, and discharged at seafloor as hydrothermal heavy brines. Therefore, sea-bottom layers of brine at gypsum and halite saturation were formed. The model is applicable to the Mediterranean area since geophysical data revealed relicts of an aged (hence serpentinized) oceanic lithosphere, of Tethyan affinity, both in its western “Atlantic” extension (Gulf of Cádiz) and in eastern basins, and xenoliths from Hyblean diatremes (Sicily) provided evidence of buried serpentinites in the central area. In addition, the buoyant behavior of muddled serpentinite and salts (and hydrocarbons) gave rise to many composite diapirs throughout the Mediterranean area. Thus, the Mediterranean “salt giant” consists of several independent geobodies of serpentinite and salts.
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  • 33
    Publication Date: 2018-09-20
    Description: Geosciences, Vol. 8, Pages 354: Geological Model of a Storage Complex for a CO2 Storage Operation in a Naturally-Fractured Carbonate Formation Geosciences doi: 10.3390/geosciences8090354 Authors: Yann Le Gallo José Carlos de Dios Investigation into geological storage of CO2 is underway at Hontomín (Spain). The storage reservoir is a deep saline aquifer formed by naturally fractured carbonates with low matrix permeability. Understanding the processes that are involved in CO2 migration within these formations is key to ensure safe operation and reliable plume prediction. A geological model encompassing the whole storage complex was established based upon newly-drilled and legacy wells. The matrix characteristics were mainly obtained from the newly drilled wells with a complete suite of log acquisitions, laboratory works and hydraulic tests. The model major improvement is the integration of the natural fractures. Following a methodology that was developed for naturally fractured hydrocarbon reservoirs, the advanced characterization workflow identified the main sets of fractures and their main characteristics, such as apertures, orientations, and dips. Two main sets of fracture are identified based upon their mean orientation: North-South and East-West with different fracture density for each the facies. The flow capacity of the fracture sets are calibrated on interpreted injection tests by matching their permeability and aperture at the Discrete Fracture Network scale and are subsequently upscaled to the geological model scale. A key new feature of the model is estimated permeability anisotropy induced by the fracture sets.
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  • 34
    Publication Date: 2018-09-22
    Description: Geosciences, Vol. 8, Pages 358: Prediction of Holocene Mercury Accumulation Trends by Combining Palynological and Geochemical Records of Lake Sediments (Black Forest, Germany) Geosciences doi: 10.3390/geosciences8100358 Authors: Martin Schütze Gegeensuvd Tserendorj Marta Pérez-Rodríguez Manfred Rösch Harald Biester Forest vegetation plays a key role in the cycling of mercury (Hg) and organic matter (OM) in terrestrial ecosystems. Litterfall has been indicated as the major transport vector of atmospheric Hg to forest soils, which is eventually transported and stored in the sediments of forest lakes. Hence, it is important to understand how changes in forest vegetation affect Hg in soil and its biogeochemical cycling in lake systems. We investigated the pollen records and the geochemical compositions of sediments from two lakes (Schurmsee and Glaswaldsee) in the Black Forest (Germany) to evaluate whether long-term shifts in forest vegetation induced by climate or land use influenced Hg accumulation in the lakes. We were particularly interested to determine whether coniferous forests were associated with a larger export of Hg to aquatic systems than deciduous forests. Principal components analysis followed by principal component regression enabled us to describe the evolution of the weight of the latent processes determining the accumulation of Hg over time. Our results emphasize that the in-lake uptake of Hg during warm climate periods, soil erosion after deforestation and emissions from mining and other human activities triggered changes in Hg accumulation during the Holocene stronger than the changes caused by forest vegetation alone.
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  • 35
    Publication Date: 2018-09-23
    Description: Geosciences, Vol. 8, Pages 359: Coupled Model of Bank Erosion and Meander Evolution for Cohesive Riverbanks Geosciences doi: 10.3390/geosciences8100359 Authors: Kattia Rubi Arnez Ferrel Supapap Patsinghasanee Ichiro Kimura Yasuyuki Shimizu In this paper, a physics-based model that couples a bank erosion model with a meander evolution model is developed and evaluated. The physics-based bank erosion model considers the cantilever failure mechanism with slump blocks and decomposition effects. Moreover, bank accretion was considered using critical values of time required for landing, shear stresses and water depths. Two cases were tested. The first case consists of a hypothetical small-scale channel with cohesive riverbanks. Cross sections in the straight and curved part of the channel were compared to evaluate the curvature effect. Furthermore, the effect of the bank strength in the plan shape of the channel was tested in this case. The results show that the curvature increases the erosion rate in the outer bank and changes the cross-sectional profile by narrowing and widening the channel width. The plan shape of the channel changed as the bank strength was increased. In the second case, the model is compared with the River meander migration software (RVR meander) and the advantages and limitations of the model are discussed in terms of meander migration plan form and bank erosion processes. The results showed that the presented model is capable of simulating asymmetric bends.
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  • 36
    Publication Date: 2018-09-21
    Description: Geosciences, Vol. 8, Pages 356: Suitability of Boulder Marl and Marsh Clay as Sealing Substrates for Landfill Capping Systems—A Practical Comparison Geosciences doi: 10.3390/geosciences8100356 Authors: Steffen Beck-Broichsitter Horst H. Gerke Rainer Horn The effects of compaction on soil shrinkage behavior need to be considered for engineering long-term durable mineral liners of landfill capping systems. For this purpose, a new three-dimensional laser scanning device was coupled with a mathematical-empirical model to simultaneously determine the shrinkage behavior of a boulder marl (bm) and a marsh clay (mc). Therefore, both materials were precompacted in 200 soil cores (100 cm3) on the basis of the Proctor test results with five different degrees of compaction (bm1-bm5; mc1-mc5). Thus, the shrinkage behavior, intensity, and tendency were determined during a standardized drying experiment. The volume shrinkage index was used to describe the pore size dependent shrinkage tendency and was classified as high to very high (11.3–17.7%) for the marsh clay and medium (5.3–9.2%) for the boulder marl. Additionally, only the boulder marl (bm2), compacted up to 88% of Proctor density, could be installed as landfill bottom liner in drier locations if the local matric potentials did not exceed the previously highest observed drying range (i.e. values below −300 hPa), to avoid crack formation and generation.
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  • 37
    Publication Date: 2018-09-21
    Description: Geosciences, Vol. 8, Pages 357: Using a Multi-Proxy Approach to Detect and Date a Buried part of the Hellenistic City Wall of Ainos (NW Turkey) Geosciences doi: 10.3390/geosciences8100357 Authors: Martin Seeliger Anna Pint Peter Frenzel Paula Weisenseel Ercan Erkul Dennis Wilken Tina Wunderlich Sait Başaran Heike Bücherl Marina Herbrecht Wolfgang Rabbel Thomas Schmidts Nina Szemkus Helmut Brückner Throughout mankind’s history, the need to secure and protect the home settlement was an essential one. This holds especially true for the city of Ainos (modern Enez) in Turkish Thrace. Due to its continuous settlement history since the 7th/6th century BC, several different types of city walls were built—sometimes even on top of each other—several of which have been preserved over time. To decipher the construction style, the course and the age of a buried city wall segment in the southern part of the former city, a geoscientific multi-proxy approach including magnetic gradiometer (MG) and electrical resistivity tomography (ERT) measurements in combination with granulometrical, sedimentological and microfaunistical investigations on sediment cores was applied. We were able to (1) present reasonable arguments for its Hellenistic age; (2) reveal the course of this wall segment and extrapolate it further north into a less studied area; and (3) demonstrate that in this near-coastal area, the former swampy terrain had been consolidated for constructing the wall. Our multi-proxy approach serves as a valuable example for investigating buried structures in archaeological contexts, avoiding a less-economical, time-consuming, or even forbidden excavation.
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  • 38
    Publication Date: 2018-09-21
    Description: Geosciences, Vol. 8, Pages 355: Recession and Ice Surface Elevation Changes of Baranowski Glacier and Its Impact on Proglacial Relief (King George Island, West Antarctica) Geosciences doi: 10.3390/geosciences8100355 Authors: Joanna Sziło Robert Józef Bialik Glacial forefields areas are dynamic landscapes, and due to the glacier frontal position changes, they are sensitive to climatic fluctuations. The results of the analysis of aerial photos, satellite imagery, archival maps, and terrestrial laser scanning surveys are presented. These investigations reveal that the ice surface decreased during the period 1989–2001, when almost the entire current forefield was already uncovered. Moreover, it is shown that, since 1969, there has been a relationship between the changes in air temperature and the changes of the annual front position rate of Baranowski Glacier. Specifically, the results demonstrate that during the cooling observed for the Antarctic Peninsula Regions since 2000, there is a deceleration of the recession rate and ice surface elevation changes of Baranowski Glacier. It is also shown that the fluctuation of the areal extent of the glacier as well as ice surface elevation changes are closely associated with proglacial relief. Moreover, it is shown that the difference in the retreat of the northern and southern tongue of the glacier can be explained by the presence of relatively warm water in the shallow bay, which can enhance the melting process of the northern part. In addition, existence of long flutes and crevasse fill ridges on the analyzed forefield of Baranowski Glacier suggest that the former episodes of its surge, which could happen at least in the northern part of the forefield and middle part of the southern forefield of the glacier.
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  • 39
    Publication Date: 2018-08-10
    Description: Geosciences, Vol. 8, Pages 299: Analysis by UAV Digital Photogrammetry of Folds and Related Fractures in the Monte Antola Flysch Formation (Ponte Organasco, Italy) Geosciences doi: 10.3390/geosciences8080299 Authors: Niccolò Menegoni Claudia Meisina Cesare Perotti Matteo Crozi The deformation structures (folds and fractures) affecting Monte Antola flysch formation in the area of Ponte Organasco (Northern Apennines-Italy) were analyzed by Unmanned Aerial Vehicle Digital Photogrammetry (UAVDP). This technique allowed the realization of Digital Outcrop Models (DOMs) interpreted in a stereoscopic environment by collecting a large number of digital structural measures (strata, fractures and successively fold axes and axial planes). In particular, by UAVDP was possible to analyze the relationships between folds and fractures all along the study structures. The structural analysis revealed the presence of a series of NE-vergent folds characterized by a typical Apenninic trend and affected by four main sets of fractures. Fractures are always sub-orthogonal to the bedding, maintains constant angular relationships with the bedding and seems linked to the folding deformation. The study shows that the UAVDP technique can overcome the main limitations of field structural analysis such as the scarce presence and the inaccessibility (total or partial) of rock outcrops and allows for acquiring images of rock outcrops at a detailed scale from user-inaccessible positions and different points of view and analyze inaccessible parts of outcrops.
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  • 40
    Publication Date: 2018-08-11
    Description: Geosciences, Vol. 8, Pages 301: Distribution of Rare Earth Elements in Sediments of the Marine Lake Mir (Dugi Otok, Croatia) Geosciences doi: 10.3390/geosciences8080301 Authors: Željka Fiket Marina Mlakar Goran Kniewald The Lake Mir represents a small, isolated, and shallow marine lake situated in the south-eastern part of the Dugi otok Island, in a karstic landscape of the eastern Adriatic coast. The surrounding karstic background, with occasional occurrences of red soil, characterizes the sediments in the lake as coarse grained and carbonate rich. Previous studies suggested the prevailing influence of the lake bathymetry, that is, the proportion of carbonates and grain size characteristics of the sediments, on the variability of the element composition of the lake sediments. To confirm previous assumptions and obtain a better understanding of the factors influencing sediment composition of this marine lake, the distribution of rare earth elements in sediments of the Lake Mir and the nearby Telašćica Bay, as well as surrounding soils, was investigated. In the lake sediments, the sum of rare earth elements, including Y (hereinafter referred as ΣREY), ranged from 10.6 mg kg−1 to 25.3 mg kg−1; in the Telašćica Bay sediments, ΣREY were higher compared to the lake and ranged from 56.4 mg kg−1 to 85.2 mg kg−1, while the highest ΣREY, from 83.3 mg kg−1 to 227 mg kg−1, were observed in soils surrounding the lake. Despite the difference in the levels of the rare earth elements, the REY normalized patterns and associated fractionation parameters (ΣLREE/ΣHREE, (La/Yb)N, and (Nd/Yb)N) showed similarities between the lake sediments and the surrounding soils, confirming a significant influence of local lithology on the lake composition. The results of the statistical analysis, on the other hand, suggest the contribution of both the carbonate (e.g., calcite) and non-carbonate minerals (i.e., alumosilicates and Al–Fe-hydroxides) on the total REY content in the lake sediments.
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  • 41
    Publication Date: 2018-08-11
    Description: Geosciences, Vol. 8, Pages 300: Improving Flood Maps in Ungauged Fluvial Basins with Dendrogeomorphological Data. An Example from the Caldera de Taburiente National Park (Canary Islands, Spain) Geosciences doi: 10.3390/geosciences8080300 Authors: Julio Garrote Andrés Díez-Herrero Mar Génova José M. Bodoque María A. Perucha Pablo L. Mayer Flash floods represent one of the more usual natural hazards in mountain basins, and, combined with the lack of reliable flow data and the recreational use of the drainage basin by tourists and hikers, there is a significant risk of catastrophe. Here, we present a dendro-geomorphological reconstruction of a past flash flood event in the Caldera de Taburiente N.P. (Canary Islands, Spain), an ungauged drainage basin in the SW side of the volcanic island of La Palma. We couple two-dimensional hydraulic modelling in a highly-resolved topographic environment (LiDAR data) with (1) peak flow data for various Tyear return periods from an uncalibrated hydrological model and (2) a data set of scars on trees, to investigate the magnitude of a 1997 dated flash-flood. From the results, flood hazards and associated risks would be clearly underestimated by using only the unique available hydrological data (a rainfall gauge station downstream of the study area). Hydraulic models using scars data show a higher flood hazard scenario, improving the flood hazard map by using all available flood evidence. Moreover, all this will allow for better implementation of appropriate adaptation policies by National Park managers, and therefore the mitigation of future disasters.
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  • 42
    Publication Date: 2018-08-13
    Description: Geosciences, Vol. 8, Pages 303: The Relationship between InSAR Coseismic Deformation and Earthquake-Induced Landslides Associated with the 2017 Mw 3.9 Ischia (Italy) Earthquake Geosciences doi: 10.3390/geosciences8080303 Authors: Matteo Albano Michele Saroli Antonio Montuori Christian Bignami Cristiano Tolomei Marco Polcari Giuseppe Pezzo Marco Moro Simone Atzori Salvatore Stramondo Stefano Salvi We investigated the contribution of earthquake-induced surface movements to the ground displacements detected through Interferometric Synthetic Aperture Radar (InSAR) data, after the Mw 3.9 Ischia earthquake on 21 August 2017. A permanent displacement approach, based on the limit equilibrium method, allowed estimation of the spatial extent of the earthquake-induced landslides and the associated probability of failure. The proposed procedure identified critical areas potentially affected by slope movements partially overlapping the coseismic ground displacement retrieved by InSAR data. Therefore, the observed ground displacement field is the combination of both fault slip and surficial sliding caused by the seismic shaking. These findings highlight the need to perform preliminary calculations to account for the non-tectonic contributions to ground displacements before any estimation of the earthquake source geometry and kinematics. Such information is fundamental to avoid both the incorrect definition of the source geometry and the possible overestimation of the coseismic slip over the causative fault. Moreover, knowledge of the areas potentially affected by slope movements could contribute to better management of a seismic emergency, especially in areas exposed to high seismic and hydrogeological risks.
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  • 43
    Publication Date: 2018-08-15
    Description: Geosciences, Vol. 8, Pages 304: Fluvial Geomorphology, Root Distribution, and Tensile Strength of the Invasive Giant Reed, Arundo Donax and Its Role on Stream Bank Stability in the Santa Clara River, Southern California Geosciences doi: 10.3390/geosciences8080304 Authors: Jiana E. Stover Edward A. Keller Tom L. Dudley Eddy J. Langendoen Arundo donax (giant reed) is a large, perennial grass that invades semi-arid riparian systems where it competes with native vegetation and modifies channel geomorphology. For the Santa Clara River, CA, changes in channel width and intensity of braiding over several decades are linked in part to high flow events that remove A. donax. Nevertheless, the area of A. donax at the two study sites increased fivefold over a period of 28 years at one site and fourfold over 15 years at the second site. Effects of A. donax on bank stability are compared to those of a common native riparian tree—Salix laevigata (red willow)—at two sites on the banks and floodplain of the Santa Clara River. There is a significant difference of root density of A. donax compared to S. laevigata and the latter has a higher number of roots per unit area at nearly all depths of the soil profile. Tensile root strength for S. laevigata (for roots of 1–6 mm in diameter) is about five times stronger than for A. donax and adds twice the apparent cohesion to weakly cohesive bank materials than does A. donax (8.6 kPa compared to 3.3 kPa, respectively). Modeling of bank stability for banks of variable height suggests that S. laevigata, as compared to A. donax, increases the factor of safety (FS) by ~60% for banks 1 m high, ~55% for banks 2 m high and ~40% for banks 3 m high. For 3 m high banks, the FS for banks with A. donax is <1. This has geomorphic significance because, in the case of A. donax growing near the water line of alluvial banks, the upper 10–20 cm has a hard, resistant near-surface layer overlying more erodible banks just below the near-surface rhizomal layer. Such banks may be easily undercut during high flow events, resulting in overhanging blocks of soil and A. donax that slump and collapse into the active channel, facilitating lateral bank erosion. Therefore, there is a decrease in the lateral stability of channels if the mixed riparian forest is converted to dominance by A. donax.
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  • 44
    Publication Date: 2018-08-21
    Description: Geosciences, Vol. 8, Pages 307: Prospecting Glacial Ages and Paleoclimatic Reconstructions Northeastward of Nevado Coropuna (16° S, 73° W, 6377 m), Arid Tropical Andes Geosciences doi: 10.3390/geosciences8080307 Authors: Jose Úbeda Martí Bonshoms Joshua Iparraguirre Lucía Sáez Ramón de la Fuente Lila Janssen Ronald Concha Pool Vásquez Pablo Masías This work investigates the timing, paleoclimatic framework and inter-hemispheric teleconnections inferred from the glaciers last maximum extension and the deglaciation onset in the Arid Tropical Andes. A study area was selected to the northeastward of the Nevado Coropuna, the volcano currently covered by the largest tropical glacier on Earth. The current glacier extent, the moraines deposited in the past and paleoglaciers at their maximum extension have been mapped. The present and past Equilibrium Line Altitudes (ELA and paleoELA) have been reconstructed and the chlorine-36 ages have been calculated, for preliminary absolute dating of glacial and volcanic processes. The paleoELA depression, the thermometers installed in the study area and the accumulation data previously published allowed development of paleotemperature and paleoprecipitation models. The Coropuna glaciers were in maximum extension (or glacial standstill) ~20–12 ka ago (and maybe earlier). This last maximum extension was contemporary to the Heinrich 2–1 and Younger Dryas events and the Tauca and Coipasa paleolake transgressions on Bolivian Altiplano. The maximum paleoELA depression (991 m) shows a colder (−6.4 °C) and moister climate with precipitation ×1.2–×2.8 higher than the present. The deglaciation onset in the Arid Tropical Andes was 15–11 ka ago, earlier in the most southern, arid, and low mountains and later in the northernmost, less arid, and higher mountains.
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  • 45
    Publication Date: 2018-08-24
    Description: Geosciences, Vol. 8, Pages 314: The Critical Role of the Boundary Layer Thickness for the Initiation of Aeolian Sediment Transport Geosciences doi: 10.3390/geosciences8090314 Authors: Thomas Pähtz Manousos Valyrakis Xiao-Hu Zhao Zhen-Shan Li Here, we propose a conceptual framework of Aeolian sediment transport initiation that includes the role of turbulence. Upon increasing the wind shear stress τ above a threshold value τ t ′ , particles resting at the bed surface begin to rock in their pockets because the largest turbulent fluctuations of the instantaneous wind velocity above its mean value u ¯ induce fluid torques that exceed resisting torques. Upon a slight further increase of τ , rocking turns into a rolling regime (i.e., rolling threshold τ t ≃ τ t ′ ) provided that the ratio between the integral time scale T i ∝ δ / u ¯ (where δ is the boundary layer thickness) and the time T e ∝ d / [ ( 1 − 1 / s ) g ] required for entrainment (where d is the particle diameter and s the particle–air–density ratio) is sufficiently large. Rolling then evolves into mean-wind-sustained saltation transport provided that the mean wind is able to compensate energy losses from particle-bed rebounds. However, when T i / T e is too small, the threshold ratio scales as τ t / τ t ′ ∝ T e / T i ∝ s d 2 / δ 2 , consistent with experiments. Because δ / d controls T i / T e and the relative amplitude of turbulent wind velocity fluctuations, we qualitatively predict that Aeolian sediment transport in natural atmospheres can be initiated under weaker (potentially much weaker) winds than in wind tunnels, consistent with indirect observational evidence on Earth and Mars.
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  • 46
    Publication Date: 2018-08-24
    Description: Geosciences, Vol. 8, Pages 315: Impact of Groundtrack Pattern of a Single Pair Mission on the Gravity Recovery Quality Geosciences doi: 10.3390/geosciences8090315 Authors: Siavash Iran-Pour Matthias Weigelt Alireza Amiri-Simkooei Nico Sneeuw For future gravity satellite missions, aliasing of high frequency geophysical signals into the lower frequencies is one of the most challenging obstacles to recovering true gravity signals, i.e., to recover the truth. Several studies have investigated the impact of satellite groundtrack pattern on the quality of gravity recovery. Among those works, the concept of sub-cycle has been discussed as well. However, most of that research has focused on the impact of sampling patterns on global solutions up to a fixed maximum spherical harmonic coefficient, rather than the associated coefficient defined by the Colombo-Nyquist and modified Colombo-Nyquist rules. This work tries to look more closely into the influence of sampling patterns on the gravity recovery quality for global and regional studies when the Colombo-Nyquist and modified Colombo-Nyquist rules apply. For the regional study, the impact of groundtrack patterns of different satellite constellation scenarios are investigated for a hydrological basin in central Africa. The quality of the gravity products are assessed by different metrics, e.g., by spatial covariance representation. The potential meaning of the sub-cycle concept in terms of global and local impacts is also investigated by different repeat-orbit scenarios with even and odd parities. Different solution scenarios in terms of the original and modified Colombo-Nyquist rules will be discussed. The results of our study emphasize the impact of maximum harmonics of the recovery, the influence of sub-cycle on the local gravity recovery and the mission formation impact on the recovery error.
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  • 47
    Publication Date: 2018-08-28
    Description: Geosciences, Vol. 8, Pages 320: A Permanent, Real-Time Monitoring Network for the Volcanoes Mount Scenery and The Quill in the Caribbean Netherlands Geosciences doi: 10.3390/geosciences8090320 Authors: Elske Dalfsen Reinoud Sleeman The stratovolcanoes of Mt. Scenery at Saba and The Quill in St. Eustatius in the Caribbean Netherlands, with a total population of about 5200 people, are part of the active volcanic arc of the Lesser Antilles but lacked a multiparameter volcano and earthquake monitoring system until the beginning of 2018. The permanent seismic network on the islands has been built up since 2006 and was expanded in 2018 with one permanent Global Navigation Satellite System (GNSS) sensor at each volcano and a temperature logger on Saba. We provide technical details of all equipment and the installation procedures, and we show the preliminary results of GNSS data processing. Deploying a remote, permanent network of different sensor types under tropical island conditions and sustaining access to real-time high-quality data to monitor the state of volcanoes is an underappreciated challenge. Despite the problems encountered, we operated the network with an overall availability of 84.5% in the first half of 2018 compared to 70.3% in the years before. The main unresolved problem affecting seismic data quality is related to sudden out-of-balance seismometer mass positions. We provide a complete overview of our monitoring network, the various challenges encountered, and the solutions applied, and we address future plans.
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  • 48
    Publication Date: 2018-09-04
    Description: Geosciences, Vol. 8, Pages 331: Right-Angle Pattern of Minor Fluvial Networks from the Ionian Terraced Belt, Southern Italy: Passive Structural Control or Foreland Bending? Geosciences doi: 10.3390/geosciences8090331 Authors: Dario Gioia Marcello Schiattarella Salvatore Ivo Giano Morphometric analyses of both the topography and drainage network have been carried out in a large sector of the Ionian coastal belt of southern Italy in order to unravel the possible control of Late Quaternary thrust front activity on the evolution of the fluvial net. The study area extends in the southernmost sector of the Bradano Foredeep and is featured by several orders of uplifted marine terraces, ranging in age from Middle Pleistocene to Late Quaternary. The flight of the marine terraces is deeply cut by a trellis-type and regularly spaced minor fluvial network. Morphotectonic investigations based on field survey, photo-aerial interpretation, topographic attributes, morphometric indices, and analysis of longitudinal river profiles suggest a strong control on the drainage network arrangement by a pervasive orthogonal fracture system, produced and preserved into the brittle caprock of the terraces, made by conglomerate. Since a similar pervasive and orthogonal fracture pattern is typically generated by gentle folding of rocks, the development of the Ionian hydrographic networks could be attributed to a general—maybe still active—bending of the foredeep area due to the eastward propagation of blind thrusting of the Apennines orogenic chain.
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  • 49
    Publication Date: 2018-09-04
    Description: Geosciences, Vol. 8, Pages 329: Tailoring Signs to Engage Two Distinct Types of Geotourists to Geological Sites Geosciences doi: 10.3390/geosciences8090329 Authors: Sonja M. Prendivoj Interpretive signs are the silent ambassadors of geosites and serve a diverse audience. The primary aim of this study is to develop signs for geosites targeted at two unique groups of geotourists. A conceptual multidisciplinary geotourist typology is formulated to identify two main classes of geotourists comprising the audience. Latent and archetypal geotourists inhabit various roles at geotourism sites depending on their expectations for the event, affecting the visitor experience via fluid contextual factors. Principally, latent geotourists arrive seeking novel touristic experiences while archetypal geotourists seek knowledge-building opportunities. Because signs represent one fragment of the multi-dimensional visitor experience, an approach that offers a palette of options is advocated. After the unified typology to identify the audience is presented, a multi-layered technique that offers both interpretation and a link to augmented information on signs is suggested. Some best practices in sign design are described and preliminary plans for testing are shared. The author’s overriding goal is to refine the mechanics and format of signs to garner maximum attracting and holding power, ensuring that the message is read and the target outcome is achieved. By providing tools to visitors to geological sites that enable them to create narratives that are compatible with their expectations, we facilitate a multi-dimensional constructive experience that engages everyone.
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  • 50
    Publication Date: 2018-09-04
    Description: Geosciences, Vol. 8, Pages 328: Contrasting Textural and Chemical Signatures of Chromitites in the Mesoarchaean Ulamertoq Peridotite Body, Southern West Greenland Geosciences doi: 10.3390/geosciences8090328 Authors: Juan Miguel Guotana Tomoaki Morishita Ryoko Yamaguchi Ikuya Nishio Akihiro Tamura Kenichiro Tani Yumiko Harigane Kristoffer Szilas D. Graham Pearson Peridotites occur as lensoid bodies within the Mesoarchaean orthogneiss in the Akia terrane of Southern West Greenland. The Ulamertoq peridotite body is the largest of these peridotites hosted within the regional orthogneiss. It consists mainly of olivine, orthopyroxene, and amphibole-rich ultramafic rocks exhibiting metamorphic textural and chemical features. Chromitite layers from different localities in Ulamertoq show contrasting characteristics. In one locality, zoned chromites are hosted in orthopyroxene-amphibole peridotites. Compositional zonation in chromites is evident with decreasing Cr and Fe content from core to rim, while Al and Mg increase. Homogeneous chromites from another locality are fairly uniform and Fe-rich. The mineral chemistry of the major and accessory phases shows metamorphic signatures. Inferred temperature conditions suggest that the zoned chromites, homogeneous chromites, and their hosts are equilibrated at different metamorphic conditions. In this paper, various mechanisms during the cumulus to subsolidus stages are explored in order to understand the origin of the two contrasting types of chromites.
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  • 51
    Publication Date: 2018-09-12
    Description: Geosciences, Vol. 8, Pages 344: Assessment of Specific Yield in Karstified Fractured Rock through the Water-Budget Method Geosciences doi: 10.3390/geosciences8090344 Authors: Marco Delle Rose Corrado Fidelibus Paolo Martano In this note, the Water Budget Method (WBM) is applied to estimate local values of the specific yield of the deep karst aquifer of Salento peninsula. A selection in a period of two years of relevant short precipitation events has been considered and the related localized recharges have been compared to the water table fluctuations measured at two selected wells. The recharge amounts have been corrected by using data of evapotranspiration and soil water storage available from a micrometeorological base. The results are very similar for both the wells and more consistent when the corrections are applied. A discussion involving frequency and apertures of the fractures in the rock mass of the aquifer suggests the effect of the karst dissolution to be dominant in determining these values of the specific yield.
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  • 52
    Publication Date: 2018-09-12
    Description: Geosciences, Vol. 8, Pages 343: A Study on Variation in Channel Width and Braiding Intensity of the Brahmaputra River in Assam, India Geosciences doi: 10.3390/geosciences8090343 Authors: Jogendra Nath Sarma Shukla Acharjee The Brahmaputra River flows through Assam, India, for about 670 km along an alluvial valley as a wide braided river. The width of the river varies with time along its course. The braiding intensity of this river is estimated using the braiding index (BI) of Brice (1964), which also changes with space and time along the course of the river. Temporal changes of both width and BI have been studied using topographic maps of 1912–1928 and 1963–1975, and dry season satellite data of 1996, 2000, 2007 and 2009. The mean widths of the Brahmaputra River channel in Assam during 1912–1928, 1963–1975, 1996, 2000, 2007 and 2009 were 5949 m, 7455 m, 7505 m, 8008 m, 8308 m and 9012 m, respectively, confirming an overall increase in width with time. Both the width and variation of width are lowest in four short narrower segments of the river. Three of these segments represent hard points comprising gneissic rock, and one segment is on alluvium comprising cohesive clay. The increase in width is correlated to enormous sediment load produced by the great Assam earthquake of 1950 and large-scale deforestation in the Himalayas. The mean BIs for the Brahmaputra for 1963–1975, 1996, 2000, 2007 and 2009 were 8.59, 8.43, 6.67, 6.58 and 7.70, respectively, indicating in general a decreasing trend up to 2007. The BI showed low variation at the four narrow segments where there is also a minimum variation of the channel width. The BI has increased significantly in the upstream part of the river. Very high fluctuation of discharge (17,000 m 3 / s − 1 in 24 h) and high sediment loads of the Brahmaputra (daily mean sediment discharge of 2.0 million tonnes during monsoon), erodible alluvial banks and high width/depth ratios are the main causes of development of braiding. The interrelationship between channel width and BI of the Brahmaputra shows a positive correlation, indicating an increase in BI with increasing channel width.
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  • 53
    Publication Date: 2018-09-13
    Description: Geosciences, Vol. 8, Pages 345: Age and Origin of the Mesoproterozoic Iron Oxide-Apatite Mineralization, Cheever Mine, Eastern Adirondacks, NY Geosciences doi: 10.3390/geosciences8090345 Authors: Jeffrey R. Chiarenzelli Marian V. Lupulescu Sean P. Regan Jared W. Singer At the Cheever Mine, located in the eastern Adirondack Mountains of the Mesoproterozoic Grenville Province, iron oxide-apatite ore forms a narrow (<3 m) sheet cross-cutting metasomatically altered, magnetite-bearing, albite-rich leucogranitic host rocks of the Lyon Mountain Granite suite. Zircon from the ore and five samples of country rock were dated by Laser Ablation-Multi-Collector-Inductively Coupled Plasma-Mass Spectrometry. The ore yielded a Concordia age of 1033.6 ± 2.9 Ma while three samples of host rock yielded ages of 1036.3 ± 2.9, 1040 ± 11, and 1043.9 ± 4.1 Ma. Two additional samples of host rock yielded older ages of 1059.6 ± 3.4 and 1066.0 ± 6.3 Ma and contain zircon xenocrystic cores with 207Pb/206Pb ages up to 1242 Ma. The zircons analyzed, including those separated from the ore, have characteristics typically associated with an igneous origin including size, shape, inclusions, oscillatory zoning, typical chondrite-normalized REE patterns, U contents, and U/Th ratios. This data establishes the age of the ore and alteration and a temporal, and likely genetic, connection between the ore and members of the Lyon Mountain Granite suite. A model invoking melting of Shawinigan country rocks, magmatic differentiation, and long-lived magmatic and metasomatic input along extensional fault conduits is proposed for the ore’s genesis. At the Cheever Mine, magmatic hydrothermal fluids and/or post-intrusion alteration appears not to have had a major impact on zircon, which preserves original U-Pb systematics.
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  • 54
    Publication Date: 2018-09-10
    Description: Geosciences, Vol. 8, Pages 340: Numerical Modeling of Flow Patterns Applied to Analysis of Susceptibility to Movements of the Ground Geosciences doi: 10.3390/geosciences8090340 Authors: Marcelo Cando Jácome Antonio Martínez-Graña Mass movements in deformed areas of natural relief deformed by seismotectonic factors are one of the most destructive and recurrent natural hazards in the Republic of Ecuador, especially during intense rain periods, the El Niño phenomenon, or due to earthquakes such as the one that occurred on 16 April 2016 in the Ecuadorian coastline. This study proposes the application of Hydrological Model D8 and its derived morphometric parameters like slope, orientation of the slope, and curvatures, extracted from the high spatial resolution Digital Elevation Model (DEM), implemented in programs such as Rockworks 7 (gridzo), SURFER (downwards slope), ArcView (flowacc), and SAGA (curvatures) to obtain runoff flow, structural geological lineaments, and superficial deformations of the topographic relief that are the origin of erosion, superficial landslides, lateral propagation, of the rock–soil complex, mass flows, and deep gravitational deformations. This methodology has been validated in three locations with intense deformations: two in Ecuador and one in Spain. The DEM were obtained from the Ecuadorian Spatial Institute (ESI) (spatial resolution of 10 m), the Rural Technological Infrastructure and Information National System (SIGTIERRAS) (spatial resolution of 5 m), and the Council of Andalusia (spatial resolution of 5 m).
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  • 55
    Publication Date: 2018-09-15
    Description: Geosciences, Vol. 8, Pages 347: Indoor Multi-Risk Scenarios of Climate Change Effects on Building Materials in Scandinavian Countries Geosciences doi: 10.3390/geosciences8090347 Authors: Arian Loli Chiara Bertolin Within the built environment, historic buildings are among the most vulnerable structures to the climate change impact. In the Scandinavian countries, the risk from climatic changes is more pronounced and the right adaptation interventions should be chosen properly. This article, through a multidisciplinary approach, links the majority of climate-induced decay variables for different building materials with the buildings’ capacity to change due to their protection status. The method tends to be general as it assesses the decay level for different building materials, sizes, and locations. The application of the method in 38 locations in the Scandinavian countries shows that the risk from climatic changes is imminent. In the far future (2071–2100), chemical and biological decays will slightly increase, especially in the southern part of the peninsula, while the mechanical decay of the building materials kept indoors will generally decrease. Furthermore, the merge of the decay results with the protection level of the building will serve as a good indicator to plan the right level and time of intervention for adapting to the future climatic changes.
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  • 56
    Publication Date: 2018-09-15
    Description: Geosciences, Vol. 8, Pages 349: Study and Characterization of Environmental Deposition on Marble and Surrogate Substrates at a Monumental Heritage Site Geosciences doi: 10.3390/geosciences8090349 Authors: Paola Fermo Sara Goidanich Valeria Comite Lucia Toniolo Davide Gulotta In this study, the results of the field exposure activity conducted between 2014 and 2017 on the façade of the Milano cathedral (Italy) are reported. The main research aim was to characterize environmental deposition in real exposure conditions and for this purpose, both stone substrates (Candoglia marble) and surrogate substrates (quartz fibre filters) were exposed on the cathedral façade in two sites at different heights. A complete chemical characterization has been performed on quartz filters and marble substrates, i.e., quantification of the deposited aerosol particulate matter (PM) and of the main ions. On quartz filters, the carbonaceous component of deposits was also investigated, as well as the color change induced by soiling, by means of colorimetric measurements. The combined approach exploiting marble and surrogate substrates seems to be a suitable monitoring strategy, although some aspects should be taken into account. In particular, differences in the deposits composition have been highlighted mainly depending on the type of substrate. The environmental data related to atmospheric pollution in Milan for the same period have also been considered but no direct correlations were found between some atmospheric precursors and their related ions in solid deposits.
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  • 57
    Publication Date: 2018-09-15
    Description: Geosciences, Vol. 8, Pages 348: Detection and Geometrical Characterization of a Buried Landfill Site by Integrating Land Use Historical Analysis, Digital Photogrammetry and Airborne Lidar Data Geosciences doi: 10.3390/geosciences8090348 Authors: Giuseppe Esposito Fabio Matano Marco Sacchi Abandoned quarries are frequently used as sites of illegal dumping of solid urban waste. These sites often occur nearby or within urban areas so that their detection may turn out to be quite difficult from the surface. This study focuses on the detection and geometrical characterization of a hidden landfill site located along the coastline of the Campi Flegrei, near Naples, Italy. Our approach is based on the analysis of historical topographic maps and aerial photographs, coupled with quantitative comparison of multitemporal digital elevation models obtained by digital photogrammetry and lidar techniques. The comparative analysis of topographic maps and aerial photos clearly shows modifications of the landscape associated with the urban development and quarrying activity, as well as the later filling of the quarry. The change detection analysis reveals that remarkable elevation changes occurred in the study area between 1956 and 2008. The average thickness of the landfill deposits is ca. 8 m, whereas the average volume is ca. 100,000 m3. The results of this work confirm the suitability of the used methodological approach that combines both qualitative and quantitative techniques for the detection of buried landfill sites. The geometric characterization of a landfill represents a fitting starting point for the further planning of geophysical site surveys and direct investigations aimed at the assessment of environmental hazards.
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    Topics: Geosciences
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  • 58
    Publication Date: 2018-04-21
    Description: Geosciences, Vol. 8, Pages 139: A Javascript GIS Platform Based on Invocable Geospatial Web Services Geosciences doi: 10.3390/geosciences8040139 Authors: Konstantinos Evangelidis Theofilos Papadopoulos Semantic Web technologies are being increasingly adopted by the geospatial community during last decade through the utilization of open standards for expressing and serving geospatial data. This was also dramatically assisted by the ever-increasing access and usage of geographic mapping and location-based services via smart devices in people’s daily activities. In this paper, we explore the developmental framework of a pure JavaScript client-side GIS platform exclusively based on invocable geospatial Web services. We also extend JavaScript utilization on the server side by deploying a node server acting as a bridge between open source WPS libraries and popular geoprocessing engines. The vehicle for such an exploration is a cross platform Web browser capable of interpreting JavaScript commands to achieve interaction with geospatial providers. The tool is a generic Web interface providing capabilities of acquiring spatial datasets, composing layouts and applying geospatial processes. In an ideal form the end-user will have to identify those services, which satisfy a geo-related need and put them in the appropriate row. The final output may act as a potential collector of freely available geospatial web services. Its server-side components may exploit geospatial processing suppliers composing that way a light-weight fully transparent open Web GIS platform.
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  • 59
    Publication Date: 2018-04-22
    Description: Geosciences, Vol. 8, Pages 140: Proximal Monitoring of the 2011–2015 Etna Lava Fountains Using MSG-SEVIRI Data Geosciences doi: 10.3390/geosciences8040140 Authors: Stefano Corradini Lorenzo Guerrieri Valerio Lombardo Luca Merucci Massimo Musacchio Michele Prestifilippo Simona Scollo Malvina Silvestri Gaetano Spata Dario Stelitano From 2011 to 2015, 49 lava fountains occurred at Etna volcano. In this work, the measurements carried out from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument, on board the Meteosat Second Generation (MSG) geostationary satellite, are processed to realize a proximal monitoring of the eruptive activity for each event. The SEVIRI measurements are managed to provide the time series of start and duration of eruption and fountains, Time Averaged Discharge Rate (TADR) and Volcanic Plume Top Height (VPTH). Due to its temperature responsivity, the eruptions start and duration, fountains start and duration and TADR are realized by exploiting the SEVIRI 3.9 μm channel, while the VPTH is carried out by applying a simplified procedure based on the SEVIRI 10.8 μm brightness temperature computation. For each event, the start, duration and TADR have been compared with ground-based observations. The VPTH time series is compared with the results obtained from a procedures-based on the volcanic cloud center of mass tracking in combination with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectories. The results indicate that SEVIRI is generally able to detect the start of the lava emission few hours before the ground measurements. A good agreement is found for both the start and the duration of the fountains and the VPTH with mean differences of about 1 h, 50 min and 1 km respectively.
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  • 60
    Publication Date: 2018-04-23
    Description: Geosciences, Vol. 8, Pages 141: The Monetary Measurement of Flood Damage and the Valuation of the Proactive Policies in Sicily Geosciences doi: 10.3390/geosciences8040141 Authors: Maria Rosa Trovato Salvatore Giuffrida Although floods, as well as other natural disasters, can be considered as relevant causes of intra-generational inequalities, frequent catastrophes and the resulting damage to the territory can be seen as a consequence of a generalized indifference about future. Land protection is one of the societal issues typically concerning inter-generational solidarity, involving the administrative system in the implementation of proactive policies. In the last three decades, the widespread demand for subsidiarity has made local communities more and more independent, so that attention to the long-term effects—typically concerning the territorial system as a whole at geographical scale—has been dispersed, and the proactive policies that come from the central government have become more ineffective. Regarding the case of the 2009 flood in the Fiumedinisi-Capo Peloro river basin in North Eastern Sicily, we propose an economic valuation of the land protection policy. This valuation, compared to the cost of recovery of the damaged areas, can provide helpful information on the decision-making process concerning the trade-off between reactive and proactive land policy. The economic value of land protection was calculated by means of the method of the imputed preferences, to obtain a real measure of the social territorial value from the point of view of the harmony between social system and environment. This method consists of an estimate based on the attribution of the expenditures according to the importance of the different areas. Since the value of land protection has been calculated by discounting the expenditures stream, some considerations about the economic significance of the proactive policy are referred to the role played by the social discount rate in the inter-temporal economic calculation.
    Electronic ISSN: 2076-3263
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  • 61
    Publication Date: 2018-04-24
    Description: Geosciences, Vol. 8, Pages 145: Spectral Signature Characterization and Remote Mapping of Oman Exotic Limestones for Industrial Rock Resource Assessment Geosciences doi: 10.3390/geosciences8040145 Authors: Sankaran Rajendran Sobhi Nasir Mohammed El-Ghali Khaled Alzebdah Ali Salim Al-Rajhi Mohammed Al-Battashi This study demonstrates the capability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor data to remotely map industrial carbonate rocks known as the ‘Oman exotics’ of the Sultanate of Oman. We measured reflectance spectra of marble using a PIMA™ spectrometer and studied their spectral absorptions distinguishing calcite from spectral absorptions of dolomite of the same region. The spectral band 8 of ASTER is processed by simple decorrelation stretch image processing method to map the exotic limestone rock of the Nakhl region, Oman. Results showed that carbonate rocks displayed distinctive tonal variation on the image. A comparative study with the spectral band 7 of Landsat 7 (ETM+) does not discriminate the calcite-bearing marbles and associated carbonate formations in the studied area. ASTER data were also processed by the application of the Maximum Likelihood Classification (MLC), Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) image classification algorithms. The results were assessed by the production of a confusion matrix. The study shows the capability of visible near infrared (VNIR) and shortwave infrared (SWIR) spectral bands of the ASTER sensor and potential of the image processing methods to remotely identify industrial carbonate rocks and we recommend this technique to similar regions of the world.
    Electronic ISSN: 2076-3263
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  • 62
    Publication Date: 2018-04-24
    Description: Geosciences, Vol. 8, Pages 143: Topographic Effects in Geoid Determinations Geosciences doi: 10.3390/geosciences8040143 Authors: Lars E. Sjöberg Traditionally, geoid determination is applied by Stokes’ formula with gravity anomalies after removal of the attraction of the topography by a simple or refined Bouguer correction, and restoration of topography by the primary indirect topographic effect (PITE) after integration. This technique leads to an error of the order of the quasigeoid-to-geoid separation, which is mainly due to an incomplete downward continuation of gravity from the surface to the geoid. Alternatively, one may start from the modern surface gravity anomaly and apply the direct topographic effect on the anomaly, yielding the no-topography gravity anomaly. After downward continuation of this anomaly to sea-level and Stokes integration, a theoretically correct geoid height is obtained after the restoration of the topography by the PITE. The difference between the Bouguer and no-topography gravity anomalies (on the geoid or in space) is the “secondary indirect topographic effect”, which is a necessary correction in removing all topographic signals. In modern applications of an Earth gravitational model (EGM) in geoid determination a topographic correction is also needed in continental regions. Without the correction the error can range to a few metres in the highest mountains. The remove-compute-restore and Royal Institute of Technology (KTH) techniques for geoid determinations usually employ a combination of Stokes’ formula and an EGM. Both techniques require direct and indirect topographic corrections, but in the latter method these corrections are merged as a combined topographic effect on the geoid height. Finally, we consider that any uncertainty in the topographic density distribution leads to the same error in gravimetric and geometric geoid estimates, deteriorating GNSS-levelling as a tool for validating the topographic mass distribution correction in a gravimetric geoid model.
    Electronic ISSN: 2076-3263
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  • 63
    Publication Date: 2018-04-24
    Description: Geosciences, Vol. 8, Pages 142: Site Effect Assessment of the Gros-Morne Hill Area in Port-au-Prince, Haiti, Part A: Geophysical-Seismological Survey Results Geosciences doi: 10.3390/geosciences8040142 Authors: Sophia Ulysse Dominique Boisson Claude Prépetit Hans-Balder Havenith After the M = 7.0 Haiti earthquake in 2010, many teams completed seismic risk studies in Port-au-Prince to better understand why this not extraordinarily strong event had induced one of the most severe earthquake disasters in history (at least in the Western World). Most highlighted the low construction quality as the main cause for the disaster, but some also pointed to possible soil and topographic amplification effects, especially in the lower and central parts of Port-au-Prince (e.g., close to the harbor). However, very detailed local studies of such site effects have not been completed yet. A Belgian-Haitian collaboration project was established in order to develop a detailed local seismic hazard study for Gros-Morne hill located in the district of Pétion-Ville, southeast of Port-au-Prince. In order to have a better understanding of the amplification on the Gros-Morne hill, in the southeastern part of Port-au-Prince, site effects were investigated by using near surface geophysical methods. The horizontal to vertical spectral ratio technique was applied to ambient vibrations and earthquake data, and multichannel analysis of surface waves and P-wave refraction tomography calculation were applied to seismic data. Standard spectral ratios were computed for the S-wave windows of the earthquake data recorded by a small temporary seismic network. Electrical resistivity tomography profiles were also performed in order to image the structure of the subsurface and detect the presence of water, if any. The spectral ratio results generally show low to medium (1.5–6) resonance amplitudes at one or several different resonance frequencies (for the same site), between 0.5 and 25 Hz. At most of the investigated sites, the fundamental resonance frequency varies between 7 and 10 Hz. By using the multichannel surface wave analyses of the seismic data, we were able to determine shear wave velocities ranging between 200 and 850 m/s, up to a depth of about 15–20 m. From the refraction analysis, we were able to delineate P-waves velocities of 500 to 1500–2000 m/s at the studied sites. The outputs were locally compared with the resistivity data from the electrical profiles. Thus, the overall data indicate a moderate site effect at Gros-Morne hill, with a great variability in site amplification distribution. Initial estimates of local site effects were made on the basis of those outputs and the earthquake recordings. Our results are finally discussed with respect to outputs and interpretations that had been published earlier for the same site. Those results only partly confirm the strong seismic amplification effects highlighted by previous papers for this hill site, which had been explained by the effects of the local topographic and soil characteristics.
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  • 64
    Publication Date: 2018-04-24
    Description: Geosciences, Vol. 8, Pages 144: Dynamics of Carbonates in Soils under Different Land Use in Forest-Steppe Area of Russia Using Stable and Radiogenic Carbon Isotope Data Geosciences doi: 10.3390/geosciences8040144 Authors: Olga Khokhlova Tatyana Myakshina The work is aimed at the analysis of carbonate dynamics in soils under different land use. The studied area is located in the forest steppe - of the Central Russian Upland. Soils were sampled at four sites: a broadleaf forest, an adjacent 50-year continuously cropped field including plots under a corn monoculture, bare fallow, and a crop rotation area with a clean fallow every fourth year. The carbonates’ morphology, their chemical composition, as well as their stable and radiogenic isotopes of carbon were studied. Clear-cut distinctions were found in the carbonate distribution throughout the profiles in the microstructure of carbonate pedofeatures, carbon isotopic composition, and radiocarbon age of carbonates between the pairs of the plots as follows: the bare fallow and the crop rotation on the one hand, and the corn monoculture and forest on the other. The distinctions are commonly assumed to result from repeating upward water fluxes, which are different in the bare soils and those with plant cover. A clear difference occurred in the hydrothermal regime for soils with and without plant cover, and was found to be the key factor of the observed differences. In addition, in soils under plant cover, the carbonate migration upward occurs due to process of transpiration, whereas in soils devoid of plants, it occurs due to physical evaporation.
    Electronic ISSN: 2076-3263
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  • 65
    Publication Date: 2018-04-27
    Description: Geosciences, Vol. 8, Pages 150: Assessing the Protective Capacity of Aquifers Using Very-Low-Frequency Electromagnetic Survey Geosciences doi: 10.3390/geosciences8050150 Authors: Oghenero Ohwoghere-Asuma Kizito Ejiro Aweto Felix I. Chinyem Hyacinth O. Nwankwoala The protective capacity of aquifers is a prerequisite for groundwater quality in areas prone to contamination from the ground surface. Aquifers without protective layers are more susceptible to contaminations from point and non-point sources. The protective capacity of an aquifer significantly correlates with the thickness of clay and organic materials that mantled it. To assess aquifer protective capacity, electrical conductivity property of saturated clay was determined from filtered imaginary and real components of Very Low-Frequency Electromagnetic (VLF-EM). The filtered real components against distance and current density pseudo-section produced from real components were concomitantly used for interpretation. Clays capping aquifers were delineated from those without capping from low and high values of filtered imaginary and real components and current density pseudo-section. The distribution of clay laterally across the area indicates that aquifers are poorly protected and susceptible to contaminations from a point and non-point sources. The apparent agreement between inferred geology from VLF-EM interpretation, borehole data and resistivity data underscores the efficacy of VLF-EM as an important tool that can be used or combined with other geophysical methods and borehole information/data for assessment of the protective capacity of the aquifer.
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  • 66
    Publication Date: 2018-04-28
    Description: Geosciences, Vol. 8, Pages 152: High-Resolution Topographic Analyses of Mounds in Southern Acidalia Planitia, Mars: Implications for Possible Mud Volcanism in Submarine and Subaerial Environments Geosciences doi: 10.3390/geosciences8050152 Authors: Ryodo Hemmi Hideaki Miyamoto A northern ocean of Mars is still debated and, if it existed, it may have accompanied valley networks and/or outflow channels, which may have led to the emplacement of a large amount of water to the northern lowlands during the Noachian and/or Hesperian times. However, it is unclear how and under what conditions (submarine or subaerial) geologic features such as mounds and giant polygons formed in the northern lowlands. The densely-distributed mounds in Chryse and Acidalia Planitia, >1000 km-wide basins of the northern plains, were suggested to be ancient mud volcanoes formed in an aqueous setting, which is controversial (i.e., mud vs. igneous and submarine vs. subaerial). However, these mounds have not been quantitatively well characterized, particularly with respect to their detailed topography. Here we generated forty digital elevation models (DEMs) with resolution of up to 1 m/pixel from High Resolution Imaging Science Experiment (HiRISE) stereo image pairs, and we accurately measured the morphometric parameters of ~1300 mounds within the southern part of the Acidalia basin. Their heights and diameters resulted in good accordance with those of mud and igneous volcanoes in submarine/subaerial settings on Earth. Maximum depths of their source reservoirs vary from ~30 to ~450 m for a subaqueous setting and from ~110 to ~860 m for a subaerial setting, both of which are consistent with fluid expulsion from the ~100–4500 m-thick flood deposits (Vastitas Borealis Formation, VBF). On the basis of the morphometric values, we estimated rheological properties of materials forming the mounds and found them consistent with a mud flow origin, which does not rule out an igneous origin. The conditions of possible submarine mud or igneous volcanoes may have harbored less hazardous environments for past life on Mars than those on an ocean-free surface.
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  • 67
    Publication Date: 2018-05-01
    Description: Geosciences, Vol. 8, Pages 158: Volcanic Plumes: Impacts on the Atmosphere and Insights into Volcanic Processes Geosciences doi: 10.3390/geosciences8050158 Authors: Andrew J. S. McGonigle Pasquale Sellitto Giuseppe G. Salerno Here we introduce a Special Issue of Geosciences focused on the scientific research field of ‘Volcanic Plumes: Impacts on the atmosphere and insights into volcanic processes’ [...]
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  • 68
    Publication Date: 2018-05-05
    Description: Geosciences, Vol. 8, Pages 164: Validating Rainfall-Runoff Modelling Using Satellite-Based and Reanalysis Precipitation Products in the Sre Pok Catchment, the Mekong River Basin Geosciences doi: 10.3390/geosciences8050164 Authors: Thu Ha Nguyen Ilyas Masih Yasir A. Mohamed Pieter van der Zaag The limitation in quantity and quality of climate data, in particular rainfall measurements, directly affects the reliability of hydrological models, which negatively impacts on the quality of water resources planning and management. This is obviously true in poorly-gauged or in transboundary river catchments with limited practice of data sharing among the riparian states. Satellite-based and reanalysis rainfall products are increasingly recognised as a promising information source to supplement ground observations. This research aims to study the feasibility of using satellite-based and reanalysis rainfall data for rainfall-runoff modelling in the Sre Pok catchment-a poorly gauged catchment located in Vietnam and Cambodia. First, three selected rainfall products (Tropical Rainfall Measuring Mission-TRMM, CPC MORPHing Technique-CMORPH, and European Reanalysis-ERA-Interim) were compared against ground rainfall data of 13 rain-gauges, located inside and in the vicinity of the study catchment. The validation results show that the studied global datasets have a reasonably good correlation with ground observation at monthly time scale (NSE = 0.3 to 0.8, R2 = 0.4 to 0.8), but relatively poor correlation at daily scale (NSE = −0.4 to 0.3, R2 = 0.1 to 0.4). Next, a semi-distributed rainfall-runoff model based on HBV-Light was developed to validate these datasets in the Krong Ana sub-catchment of the Sre Pok. The results illustrate satisfactory to very good model performances at monthly time scale for the satellite-based and reanalysis rainfall inputs (NSE = 0.58 to 0.77, R2 = 0.59 to 0.78 for the calibration period from 2004 to 2007, while NSE = 0.59 to 0.80, R2 = 0.64 to 0.84 for the validation period from 2008 to 2010). However, only TRMM and ERA-Interim give acceptable results at daily scale with NSE = 0.52 to 0.67, R2 = 0.53 to 0.67 for the calibration period, and NSE = 0.41 to 0.61, R2 = 0.45 to 0.65 for the validation period. The study concludes that the tested satellite-based and reanalysis rainfall products, especially TRMM and ERA-Interim, could mimic reasonably well the monthly rainfall pattern in the study region. It also demonstrates a great opportunity to use satellite-based and reanalysis rainfall for runoff modelling at monthly time scale in the Sre Pok catchment and other poorly-gauged (transboundary) catchments in the region, for example in the Mekong and Red River Basins.
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  • 69
    Publication Date: 2018-05-05
    Description: Geosciences, Vol. 8, Pages 163: Temporal and Spatial Variability of Sediment Transport in a Mountain River: A Preliminary Investigation of the Caldone River, Italy Geosciences doi: 10.3390/geosciences8050163 Authors: Davide Brambilla Monica Papini Laura Longoni Sediment transport is a key evolution process of rivers and water basins. This process can pose flood hazards to nearby areas. The Eulerian and Lagrangian methods are usually employed to describe sediment transport in mountain rivers. The application of different methods was proposed by scientists to analyze specific aspects of solid transport, however a complete understanding still alludes us. After a brief review of the most common methods, the coupling of three different methods is proposed and tested in order to study sediment dynamics, and its spatial and temporal variability, in mountain rivers. Tracers, painted bed patches, and digital elevation model (DEM) comparisons are used to characterize sediment transport at both a micro-scale short-term and a macro-scale long-term level on a test reach on Caldone River, Italy. Information about travel distance, critical diameters, active width, and morphological evolution was sought. We focused on how water discharge is changing the relationships between different measurement techniques. High discharge events force the channel to behave in a unique way, while low discharge events generate more intrinsic variability. Only measurement technique coupling can overcome this issue. Results are encouraging and show the potential of a mixed Eulerian-Lagrangian approach.
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  • 70
    Publication Date: 2018-05-08
    Description: Geosciences, Vol. 8, Pages 168: Variability of Shelf Growth Patterns along the Iberian Mediterranean Margin: Sediment Supply and Tectonic Influences Geosciences doi: 10.3390/geosciences8050168 Authors: Ruth Durán Francisco José Lobo Marta Ribó Marga García Luis Somoza Clinoform depositional features along the Iberian Mediterranean margin are investigated in this study, with the aim of establishing the causes of their varied shapes and other characteristics. We have analyzed the broad-scale margin physiography and seismic stratigraphic patterns based on high-resolution bathymetric data and previously interpreted seismic data. In addition, we have evaluated regional supply conditions and the uplift-subsidence regime of the different shelf sectors. The upper Quaternary record is strongly dominated by shelf-margin regressive wedges affected by the prevailing 100 ka cyclicity. However, the margins exhibit considerable lateral variability, as the result of the balance between the amount of sediment supply and the uplift-subsidence relationship. Three major shelf sectors with distinct morpho-sedimentary features have been defined. The relatively narrow northern shelves (Roses, La Planassa and Barcelona) are supplied by discrete river outlets that collectively constitute a linear source and are mainly affected by tectonic tilting. The wide middle shelves (Ebro Shelf, the Gulf of Valencia, and the Northern Arc) receive the sediment supply from the large Ebro River and other medium rivers. Although the tectonic regime changes laterally (strong subsidence in the north and uplift in the south), shelf growth is maintained by lateral advection of sediments. The southern shelves (the Southern Arc and the northern Alboran Shelf) are very abrupt and narrow because of the uplifting Betic Cordillera, and the torrential fluvial regimes that determine a very efficient sediment by-pass toward the deep basin. Submarine canyons deeply incised in the continental margin constitute a key physiographic feature that may enhance the transport of sediment to the deep sea or individualize shelf sectors with specific sedimentation patterns, as occurs in the Catalan margin.
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  • 71
    Publication Date: 2018-05-11
    Description: Geosciences, Vol. 8, Pages 172: Multicamera, Multimethod Measurements for Hydromorphologic Laboratory Experiments Geosciences doi: 10.3390/geosciences8050172 Authors: Alessio Radice Barbara Zanchi The realization of hydromorphologic laboratory experiments on the propagation of aggrading or degrading sediment fronts requires simultaneous measurements of the sediment feeding rate, the profile of the free surface, and the flume bed elevation. In this study, five action cameras and different image-processing techniques were employed to measure all the needed quantities automatically and with adequate temporal resolution. The measurement of the sediment feeding rate was determined by particle image velocimetry as a surrogate, correlated quantity: the surface velocity of the sediment flow along a vibrating channel was used as an upstream feeder. The profile of the free surface was measured by shooting an array of piezometers connected to the flume. Each piezometer pipe contained a buoyant black sphere that could be recognized by using tools for particle identification, thus determining the elevation of the free surface above the piezometric probe. Finally, the bed profile along the flume was measured at any instant by edge detection, locating the transition from a water layer to a sediment layer in images taken from the side of the flume. The paper describes the instrumentation and the methods, finally presenting the results obtained from a prototypal experiment. Potentialities and limitations of the proposed methods are discussed, together with some prospects on future use in systematic experimental campaigns.
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  • 72
    Publication Date: 2018-06-01
    Description: Geosciences, Vol. 8, Pages 197: Geodiversity Research Methods in Geotourism Geosciences doi: 10.3390/geosciences8060197 Authors: Magdalena Kuleta With the emerging new approaches in the field of geodiversity, we can get better use of geographic space in geoparks and increase the number of geotourism destinations. Depending on what we want to study in geodiversity, a suitable research method should be adopted. No method is wrong, because various features of objects be examined this manner. In this study, the main objective is to identify and present not only quantitative but also qualitative character of geodiversity issue. Qualitative and quantitative features of objects based on appropriate categorization and their reference to scales, are to designate areas suitable for sustainable geotourism. It is important to develop a methodological approach in line with the chosen objective. The following material is a presentation of the most frequently used methods in the geodiversity of their purposes and use in geotourism.
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  • 73
    Publication Date: 2018-06-01
    Description: Geosciences, Vol. 8, Pages 198: Volcanic Plume Impact on the Atmosphere and Climate: O- and S-Isotope Insight into Sulfate Aerosol Formation Geosciences doi: 10.3390/geosciences8060198 Authors: Erwan Martin The impact of volcanic eruptions on the climate has been studied over the last decades and the role played by sulfate aerosols appears to be major. S-bearing volcanic gases are oxidized in the atmosphere into sulfate aerosols that disturb the radiative balance on earth at regional to global scales. This paper discusses the use of the oxygen and sulfur multi-isotope systematics on volcanic sulfates to understand their formation and fate in more or less diluted volcanic plumes. The study of volcanic aerosols collected from air sampling and ash deposits at different distances from the volcanic systems (from volcanic vents to the Earth poles) is discussed. It appears possible to distinguish between the different S-bearing oxidation pathways to generate volcanic sulfate aerosols whether the oxidation occurs in magmatic, tropospheric, or stratospheric conditions. This multi-isotopic approach represents an additional constraint on atmospheric and climatic models and it shows how sulfates from volcanic deposits could represent a large and under-exploited archive that, over time, have recorded atmospheric conditions on human to geological timescales.
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  • 74
    Publication Date: 2018-05-31
    Description: Geosciences, Vol. 8, Pages 194: The Glacial Geomorphology of the Ice Cap Piedmont Lobe Landsystem of East Mýrdalsjökull, Iceland Geosciences doi: 10.3390/geosciences8060194 Authors: David Evans Marek Ewertowski Chris Orton David Graham A surficial geology and geomorphology map of the forelands of the Sandfellsjökull and Oldufellsjökull piedmont lobes of the east Mýrdalsjökull ice cap is used to characterise the historical and modern landscape imprint in a glacial landsystems context. This serves as a modern analogue for palaeoglaciological reconstructions of ice cap systems that operated outlet lobes of contrasting dynamics, but the subtle variability in process-form regimes is encoded in the geomorphology. The landsystems of the two piedmont lobes reflect significantly different process-form regimes, and hence contrasting historical glacier dynamics, despite the fact that they are nourished by the same ice cap. The Sandfellsjökull landsystem displays the diagnostic criteria for active temperate glacier operation, including arcuate assemblages of inset minor push moraines and associated flutings, kame terrace and ice-dammed lake deposits, linear sandar directed by overridden moraine arcs, and since 1945, features, such as ice-cored, pitted, and glacially pushed outwash fans that are linked to englacial esker networks representative of recession into an overdeepening. Moraine plan forms have also changed from weakly crenulated and discontinuous curvilinear ridges to sawtooth features and crevasse-squeeze ridges and till eskers in response to changing proglacial drainage conditions. The Oldufellsjökull landsystem displays subtle signatures of jökulhlaup-driven surges, including sparse and widely spaced moraine clusters that are separated by exceptionally long flutings. The subtlety of the surge imprint at Oldufellsjökull was recognised only by comparison with nearby Sandfellsjökull, suggesting that palaeo-surging has likely been under-estimated in the ancient landform record. Hence, the simple imprint of sparse and widely spaced moraine clusters that are separated by exceptionally long flutings should be included as possible surge-diagnostic criteria.
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  • 75
    Publication Date: 2018-06-02
    Description: Geosciences, Vol. 8, Pages 199: Matrix of Priorities for the Management of Visitation Impacts on the Geosites of Araripe UNESCO Global Geopark (NE Brazil) Geosciences doi: 10.3390/geosciences8060199 Authors: Eduardo S. Guimarães Artur Sá Ronaldo Gabriel Helena Moreira Jaqueliny R. S. Guimarães Paulo Felipe R. Bandeira João Marcos F. de Lima Silva Rafael C. Soares José Patrício P. Melo In order to safeguard the material and immaterial heritage and to foster delightful experiences for visitors, this investigation aimed to define a Matrix of Priorities for management of Visitation Impacts Management on the Geosites of Araripe UNESCO Global Geopark. With a quantitative approach involving the revision of documents, the methods used in this paper determined what the demands for visitation are as well as the impacts of these demands. We identified the offers for activities and occurrences in the geosites. Using this model, we calculated the following variables: (i) evident impacts, (ii) management profile, (iii) visitor demand and (iv) activity zone. We also classified the recommended management actions and presented the priority matrix. We classified the geosites of Ponte de Pedra, Riacho do Meio and Cachoeira de Missão Velha as requiring immediate or priority management action, in view of the high impacts of visitation evidenced. The geosites of Pedra Cariri, Floresta Petrificada and Parque dos Pterossauros were classified as programmed action, highlighting the difficulty of accessing them and the low demand for visitation. The geosites Pontal de Santa Cruz, Colina do Horto and Batateiras presented the best scores and require feedback action. It is emphasized that the deepening the investigations is required in order to produce and interpret the data complexity that guides the management of a dynamic territory such as a UNESCO Global Geopark.
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  • 76
    Publication Date: 2018-07-01
    Description: Geosciences, Vol. 8, Pages 243: PHOTOSED—PHOTOgrammetric Sediment Erosion Detection Geosciences doi: 10.3390/geosciences8070243 Authors: Markus Noack Gerhard Schmid Felix Beckers Stefan Haun Silke Wieprecht This work presents a novel high-resolution photogrammetric measuring technique (PHOTOSED) to study in detail the erosion behavior of cohesive sediments, or cohesive/non-cohesive sediment mixtures. PHOTOSED uses a semiconductor laser to project a pseudo-random pattern of light points on a sediment surface and applies the Dense Optical Flow (DOF) algorithm to measure the erosion volume based on displacements of the projected light points during the sediment erosion process. Based on intensive calibration and verification experiments, the accuracy and applicability of the method has been validated for a wide range of erosion volumes, encompassing several orders of magnitude, which is required for investigations of natural sediment mixtures. The high spatial resolution of PHOTOSED is especially designed to detect the substantial variability of erosion rates during exemplary erosion experiments, which allows for further in-depth investigations of the erosion process of cohesive sediments and cohesive/non-cohesive sediment mixtures.
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  • 77
    Publication Date: 2018-07-03
    Description: Geosciences, Vol. 8, Pages 244: Landscape Classification with Deep Neural Networks Geosciences doi: 10.3390/geosciences8070244 Authors: Daniel Buscombe Andrew C. Ritchie The application of deep learning, specifically deep convolutional neural networks (DCNNs), to the classification of remotely-sensed imagery of natural landscapes has the potential to greatly assist in the analysis and interpretation of geomorphic processes. However, the general usefulness of deep learning applied to conventional photographic imagery at a landscape scale is, at yet, largely unproven. If DCNN-based image classification is to gain wider application and acceptance within the geoscience community, demonstrable successes need to be coupled with accessible tools to retrain deep neural networks to discriminate landforms and land uses in landscape imagery. Here, we present an efficient approach to train/apply DCNNs with/on sets of photographic images, using a powerful graphical method called a conditional random field (CRF), to generate DCNN training and testing data using minimal manual supervision. We apply the method to several sets of images of natural landscapes, acquired from satellites, aircraft, unmanned aerial vehicles, and fixed camera installations. We synthesize our findings to examine the general effectiveness of transfer learning to landscape-scale image classification. Finally, we show how DCNN predictions on small regions of images might be used in conjunction with a CRF for highly accurate pixel-level classification of images.
    Electronic ISSN: 2076-3263
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  • 78
    Publication Date: 2018-07-06
    Description: Geosciences, Vol. 8, Pages 247: Pb Isotope Mapping of Paleoproterozoic Gneisses in the SW Grenville Province: Evidence for a Cryptic Continental Suture Geosciences doi: 10.3390/geosciences8070247 Authors: Gabriel A. Arcuri Alan P. Dickin New whole-rock lead (Pb) isotope analyses are presented in this study for granitoid orthogneisses from the Southwest Grenville Province in Ontario and Western Quebec. These data are used to test the location of a cryptic Archean-Proterozoic suture proposed on the basis of neodymium (Nd) isotope mapping. Immediately south of the inferred suture boundary, Pb isotope results show a crustal component derived solely from a juvenile Paleoproterozoic mantle source. These data are distinctly different from the reworked Archean craton to the northwest and strongly support the boundary derived from Nd isotope data. Pb signatures in the Paleoproterozoic crust suggest a southerly increase in magmatic reworking due to intensive plutonism during the late Paleoproterozoic and early Mesoproterozoic periods. The accretion of a juvenile arc to the Archean margin during the Penokean event (ca. 1.85 Ga) would have triggered subduction-zone reversal and the development of a long-lived ensialic arc on the composite margin. This was expressed as a 1.75 Ga Killarnian magmatic event and subsequent early Mesoproterozoic magmatism. This tectonic model for the Southwest Grenville Province shows that its crustal evolution is consistent with the Paleoproterozoic Makkovik-Ketilidian Orogen of Labrador and Southern Greenland. Hence, the application of whole-rock Pb isotope data in conjunction with Nd model ages provides data useful for mapping the extent of crustal terranes of differing age, which is essential for modeling the tectonic evolution of complex ancient accretionary orogens.
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  • 79
    Publication Date: 2018-07-10
    Description: Geosciences, Vol. 8, Pages 252: Development of a General Protocol to Enhance the Hydrological Analysis Techniques for Urban Catchments in Ireland Geosciences doi: 10.3390/geosciences8070252 Authors: Elisa Longo John Paul Rooney The hydrological analysis of urban catchments is a critical consideration for all major civil engineering projects. The purpose of this article is to develop a general protocol to enhance the established techniques for estimating runoff from Irish urban catchments. The chosen case study is the Rye Water catchment, which is covering two significant urban centres, Maynooth and Leixlip. The findings were compared with the flow data available on the Office of Public Works (OPW) website, to verify the reliability of the proposed approach. The study showed that the methodology described in this paper is applicable to Irish catchments and the protocol, with minor improvements can be adopted in Ireland to support designers in their approach to extreme rainfall events.
    Electronic ISSN: 2076-3263
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  • 80
    Publication Date: 2018-07-11
    Description: Geosciences, Vol. 8, Pages 256: The Majella National Park: An Aspiring UNESCO Geopark Geosciences doi: 10.3390/geosciences8070256 Authors: Elena Liberatoscioli Giancarlo Boscaino Silvano Agostini Adele Garzarella Etta Patacca Scandone Majella National Park is located in the central Apennines (Italy), in a vast mountainous area of about 740 km2. Owing to the complex geological history of the Majella Massif and surrounding areas, it features many different landforms. Woodlands rich in water characterize the wide tectonic depression of Caramanico, which separates the rounded gentle profile of the Majella to the east from the impervious steep slope of the Morrone Mt. to the west. Bare pitted highlands, like lunar landforms, characterize the top of the Majella (i.e., Femmina Morta Valley) shaped by flowing ice that long ago covered the higher parts of the massif. Sedimentary structures and fossil content recovered in carbonates attest to a long period of sedimentation in warm, shallow-marine environments, revealing that the Majella and the surrounding carbonate mountains looked, approximately from 140 to 7 Ma, like the present-day Bahamas and Persian Gulf. The Park hosts at least 95 geosites, some of which (22) are well-known in the international literature because of their scientific relevance. In addition, its natural and cultural wealth, deeply fused together with geoheritage, preserves several features of national and world rarity. Therefore, the Park Authority decided to put forward its territory as a candidate to become part of the United Nations Educational, Scientific and Cultural Organization (UNESCO) Global Geoparks Network.
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  • 81
    Publication Date: 2018-07-11
    Description: Geosciences, Vol. 8, Pages 257: Controls on Deuterium Excess across Asia Geosciences doi: 10.3390/geosciences8070257 Authors: John Bershaw Deuterium excess (d-excess) is a second-order stable isotope parameter measured in meteoric water to understand both the source of precipitation and the evolution of moisture during transport. However, the interpretation of d-excess patterns in precipitation is often ambiguous, as changes in moisture source and processes during vapor transport both affect d-excess in non-unique ways. This is particularly true in Asia where continental moisture travels a long distance across diverse environments from unique moisture sources before falling as precipitation. Here, I analyzed published d-excess records from meteoric water throughout Asia to better characterize what influences d-excess values. I conclude that, (1) an increase in d-excess values with elevation up the windward side of mountain ranges and a marked decrease in d-excess into their rain shadows are primarily related to subcloud evaporation as opposed to moisture source mixing; (2) high d-excess values (>10‰) associated with the eastern Mediterranean Sea are lowered across much of Central Asia by the addition of other moisture sources, both oceanic and recycled continental; (3) subcloud evaporation of raindrops is lowering d-excess values of precipitation (<10‰) throughout the relatively arid Tarim Basin, China; and (4) temporal changes in d-excess values of alpine glaciers do reflect spatio-temporal changes in moisture source, as these samples experience minimal variation in subcloud evaporation.
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  • 82
    Publication Date: 2018-07-13
    Description: Geosciences, Vol. 8, Pages 262: A Special Issue of Geosciences: Groundwater Pollution Geosciences doi: 10.3390/geosciences8070262 Authors: Mastrocicco Micòl Colombani Nicolò n/a
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  • 83
    Publication Date: 2018-07-12
    Description: Geosciences, Vol. 8, Pages 258: Coastal Karst Groundwater in the Mediterranean: A Resource to Be Preferably Exploited Onshore, Not from Karst Submarine Springs Geosciences doi: 10.3390/geosciences8070258 Authors: Michel Bakalowicz Coastal karst aquifers are common in the Mediterranean basin. With their significant potential storage capacity, they are an attractive groundwater resource in areas where the water demand is the most important. They discharge either at the coastal zone or directly into the sea at karst submarine springs (KSMS). Decision makers take an interest in this unconventional groundwater resource and are convinced by companies and research consultancies that KSMS’s should be exploited because they would discharge huge amount of fresh water. Being now well documented, the occurrence of KSMS’s along the Mediterranean coast is discussed in the light of recent geological history favourable to the development of karst. Conduit flow conditions are common, inherited from an intense phase of karstification during the Messinian Crisis of Salinity at the end of Miocene, when the sea level was 1500 to 2500 m below present sea level. From investigations carried out along the coasts of France and the Levant, compared with studies done along other Mediterranean coastlines, it appears that capturing groundwater discharged at KSMS raises different problems which make the operation dicey and expansive.
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  • 84
    Publication Date: 2018-07-12
    Description: Geosciences, Vol. 8, Pages 260: How Characterization of Particle Size Distribution Pre- and Post-Reaction Provides Mechanistic Insights into Mineral Carbonation Geosciences doi: 10.3390/geosciences8070260 Authors: Aashvi Dudhaiya Rafael M. Santos Mineral carbonation is the conversion of carbon dioxide, in gas form or dissolved in water, to solid carbonates. Materials characterization plays an important role in assessing the potential to use these carbonates in commercial applications, and also aids in understanding fundamental phenomena about the reactions. This paper highlights findings of mechanistic nature made on topics related to mineral carbonation, and that were made possible by assessing particle size, particle size distribution, and other morphological characteristics. It is also shown how particle size data can be used to estimate the weathering rate of carbonated minerals. An extension of the carbonation weathering rate approach is presented, whereby using particle size distribution data it becomes possible to predict the particle size below which full carbonation is obtained, and above which partial carbonation occurs. The paper also overviews the most common techniques to determine the particle size distribution, as well as complementary and alternate techniques. In mineral carbonation research, most techniques have been used as ex situ methods, yet tools that can analyze powders during reaction (in situ and real-time) can provide even more insight into mineral carbonation mechanisms, so researchers are encouraged to adopt such advanced techniques.
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  • 85
    Publication Date: 2018-07-12
    Description: Geosciences, Vol. 8, Pages 259: Vegetated Channel Flows: Turbulence Anisotropy at Flow–Rigid Canopy Interface Geosciences doi: 10.3390/geosciences8070259 Authors: Gerardo Caroppi Paola Gualtieri Nicola Fontana Maurizio Giugni This laboratory study aimed at investigating the mean and turbulent characteristics of a densely vegetated flow by testing four different submergence ratios. The channel bed was covered by a uniform array of aligned metallic cylinders modeling rigid submerged vegetation. Instantaneous velocities, acquired with a three-component acoustic Doppler velocimeter (ADV), were used to analyze the mean and turbulent flow structure. The heterogeneity of the flow field was described by the distributions of mean velocities, turbulent intensities, skewness, kurtosis, Reynolds stresses, and Eulerian integral scales. The exchange processes at the flow–vegetation interface were explored by applying the turbulence triangle technique, a far less common technique for vegetated flows based on the invariant maps of the anisotropic Reynolds stress tensor.
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  • 86
    Publication Date: 2018-07-17
    Description: Geosciences, Vol. 8, Pages 263: Hf-Nd Isotopes in Archean Marine Chemical Sediments: Implications for the Geodynamical History of Early Earth and Its Impact on Earliest Marine Habitats Geosciences doi: 10.3390/geosciences8070263 Authors: Sebastian Viehmann The Hf-Nd isotope systems are coupled in magmatic systems, but incongruent Hf weathering (‘zircon effect’) of the continental crust leads to a decoupling of the Hf-Nd isotope systems in low-temperature environments during weathering and erosion processes. The Hf-Nd isotope record was recently dated back from the Cenozoic oceans until the Archean, showing that both isotope systems were already decoupled in seawater 2.7 Ga ago and potentially 3.4 Ga and 3.7 Ga ago. While there might have existed a hydrothermal pathway for Hf into Archean seawater, incongruent Hf weathering of more evolved, zircon-bearing uppermost continental crust that was emerged and available for subaerial weathering accounts for a significant decoupling of Hf-Nd isotopes in the dissolved (<0.2 µm) and suspended (>0.2 µm) fractions of Early Earth’s seawater. These findings contradict the consensus that uppermost Archean continental crust was (ultra)mafic in composition and predominantly submerged. Hence, Hf-Nd isotopes in Archean marine chemical sediments provide the unique potential for future research to trace the emergence of evolved continental crust, which in turn has major implications for the geodynamical evolution of Early Earth and the nutrient flux into the earliest marine habitats on Earth.
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  • 87
    Publication Date: 2018-07-21
    Description: Geosciences, Vol. 8, Pages 268: Diffuse Versus Conduit Flow in Coastal Karst Aquifers: The Consequences of Island Area and Perimeter Relationships Geosciences doi: 10.3390/geosciences8070268 Authors: Erik B. Larson John E. Mylroie The majority of limestone islands are made of eogenetic carbonate rock, with intrinsic high porosity and permeability. The freshwater lenses of small islands are dominated by diffuse flow regimes as the island perimeter is everywhere close to the meteoric catchment of the island interior. This flow regime produces flank margin caves at the lens margin, where dissolution is enhanced by mixing corrosion, superposition of organic decay horizons and higher flow velocities as the lens thins. The lens interior develops touching-vug flow systems that result in enhanced permeability and lens thinning over time. As islands become larger, the area (meteoric catchment) goes up by the square, but the island perimeter (discharge zone) goes up linearly; diffuse flow becomes inefficient; conduit flow develops to produce traditional epigenic cave systems that discharge the freshwater lens by specific turbulent flow routes, which in turn are fed by diffuse flow in the island interior. Locally, diffuse flow to the island perimeter continues in coastal proximal areas between major conduit flow routes to produce flank margin caves. The Bahamian Archipelago represents a case history in which tectonics is limited, the rocks are entirely eogenetic and the diffuse to conduit flow transition is demonstrated.
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  • 88
    Publication Date: 2018-06-07
    Description: Geosciences, Vol. 8, Pages 205: Geotourism and Local Development Based on Geological and Mining Sites Utilization, Zaruma-Portovelo, Ecuador Geosciences doi: 10.3390/geosciences8060205 Authors: Paúl Carrión Mero Gricelda Herrera Franco Josué Briones Pablo Caldevilla María José Domínguez-Cuesta Edgar Berrezueta This study offers a detailed assessment of the geosites and mining sites present in the Zaruma-Portovelo mining district (Ecuador) through their qualitative and quantitative assessment. It shows up the potentiality of this area taking advantage of its geological-mining heritage. The methodological process includes: (i) compilation and inventory of all the sites within the study area with particular geological or mining interest; (ii) preparation of reports and thematic cartography, (iii) assessment and classification of the elements of geological-mining interest; (iv) SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis and TOWS (Threats, Opportunities, Weaknesses, Strengths) matrix preparation seeking strategies to guarantee the viability of geotourism. A total of 16 sites of geological interest and 11 of mining interest were identified. The 77% of these sites was proved to be of high and very high interest in scientific terms. Likewise, their susceptibility to degradation assessed from their vulnerability and fragility was found to be high or very high in the 30% of the cases. As for the protection priority, all the studied sites obtained a medium-high result. Finally, the study based on the SWOT-TOWS revealed the possibility of applying action strategies in order to facilitate the compatibility of geotourism with the current productive activities, despite the difficult situation in the study area created by mining activities.
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  • 89
    Publication Date: 2018-06-07
    Description: Geosciences, Vol. 8, Pages 204: Migration and Morphology of Asymmetric Barchans in the Central Hexi Corridor of Northwest China Geosciences doi: 10.3390/geosciences8060204 Authors: Zhengcai Zhang Zhibao Dong Guangyin Hu Eric J. R. Parteli Crescent-shaped barchan dunes often display an asymmetric shape, with one limb longer than the other. As shown in previous studies, asymmetric bimodal winds constitute one major cause of barchan asymmetry, but the heterogeneous conditions of sand availability or flux, as well as topographic influences, may be also important. Understanding the morphology and dynamics of asymmetric barchans may have an impact in a broad range of areas, particularly as these dunes may serve as a proxy for planetary wind regimes and soil conditions in extraterrestrial environments. However, in addition to the existing theories and numerical models that explain barchan asymmetry, direct measurements of migration rates and morphologic changes of real asymmetric barchans over a time span of several years would be beneficial. Therefore, here we report such measurements, which we have acquired by investigating asymmetric barchans in the Hexi Corridor, northwest of China. We have found that dune interactions and asymmetric influx conditions are the most important causes of barchan asymmetry in this field. Particle size distributions in the Hexi Corridor display strong variations over different parts of the asymmetric barchans, as well as over different dunes, with gravel particles being incorporated from the substrate as the dunes migrate. Our observations have shown that upwind sediment sources are important for dune formation in the Hexi Corridor, and that interdune interactions affect dune shape in different ways, depending on their offset. The asymmetric barchans in the Hexi Corridor are active, with an average migration rate (MR) between 8 and 53 m year−1, in spite of the different asymmetric shapes. Our data for dune migration rates can be described well by a scaling of MR = A/(W + W0), where W is the barchan cross-wind width, A ≈ 2835 m2 s−1, and W0 ≈ 44 m. A similar scaling fits very well the migration rate as a function of dune along-wind width L, (i.e., MR = B/(L + L0), with B ≈ 1722 m2 s−1 and L0 ≈ 13 m). Linear relations are also found between both dune widths and the average limb and windward side lengths, thus indicating that the morphometric relations that are predicted from models for steady-state, symmetric crescent-shaped dunes can be applied to different transitional morphologies of interacting, asymmetric barchans.
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  • 90
    Publication Date: 2018-05-29
    Description: Geosciences, Vol. 8, Pages 193: Temperature and Conductivity as Indicators of the Morphology and Activity of a Submarine Volcano: Avyssos (Nisyros) in the South Aegean Sea, Greece Geosciences doi: 10.3390/geosciences8060193 Authors: Evangelos Bakalis Theo Mertzimekis Paraskevi Nomikou Francesco Zerbetto The morphology and the activity of a submarine caldera, Avyssos, at the northern part of Nisyros volcano in the South Aegean Sea (Greece), has been studied by means of remotely-operated underwater vehicle dives. The recorded time series of temperature and conductivity over the submarine volcano have been analyzed in terms of the generalized moments method. The findings of the mathematical analysis shed light on the volcanic activity, but also on the morphology (shape) of the submarine volcano. The conductivity time series indicates that the volcano is at rest, in agreement with other types of observations. On the other hand, temperature fluctuations, which in general describe a multifractal process, show that the submarine caldera operates as an open system that interacts with its surroundings. This type of analysis can be used as an indicator for the state of activity and the morphological structure (closed or open system) of a submarine volcano.
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  • 91
    Publication Date: 2018-05-29
    Description: Geosciences, Vol. 8, Pages 192: Detection of Karst Features in the Black Hills Area in South Dakota/Wyoming, USA, Based on Evaluations of Remote Sensing Data Geosciences doi: 10.3390/geosciences8060192 Authors: Barbara Theilen-Willige Landsat 8, Sentinel 2, Aster, RapidEye and PlanetScope data and Sentinel 1- and Advanced Land Observing Satellite (ALOS)-Phased Array type L-band Synthetic Aperture Radar (PALSAR)-radar images have been evaluated for a karst feature inventory in the Black Hills area in Wyoming/South Dakota, USA. The GeoInformation System (GIS) integrated evaluation of the different satellite data included as well World Imagery files of ESRI and Bing Maps high resolution satellite data of Microsoft. The satellite data revealed several types of circular features related to karst such as enclosed depressions and collapsed dolines as well as traces of tectonic/structural features (visualized by lineament analysis) cutting through youngest sediments, influencing karstification processes. The origin of the circular features is complex and partly unknown, needing further investigations. Digital Elevation Model (DEM) data, such as Aster- and Shuttle Radar Topography Mission (SRTM) DEM data with 30 m and ALOS PASAR DEM with 12.5 m spatial resolution contributed to the detection of depressions, partly related to karst phenomena (sinkholes). Time series of satellite data reveal seasonal changes of the landscape and provide a data base for the documentation of the impact of climate change.
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  • 92
    Publication Date: 2018-06-09
    Description: Geosciences, Vol. 8, Pages 209: Numerical Modeling of Remediation Scenarios of a Groundwater Cr(VI) Plume in an Alpine Valley Aquifer Geosciences doi: 10.3390/geosciences8060209 Authors: Gennaro Stefania Marco Rotiroti Letizia Fumagalli Chiara Zanotti Tullia Bonomi This work presents the numerical modeling of remediation scenarios aimed at containing and attenuating the groundwater pollution by Cr(VI) sourced from a steelworks area that affects the Alpine aquifer system in the Aosta Plain (N Italy). Here, groundwater is used for drinking water supply and food and beverage production, so the adoption of remediation works is urgently needed. More specifically, three remediation scenarios were modeled using MODFLOW-2000 and MT3DMS: (a) the activation of a hydraulic barrier to contain the pollution within the source area (Scenario 1); (b) the removal of the pollution sources and the natural attenuation of the residual groundwater plume (Scenario 2); and (c) a combination of the previous two works (Scenario 3). Model results for Scenario 1 showed that a hydraulic barrier composed of five wells located along the eastern border of the steelworks area would contain Cr(VI) concentrations above 5 µg/L (i.e., the Italian regulatory limit) within the steelworks area; the barrier would have a total discharge of 27,500 m3/day, which could be compensated by the deactivation of three steelworks wells; the hydraulic barrier would drop the Cr(VI) concentrations below 5 µg/L in the areas downstream of the steelworks after ~3 years from its start of operation. Results for Scenario 2 highlighted that the removal of the Cr(VI) sources would drop the Cr(VI) concentrations below 5 µg/L in the areas downstream of the steelworks after ~2.5 years, and lead to a full remediation of the Cr(VI) groundwater plume (i.e., total Cr(VI) mass in the aquifer close to zero) after 17 years. Results for Scenario 3 showed that the removal of the Cr(VI) sources accompanied by the activation of the hydraulic barrier would led to a faster remediation within the first 14 years from the starting of the remediation works, with concentrations below 5 µg/L in the areas downstream of the steelworks obtained after ~2.3 years.
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  • 93
    Publication Date: 2018-06-09
    Description: Geosciences, Vol. 8, Pages 208: Geomorphological Mapping and Spatial Analyses of an Upper Weichselian Glacitectonic Complex Based on LiDAR Data, Jasmund Peninsula (NE Rügen), Germany Geosciences doi: 10.3390/geosciences8060208 Authors: Anna Gehrmann Chris Harding Glacitectonic deformation in the Upper Weichselian led to the tectonic framework of large-scale folds and displaced thrust sheets of Maastrichtian (Upper Cretaceous) chalk and Pleistocene glacial deposits in the southwestern Baltic Sea region. They form surface expressions of sub-parallel ridges and elongated valleys in between and on the Jasmund Peninsula. Geomorphological mapping and detailed landform analyses give another insight into the arrangement and the formation history of these proglacial surface structures. Light detection and ranging (LiDAR) digital elevation models (DEM) analysis techniques were applied to a proglacial rather than a subglacial environment. Results suggest a division into a northern part with morphological ridges striking NW–SE and a southern part with SW–NE trending ridges. The observation of partly truncated northerly ridges and their superimposition by the southern sub-complex suggest that the northern part was generated earlier than the southern part. The applied spatial analyses tools were used to develop a new, self-consistent genetic model integrating all parts of the 100 km2 large Jasmund Glacitectonic Complex. Results suggest a more consistent terminology for the tectonic setting and a revised genetic model for Jasmund, including three evolutional stages that are characterized by different ice flow patterns.
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  • 94
    Publication Date: 2018-06-14
    Description: Geosciences, Vol. 8, Pages 215: Joint and Lineament Patterns across the Midcontinent Indicate Repeated Reactivation of Basement-Involved Faults Geosciences doi: 10.3390/geosciences8060215 Authors: Caroline M. Burberry Jerlyn L. Swiatlowski Mindi L. Searls Irina Filina Joint networks hosted in successively younger rocks, developing as a result of forced (trishear) folding of a rock mass above a deep-seated fault, can be used to infer the reactivation history of that deep-seated fault. This study aims to use joint networks in Pennsylvanian, Permian and Cretaceous rocks to document evidence of reactivation on basement faults during the Paleozoic and Mesozoic of Nebraska and Kansas. The most prominent basement features in southeast Nebraska and northeast Kansas are oriented NE-SW, likely related to the Midcontinent Rift System and Nemaha Uplift, and oriented NW-SE, likely related to fabrics from the Central Plains Orogeny. These features are well defined in the potential fields data. Joint patterns in the study area show an E-W oriented trend, as well as clearly discernable NE-SW and subsidiary N-S and NW-SE trends. The E-W trend is interpreted to be related to far-field stresses from Laramide and Ancestral Rocky Mountain orogenic events, whilst the NE-SW trend is interpreted to be related to subtle reactivation on the Mid-continent rift and related faults, observed in basement data. These movements produced stresses of sufficient magnitude to produce joints in the post-rift rock units, but not sufficient to generate shear fractures. Similarly, the ~N-S and NW-SE joint trends are taken as evidence of subtle reactivation on the Nemaha Uplift and Central Plains Orogeny systems, generating joints by the formation of forced folds. This contribution therefore provides a convincing case study of the value of coupled potential fields and surface feature studies in discerning buried tectonic trends and subtle reactivation thereon.
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  • 95
    Publication Date: 2018-06-16
    Description: Geosciences, Vol. 8, Pages 219: Regional Landslide Potential Mapping in Earthquake-Prone Areas of Kepahiang Regency, Bengkulu Province, Indonesia Geosciences doi: 10.3390/geosciences8060219 Authors: Arif Ismul Hadi Kirbani Sri Brotopuspito Subagyo Pramumijoyo Hary Christady Hardiyatmo Kepahiang regency is an area above the Musi segment of the Sumatran fault system. This condition makes the study area prone to natural disasters such as landslides in the slope area caused by earthquakes due to tectonic plate movement. The objective of this study was to locate potential landslide areas in earthquake-prone areas of Kepahiang regency, Bengkulu province, Indonesia. We performed horizontal to vertical spectral ratio (HVSR) analysis and simple additive weighting (SAW) methods to accomplish the goal. The acquisition of field data involved a broad band seismometer PASI Gemini-2 (triaxial geophone). The microtremor data recorded in the field were then analyzed by the wave spectrum. The results showed that the landslide potential in the study area could be divided into three categories, i.e., low, medium, and high potential. Areas with high potential should be more aware of the threat of landslides, especially in population-dense areas. The greatest threat in the study area is an earthquake along Sumatra’s active fault. An earthquake that occurs in a very steep, landslide-prone area can increase risk and trigger a landslide.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 96
    Publication Date: 2018-06-16
    Description: Geosciences, Vol. 8, Pages 218: Application of Sensitivity Analysis for Process Model Calibration of Natural Hazards Geosciences doi: 10.3390/geosciences8060218 Authors: Candace Chow Jorge Ramirez Margreth Keiler Sensitivity analysis (SA) describes how varying inputs to a model subsequently varies its outputs. Its inclusion can support the systematic calibration of numerical models to back-calculate intensity properties of past torrent events that would otherwise be difficult or impossible to collect during their occurrence. Sensitivity analysis for model calibration is assessed with the back-calculation of a known torrent event. In particular, FLO-2D, a cell-based numerical model, is used to simulate the 2005 debris flow event that occurred in Brienz, Switzerland. Under 4000 simulations were completed with ranges of physically reasonable parameter values. Model results were compared in 3-dimensions with both sediment deposition extents (x, y) and estimated deposition heights (z) from available post-event images. The comparisons highlighted that more accurate input and validation data, namely the flow behavior of hazardous processes and post-event deposition heights, are required to produce stronger agreements between simulated and observed results. Furthermore, the application of SA for model calibration supports systematic exploration of large parameter spaces characteristic of complex phenomena like natural hazard events. These findings demonstrated how important model input factors can be identified, which provide guidance for future data collection efforts to capture both the rheology and the spatial distribution of hazards more accurately.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 97
    Publication Date: 2018-06-17
    Description: Geosciences, Vol. 8, Pages 221: Extending INSPIRE to the Internet of Things through SensorThings API Geosciences doi: 10.3390/geosciences8060221 Authors: Alexander Kotsev Katharina Schleidt Steve Liang Hylke van der Schaaf Tania Khalafbeigi Sylvain Grellet Michael Lutz Simon Jirka Mickaël Beaufils Spatial Data Infrastructures (SDI) established during the past two decades “unlocked” heterogeneous geospatial datasets. The European Union INSPIRE Directive laid down the foundation of a pan-European SDI where thousands of public sector data providers make their data, including sensor observations, available for cross-border and cross-domain reuse. At the same time, SDIs should inevitably adopt new technology and standards to remain fit for purpose and address in the best possible way the needs of different stakeholders (government, businesses and citizens). Some of the recurring technical requirements raised by SDI stakeholders include: (i) the need for adoption of RESTful architectures; together with (ii) alternative (to GML) data encodings, such as JavaScript Object Notation (JSON) and binary exchange formats; and (iii) adoption of asynchronous publish–subscribe-based messaging protocols. The newly established OGC standard SensorThings API is particularly interesting to investigate for INSPIRE, as it addresses together all three topics. In this manuscript, we provide our synthesised perspective on the necessary steps for the OGC SensorThings API standard to be considered as a solution that meets the legal obligations stemming out of the INSPIRE Directive. We share our perspective on what should be done concerning: (i) data encoding; and (ii) the use of SensorThings API as a download service.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 98
    Publication Date: 2018-06-21
    Description: Geosciences, Vol. 8, Pages 225: A Numerical 1.5D Method for the Rapid Simulation of Geophysical Resistivity Measurements Geosciences doi: 10.3390/geosciences8060225 Authors: Mostafa Shahriari Sergio Rojas David Pardo Angel Rodríguez-Rozas Shaaban A. Bakr Victor M. Calo Ignacio Muga In some geological formations, borehole resistivity measurements can be simulated using a sequence of 1D models. By considering a 1D layered media, we can reduce the dimensionality of the problem from 3D to 1.5D via a Hankel transform. The resulting formulation is often solved via a semi-analytic method, mainly due to its high performance. However, semi-analytic methods have important limitations such as, for example, their inability to model piecewise linear variations on the resistivity. Herein, we develop a multi-scale finite element method (FEM) to solve the secondary field formulation. This numerical scheme overcomes the limitations of semi-analytic methods while still delivering high performance. We illustrate the performance of the method with numerical synthetic examples based on two symmetric logging-while-drilling (LWD) induction devices operating at 2 MHz and 500 KHz, respectively.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 99
    Publication Date: 2018-06-23
    Description: Geosciences, Vol. 8, Pages 230: Rehabilitation of Aging Urban Water Systems: Strategic Thinking Required Geosciences doi: 10.3390/geosciences8070230 Authors: Tapio S. Katko Jarmo J. Hukka Petri S. Juuti Riikka P. Rajala This paper highlights the fundamental and invaluable role of water services in human settlements and community development. The paper aims at revealing the reasons behind aging infrastructure, the major challenge of the sector worldwide, and finding alternative strategies and means for resolving them. The authors argue that the problems of water services are largely related to management, institutions, organizations, and policies. In many ways, the requirement to see water services in a wider institutional framework is analogical to the proposed framework of Integrated Urban Water Management. The paper first explores the exceptionally long timeframe of water services management, followed by frameworks on core and non-core operations of water utilities in relation to the roles of major parties in municipal decision-making. For solving the major problems of water services both political and professional will is needed, educational programs are to be revised, and better rules of the game (institutions) are needed together with additional inputs on Research and Development activities.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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  • 100
    Publication Date: 2018-06-27
    Description: Geosciences, Vol. 8, Pages 234: Geotourism: A Systematic Literature Review Geosciences doi: 10.3390/geosciences8070234 Authors: Rannveig Ólafsdóttir Edita Tverijonaite Geotourism is one of the newest concepts within tourism studies today. The popularity of geotourism has likewise grown rapidly over the past few decades. This rapidly growing popularity and the growing body of research on geotourism create the need for a comprehensive review of existing literature on the subject. The present study aims to systematically review scientific literature on geotourism published over the past two decades by identifying what knowledge has been produced on geotourism in the scientific literature and by analyzing the evolving research trends in geotourism during the same time period. The results reveal that researchers are placing an increasing focus on geotourism. A geographical analysis of the study areas indicates a true global distribution, encompassing studies of 53 countries altogether. Most of the research focusses on identifying, describing, and assessing the geoheritage of the areas in question together with their geotourism potential. The volume of research on these topics is growing at a rapid pace. Other common research topics as regards geotourism include management of geotourism and geoheritage, new geosite/geomorphosite assessment models, together with other methodological approaches. The results further indicate that researchers are less interested in geotourism stakeholders such as tourists and local communities, and that only a very small number of studies examine geotourism in the context of sustainable development. The vast majority of the studies utilize empirical data as the basis of the research or for the testing of proposed models and methodology. The present review identifies a need for a larger body of empirical research focusing on sustainability of geotourism (including actual impacts of geotourism on the geoheritage, the ecosystems and wildlife of geotourism areas), stakeholders and their complex interrelations, knowledge on effective management of the main challenges of geotourism, and the effects of geotourism on local communities and their well-being.
    Electronic ISSN: 2076-3263
    Topics: Geosciences
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