Geosciences

22 pages, 25554 KiB

Open AccessEditor’s ChoiceArticle

Geological and Structural Control on Localized Ground Effects within the Heunghae Basin during the Pohang Earthquake (M_W 5.4, 15th November 2017), South Korea

by Sambit Prasanajit Naik, Young-Seog Kim, Taehyung Kim and Jeong Su-Ho

Geosciences 2019, 9(4), 173; https://doi.org/10.3390/geosciences9040173 - 16 Apr 2019

Cited by 25 | Viewed by 7228

Abstract

On 15th November 2017, the Pohang earthquake (M_w 5.4) had strong ground shaking that caused severe liquefaction and lateral spreading across the Heunghae Basin, around Pohang city, South Korea. Such liquefaction is a rare phenomenon during small or moderate earthquakes (M_W [...] Read more.

On 15th November 2017, the Pohang earthquake (M_w 5.4) had strong ground shaking that caused severe liquefaction and lateral spreading across the Heunghae Basin, around Pohang city, South Korea. Such liquefaction is a rare phenomenon during small or moderate earthquakes (M_W < 5.5). There are only a few examples around the globe, but more so in the Korean Peninsula. In this paper, we present the results of a systematic survey of the secondary ground effects—i.e., soil liquefaction and ground cracks—developed during the earthquake. Most of the liquefaction sites are clustered near the epicenter and close to the Heunghae fault. Based on the geology, tectonic setting, distribution, and clustering of the sand boils along the southern part of the Heunghae Basin, we propose a geological model, suggesting that the Heunghae fault may have acted as a barrier to the propagation of seismic waves. Other factors like the mountain basin effect and/or amplification of seismic waves by a blind thrust fault could play an important role. Liquefaction phenomenon associated with the 2017 Pohang earthquake emphasizes that there is an urgent need of liquefaction potential mapping for the Pohang city and other areas with a similar geological setting. In areas underlain by extensive unconsolidated basin fill sediments—where the records of past earthquakes are exiguous or indistinct and there is poor implementation of building codes—future earthquakes of similar or larger magnitude as the Pohang earthquake are likely to occur again. Therefore, this represents a hazard that may cause significant societal and economic threats in the future. Full article

(This article belongs to the Special Issue New Perspectives in the Definition/Evaluation of Seismic Hazard through Analysis of the Environmental Effects Induced by Earthquakes)

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24 pages, 21882 KiB

Open AccessEditor’s ChoiceArticle

A Detailed Reconstruction of the Roman Landscape and the Submerged Archaeological Structure at “Castel dell’Ovo islet” (Naples, Southern Italy)

by Gerardo Pappone, Pietro P.C. Aucelli, Gaia Mattei, Francesco Peluso, Michele Stefanile and Armando Carola

Geosciences 2019, 9(4), 170; https://doi.org/10.3390/geosciences9040170 - 13 Apr 2019

Cited by 27 | Viewed by 4315

Abstract

In this paper, we present the results of a multidisciplinary study aimed to reconstruct the Roman coastal landscape between Pizzofalcone hill and Megaris islet—the area of the ancient Parthenope, the first settlement along the Naples coast. This coastal sector was surveyed by a [...] Read more.

In this paper, we present the results of a multidisciplinary study aimed to reconstruct the Roman coastal landscape between Pizzofalcone hill and Megaris islet—the area of the ancient Parthenope, the first settlement along the Naples coast. This coastal sector was surveyed by a team of specialized divers (archaeologists and geomorphologists) and by using an Unmanned Surface Vessel (USV) equipped with acoustic and optical sensors. The indirect surveys provided a high-resolution dataset of morpho-acoustic and optical measurements, useful to obtain the geological, geomorphological and archaeological interpretations necessary to formulate hypotheses on the functionality of the complex submerged archaeological structure detected in the study area. In particular, the integration between the surveyed data, the high-resolution seafloor mapping and the previous knowledge deriving from the 1980s underwater research carried out by Centro Studi Subacquei, led us to interpret the submerged remains as a vivarium related to a 1st century BC Roman villa. Finally, by measuring the submersion of several channels and a well-preserved crepido, a relative sea level during the period of use at −2.2 m ± 0.2 m mean sea level (MSL) was deduced, in agreement with the previous geoarchaeological studies realized in the near coastal sectors. Full article

(This article belongs to the Special Issue Geoarchaeology: A Review of Case Studies in the Mediterranean Sea)

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20 pages, 9394 KiB

Open AccessEditor’s ChoiceArticle

Spatial and Temporal Variations in the Incidence of Dust Storms in Saudi Arabia Revealed from In Situ Observations

by Sarah Albugami, Steven Palmer, Jonathan Cinnamon and Jeroen Meersmans

Geosciences 2019, 9(4), 162; https://doi.org/10.3390/geosciences9040162 - 8 Apr 2019

Cited by 43 | Viewed by 8873

Abstract

Monthly meteorological data from 27 observation stations provided by the Presidency of Meteorology and Environment (PME) of Saudi Arabia were used to analyze the spatial and temporal distribution of atmospheric dust in Saudi Arabia between 2000 and 2016. These data were used to [...] Read more.

Monthly meteorological data from 27 observation stations provided by the Presidency of Meteorology and Environment (PME) of Saudi Arabia were used to analyze the spatial and temporal distribution of atmospheric dust in Saudi Arabia between 2000 and 2016. These data were used to analyze the effects of environmental forcing on the occurrence of dust storms across Saudi Arabia by considering the relationships between dust storm frequency and temperature, precipitation, and wind variables. We reveal a clear seasonality in the reported incidence of dust storms, with the highest frequency of events during the spring. Our results show significant positive relationships (p < 0.005) between dust storm occurrence and wind speed, wind direction, and precipitation. However, we did not detect a significant relationship with temperature. Our results reveal important spatial patterns, as well as seasonal and inter-annual variations, in the occurrence of dust storms in Saudi Arabia. For instance, the eastern part of the study area experienced an increase in dust storm events over time, especially in the region near Al-Ahsa. Similarly, an increasing trend in dust storms was also observed in the west of the study area near Jeddah. However, the occurrence of dust storm events is decreasing over time in the north, in areas such as Hail and Qaisumah. Overall, the eastern part of Saudi Arabia experiences the highest number of dust storms per year (i.e., 10 to 60 events), followed by the northern region, with the south and the west having fewer dust storm events (i.e., five to 15 events per year). In addition, our results showed that the wind speeds during a dust storm are 15–20 m/s and above, while, on a non-dust day, the wind speeds are approximately 10–15 m/s or lower. Findings of this study provide insight into the relationship between environmental conditions and dust storm occurrence across Saudi Arabia, and a basis for future research into the drivers behind these observed spatio-temporal trends. Full article

(This article belongs to the Special Issue Observing Atmospheric Dynamics and Dust Activity)

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18 pages, 5357 KiB

Open AccessEditor’s ChoiceArticle

A Hybrid Spatial Multi-Criteria Evaluation Method for Mapping Landslide Susceptible Areas in Kullu Valley, Himalayas

by Sansar Raj Meena, Brijendra Kumar Mishra and Sepideh Tavakkoli Piralilou

Geosciences 2019, 9(4), 156; https://doi.org/10.3390/geosciences9040156 - 3 Apr 2019

Cited by 38 | Viewed by 5569

Abstract

In this paper we report our results from analysing a hybrid spatial multi-criteria evaluation (SMCE) method for generating landslide susceptibility mapping (LSM). This study is the first of its kind in the Kullu valley, Himalayas. We used eight related geospatial conditioning factors from [...] Read more.

In this paper we report our results from analysing a hybrid spatial multi-criteria evaluation (SMCE) method for generating landslide susceptibility mapping (LSM). This study is the first of its kind in the Kullu valley, Himalayas. We used eight related geospatial conditioning factors from three main groups: geological, morphological and topographical factors. Our landslide inventory dataset has a total of 149 GPS points of landslide locations, collected based on a field survey in July 2018. The relationships between landslide locations and conditioning factors were determined using the GIS-based statistical methods of frequency ratio (FR), multi-criteria decision-making (MCDM) and the integration method of hybrid SMCE. We compared the performance of applied methods by dividing the inventory into testing (70%) and validation (30%) datasets. The area under the curve (AUC) was used to validate the results. The integration method of hybrid SMCE gave the highest accuracy rate (0.910) compared to the other two methods, with 0.797 and 0.907 accuracy rates for the analytical hierarchy process (AHP) and FR, respectively. The applied methodologies are easily transferable to other areas, and the resulting landslide susceptibility maps (LSMs) can be useful for risk mitigation and development planning purposes in the Kullu valley, Himalayas. Full article

(This article belongs to the Section Natural Hazards)

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15 pages, 237 KiB

Open AccessEditor’s ChoiceReview

Satellite SAR Data-based Sea Ice Classification: An Overview

by Natalia Zakhvatkina, Vladimir Smirnov and Irina Bychkova

Geosciences 2019, 9(4), 152; https://doi.org/10.3390/geosciences9040152 - 31 Mar 2019

Cited by 103 | Viewed by 9755

Abstract

A review of the main approaches developed for sea ice classification using satellite imagery is presented. Satellite data are the main and very often only information source for sea ice classification and charting in the remote arctic regions. The main techniques used for [...] Read more.

A review of the main approaches developed for sea ice classification using satellite imagery is presented. Satellite data are the main and very often only information source for sea ice classification and charting in the remote arctic regions. The main techniques used for ice classification and ice charting in several national ice services are considered. Advantages and disadvantages of various SAR data-based methods for ice classification are analyzed. It is shown that an increase of SAR technical abilities contributes to the enhancement of sea ice classification reliability. The possible further development of satellite data-based methods for ice classification is discussed. Full article

(This article belongs to the Special Issue Cryosphere II)

19 pages, 2841 KiB

Open AccessEditor’s ChoiceArticle

Estimation of Soil Erosion in Nepal Using a RUSLE Modeling and Geospatial Tool

by Pooja Koirala, Sudeep Thakuri, Subesh Joshi and Raju Chauhan

Geosciences 2019, 9(4), 147; https://doi.org/10.3390/geosciences9040147 - 29 Mar 2019

Cited by 150 | Viewed by 19868

Abstract

Soil erosion is a major issue, causing the loss of topsoil and fertility in agricultural land in mountainous terrain. Estimation of soil erosion in Nepal is essential because of its agriculture-dependent economy (contributing 36% to national GDP) and for preparing erosion control plans. [...] Read more.

Soil erosion is a major issue, causing the loss of topsoil and fertility in agricultural land in mountainous terrain. Estimation of soil erosion in Nepal is essential because of its agriculture-dependent economy (contributing 36% to national GDP) and for preparing erosion control plans. The present study, for the first time, attempts to estimate the soil loss of Nepal through the application of the Revised Universal Soil Loss Equation (RUSLE) model. In addition, it analyzes the effect of Land Use and Land Cover (LULC) and slope (

β)

exposition on soil erosion. Nation-wide mean annual soil loss of Nepal is estimated at 25 t ha⁻¹ yr⁻¹ with a total of 369 million tonnes (mT) of potential soil loss. Soil erosion based on the physiographic region of the country shows that the Middle Mountains, High Mountains, High Himal, Chure, and Terai have mean erosion rates of 38.0, 32.0, 28.0, 7.0, and 0.1 t ha⁻¹ yr⁻¹. The soil erosion rate by basins showed that the annual erosions of the Karnali, Gandaki, Koshi, and Mahakali River basins are 135, 96, 79, and 15 mT, respectively. The mean soil erosion rate was significantly high (34 t ha⁻¹ yr⁻¹) for steep slopes (β > 26.8%) and the low (3 t ha⁻¹ yr⁻¹) for gentle slopes (β < 5%). Based on LULC, the mean erosion rate for barren land was the highest (40 t ha⁻¹ yr⁻¹), followed by agricultural land (29 t ha⁻¹ yr⁻¹), shrubland (25 t ha⁻¹ yr⁻¹), grassland (23 t ha⁻¹ yr⁻¹), and forests (22 t ha⁻¹ yr⁻¹). The entire area had been categorized into 6 erosion classes based on the erosion severity, and 11% of the area was found to be under a very severe erosion risk (> 80 t ha⁻¹ yr⁻¹) that urgently required reducing the risk of erosion. Full article

(This article belongs to the Special Issue Soil Hydrology and Erosion)

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11 pages, 2537 KiB

Open AccessEditor’s ChoiceArticle

Geo-Heritage Specific Visibility as an Important Parameter in Geo-Tourism Resource Evaluation

by Anna V. Mikhailenko and Dmitry A. Ruban

Geosciences 2019, 9(4), 146; https://doi.org/10.3390/geosciences9040146 - 27 Mar 2019

Cited by 32 | Viewed by 4679

Abstract

Geological heritage (geo-heritage) is a resource for geoscience, geo-education, and geo-tourism. Geo-tourist attractions differ in their physical visibility, interpretation (clarity), and aesthetic attractiveness. These three characteristics determine perception of visitors and, thus, the importance of attractions. An integrative parameter, namely specific visibility, is [...] Read more.

Geological heritage (geo-heritage) is a resource for geoscience, geo-education, and geo-tourism. Geo-tourist attractions differ in their physical visibility, interpretation (clarity), and aesthetic attractiveness. These three characteristics determine perception of visitors and, thus, the importance of attractions. An integrative parameter, namely specific visibility, is proposed for qualitative geo-tourism resource evaluation. This parameter is examined for all geo-heritage types, and some relevant examples from southwest Russia are considered. The geo-heritage types differ in their specific visibility. For instance, when landforms like the Granite Gorge in the Western Caucasus (geomorphological type) are well-visible, geochemical processes like the heavy metal cycling in the Don River delta and the Pelenkino mud lake (geo-chemical type) are not as visible. Such a difference should be taken into account when geo-tourism resources of any area or a geopark are evaluated. The lower the specific visibility, the higher the costs for professional interpretation and demand for advanced infrastructure solutions. Full article

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19 pages, 8012 KiB

Open AccessEditor’s ChoiceArticle

Multispectral Multibeam Echo Sounder Backscatter as a Tool for Improved Seafloor Characterization

by Craig J. Brown, Jonathan Beaudoin, Mike Brissette and Vicki Gazzola

Geosciences 2019, 9(3), 126; https://doi.org/10.3390/geosciences9030126 - 12 Mar 2019

Cited by 71 | Viewed by 13043

Abstract

The establishment of multibeam echosounders (MBES), as a mainstream tool in ocean mapping, has facilitated integrative approaches towards nautical charting, benthic habitat mapping, and seafloor geotechnical surveys. The combined acoustic response of the seabed and the subsurface can vary with MBES operating frequency. [...] Read more.

The establishment of multibeam echosounders (MBES), as a mainstream tool in ocean mapping, has facilitated integrative approaches towards nautical charting, benthic habitat mapping, and seafloor geotechnical surveys. The combined acoustic response of the seabed and the subsurface can vary with MBES operating frequency. At worst, this can make for difficulties in merging the results from different mapping systems or mapping campaigns. However, at best, having observations of the same seafloor at different acoustic wavelengths allows for increased discriminatory power in seabed classification and characterization efforts. Here, we present the results from trials of a multispectral multibeam system (R2Sonic 2026 MBES, manufactured by R2Sonic, LLC, Austin, TX, USA) in the Bedford Basin, Nova Scotia. In this system, the frequency can be modified on a ping-by-ping basis, which can provide multi-spectral acoustic measurements with a single pass of the survey platform. The surveys were conducted at three operating frequencies (100, 200, and 400 kHz), and the resulting backscatter mosaics revealed differences in parts of the survey area between the frequencies. Ground validation surveys using a combination of underwater video transects and benthic grab and core sampling confirmed that these differences were due to coarse, dredge spoil material underlying a surface cover of mud. These innovations offer tremendous potential for application in the area of seafloor geological and benthic habitat mapping. Full article

(This article belongs to the Special Issue Geological Seafloor Mapping)

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31 pages, 37496 KiB

Open AccessEditor’s ChoiceArticle

Morphostructural, Meteorological and Seismic Factors Controlling Landslides in Weak Rocks: The Case Studies of Castelnuovo and Ponzano (North East Abruzzo, Central Italy)

by Monia Calista, Enrico Miccadei, Tommaso Piacentini and Nicola Sciarra

Geosciences 2019, 9(3), 122; https://doi.org/10.3390/geosciences9030122 - 9 Mar 2019

Cited by 28 | Viewed by 6836

Abstract

We investigated the role of the morphostructural setting and seismic and meteorological factors in the development of landslides in the piedmont of the Abruzzo Apennines. In February 2017, following a heavy snow precipitation event and a moderate seismic sequence (at the end of [...] Read more.

We investigated the role of the morphostructural setting and seismic and meteorological factors in the development of landslides in the piedmont of the Abruzzo Apennines. In February 2017, following a heavy snow precipitation event and a moderate seismic sequence (at the end of the Central Italy 2016–2017 seismic crisis), several landslides affected the NE-Abruzzo chain and piedmont area. This work is focused on the Ponzano landslide (Civitella del Tronto, Teramo) and the Castelnuovo landslide (Campli, Teramo) in the NE Abruzzo hilly piedmont. These landslides consist of: (1) a large translational slide-complex landslide, affecting the Miocene–Pliocene sandstone clay bedrock sequence of the piedmont hilly sector; and (2) a complex (topple/fall-slide) landslide, which occurred along a high and steep scarp on conglomerate rocks pertaining to terraced alluvial fan deposits of the Pleistocene superficial deposits. Both of the landslides are typical of the Abruzzo hilly piedmont and both of them largely affected houses and villages located on top of the scarp or within the slope. The landslides were studied by means of field geological and geomorphological mapping, borehole investigations, geostructural analysis and photogeological analysis. For the Ponzano landslide, a detail pre-post-landslide air photo interpretation allowed for defining the deformation pattern occurred on the slope. For the Castelnuovo landslide, the triggering factors and the stability of the slope were evaluated with FLAC3D numerical modelling, in pre- and post-landslide conditions. Through this integrated analysis, the triggering factors, the landslide mechanism and the stability conditions of the landslides and the characterization of two main types of landslides affecting the piedmont hilly area of the Abruzzo region were investigated. Full article

(This article belongs to the Special Issue Mountain Landslides: Monitoring, Modeling, and Mitigation)

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41 pages, 1522 KiB

Open AccessEditor’s ChoiceReview

Heavy Metal Rules. I. Exoplanet Incidence and Metallicity

by Vardan Adibekyan

Geosciences 2019, 9(3), 105; https://doi.org/10.3390/geosciences9030105 - 27 Feb 2019

Cited by 59 | Viewed by 7578

Abstract

The discovery of only a handful of exoplanets required establishing a correlation between giant planet occurrence and metallicity of their host stars. More than 20 years have already passed from that discovery, however, many questions are still under lively debate: (1) What is [...] Read more.

The discovery of only a handful of exoplanets required establishing a correlation between giant planet occurrence and metallicity of their host stars. More than 20 years have already passed from that discovery, however, many questions are still under lively debate: (1) What is the origin of that relation?; (2) What is the exact functional form of the giant planet–metallicity relation (in the metal-poor regime)?; and (3) Does such a relation exist for terrestrial planets? All of these questions are very important for our understanding of the formation and evolution of (exo)planets of different types around different types of stars and are the subject of the present manuscript. Besides making a comprehensive literature review about the role of metallicity on the formation of exoplanets, I also revisited most of the planet–metallicity related correlations reported in the literature using a large and homogeneous data provided by the SWEET-Cat catalog. This study led to several new results and conclusions, two of which I believe deserve to be highlighted in the abstract: (i) the hosts of sub-Jupiter mass planets (∼0.6–0.9 M_♃) are systematically less metallic than the hosts of Jupiter-mass planets. This result might be related to the longer disk lifetime and the higher amount of planet building materials available at high metallicities, which allow a formation of more massive Jupiter-like planets; (ii) contrary to the previous claims, our data and results do not support the existence of a breakpoint planetary mass at 4 M_♃ above and below which planet formation channels are different. However, the results also suggest that planets of the same (high) mass can be formed through different channels depending on the (disk) stellar mass i.e., environmental conditions. Full article

(This article belongs to the Special Issue Detection and Characterization of Extrasolar Planets)

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37 pages, 8750 KiB

Open AccessEditor’s ChoiceReview

Marine Geohazards: A Bibliometric-Based Review

by João M. R. Camargo, Marcos V. B. Silva, Antônio V. Ferreira Júnior and Tereza C. M. Araújo

Geosciences 2019, 9(2), 100; https://doi.org/10.3390/geosciences9020100 - 21 Feb 2019

Cited by 34 | Viewed by 9402

Abstract

Marine geohazard research has developed during recent decades, as human activities intensified towards deeper waters. Some recent disastrous events (e.g., the 2004 Indian Ocean and 2011 Japan tsunamis) highlighted geohazards socioeconomic impacts. Marine geohazards encompass an extensive list of features, processes, and events [...] Read more.

Marine geohazard research has developed during recent decades, as human activities intensified towards deeper waters. Some recent disastrous events (e.g., the 2004 Indian Ocean and 2011 Japan tsunamis) highlighted geohazards socioeconomic impacts. Marine geohazards encompass an extensive list of features, processes, and events related to Marine Geology. In the scientific literature there are few systematic reviews concerning all of them. Using the search string ‘geohazard*’, this bibliometric-based review explored the scientific databases Web of Science and Scopus to analyze the evolution of peer-reviewed scientific publications and discuss trends and future challenges. The results revealed qualitative and quantitative aspects of 183 publications and indicated 12 categories of hazards, the categories more studied and the scientific advances. Interdisciplinary surveys focusing on the mapping and dating of past events, and the determination of triggers, frequencies, and current perspectives of occurrence (risk) are still scarce. Throughout the upcoming decade, the expansion and improvement of seafloor observatories’ networks, early warning systems, and mitigation plans are the main challenges. Hazardous marine geological events may occur at any time and the scientific community, marine industry, and governmental agencies must cooperate to better understand and monitor the processes involved in order to mitigate the resulting unpredictable damages. Full article

(This article belongs to the Special Issue Marine Geohazards: New Insights and Perspectives)

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20 pages, 5902 KiB

Open AccessEditor’s ChoiceBenchmark

Signal Processing of GPR Data for Road Surveys

by Luca Bianchini Ciampoli, Fabio Tosti, Nikos Economou and Francesco Benedetto

Geosciences 2019, 9(2), 96; https://doi.org/10.3390/geosciences9020096 - 19 Feb 2019

Cited by 92 | Viewed by 10605

Abstract

Effective quality assurance and quality control inspections of new roads as well as assessment of remaining service-life of existing assets is taking priority nowadays. Within this context, use of ground penetrating radar (GPR) is well-established in the field, although standards for a correct [...] Read more.

Effective quality assurance and quality control inspections of new roads as well as assessment of remaining service-life of existing assets is taking priority nowadays. Within this context, use of ground penetrating radar (GPR) is well-established in the field, although standards for a correct management of datasets collected on roads are still missing. This paper reports a signal processing method for data acquired on flexible pavements using GPR. To demonstrate the viability of the method, a dataset collected on a real-life flexible pavement was used for processing purposes. An overview of the use of non-destructive testing (NDT) methods in the field, including GPR, is first given. A multi-stage method is then presented including: (i) raw signal correction; (ii) removal of lower frequency harmonics; (iii) removal of antenna ringing; (iv) signal gain; and (v) band-pass filtering. Use of special processing steps such as vertical resolution enhancement, migration and time-to-depth conversion are finally discussed. Key considerations about the effects of each step are given by way of comparison between processed and unprocessed radargrams. Results have proven the viability of the proposed method and provided recommendations on use of specific processing stages depending on survey requirements and quality of the raw dataset. Full article

(This article belongs to the Special Issue Advances in Ground Penetrating Radar Research)

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44 pages, 3862 KiB

Open AccessEditor’s ChoiceReview

Gadolinium as an Emerging Microcontaminant in Water Resources: Threats and Opportunities

by Pooria Ebrahimi and Maurizio Barbieri

Geosciences 2019, 9(2), 93; https://doi.org/10.3390/geosciences9020093 - 17 Feb 2019

Cited by 83 | Viewed by 12597

Abstract

As a result of high doses of paramagnetic gadolinium (Gd) chelates administered in magnetic resonance imaging (MRI) exams, their unmetabolized excretion, and insufficient removal in wastewater treatment plants (WWTPs), large amounts of anthropogenic Gd (Gd_anth) are released into surface water. The [...] Read more.

As a result of high doses of paramagnetic gadolinium (Gd) chelates administered in magnetic resonance imaging (MRI) exams, their unmetabolized excretion, and insufficient removal in wastewater treatment plants (WWTPs), large amounts of anthropogenic Gd (Gd_anth) are released into surface water. The upward trend of gadolinium-based contrast agent (Gd-CA) administrations is expected to continue growing and consequently higher and higher anthropogenic Gd concentrations are annually recorded in water resources, which can pose a great threat to aquatic organisms and human beings. In addition, the feasibility of Gd retention in patients administered with Gd-CAs repeatedly, and even potentially fatal diseases, including nephrogenic systemic fibrosis (NSF), due to trace amounts of Gd have recently arisen severe health concerns. Thus, there is a need to investigate probable adverse health effects of currently marketed Gd-CAs meticulously and to modify the actual approach in using Gd contrast media in daily practice in order to minimize unknown possible health risks. Furthermore, the employment of enhanced wastewater treatment processes that are capable of removing the stable contrast agents, and the evaluation of the ecotoxicity of Gd chelates and human exposure to these emerging contaminants through dermal and ingestion pathways deserve more attention. On the other hand, point source releases of anthropogenic Gd into the aquatic environment presents the opportunity to assess surface water—groundwater interactions and trace the fate of wastewater plume as a proxy for the potential presence of other microcontaminants associated with treated wastewater in freshwater and marine systems. Full article

(This article belongs to the Special Issue Emerging contaminants (ECs) in Groundwater)

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18 pages, 4998 KiB

Open AccessEditor’s ChoiceArticle

Picking Up the Pieces—Harmonising and Collating Seabed Substrate Data for European Maritime Areas

by Anu Marii Kaskela, Aarno Tapio Kotilainen, Ulla Alanen, Rhys Cooper, Sophie Green, Janine Guinan, Sytze van Heteren, Susanna Kihlman, Vera Van Lancker, Alan Stevenson and the EMODnet Geology Partners

Geosciences 2019, 9(2), 84; https://doi.org/10.3390/geosciences9020084 - 13 Feb 2019

Cited by 30 | Viewed by 6777

Abstract

The poor access to data on the marine environment is a handicap to government decision-making, a barrier to scientific understanding and an obstacle to economic growth. In this light, the European Commission initiated the European Marine Observation and Data Network (EMODnet) in 2009 [...] Read more.

The poor access to data on the marine environment is a handicap to government decision-making, a barrier to scientific understanding and an obstacle to economic growth. In this light, the European Commission initiated the European Marine Observation and Data Network (EMODnet) in 2009 to assemble and disseminate hitherto dispersed marine data. In the ten years since then, EMODnet has become a key producer of publicly available, harmonised datasets covering broad areas. This paper describes the methodologies applied in EMODnet Geology project to produce fully populated GIS layers of seabed substrate distribution for the European marine areas. We describe steps involved in translating national seabed substrate data, conforming to various standards, into a uniform EMODnet substrate classification scheme (i.e., the Folk sediment classification). Rock and boulders form an additional substrate class. Seabed substrate data products at scales of 1:250,000 and 1:1 million, compiled using descriptions and analyses of seabed samples as well as interpreted acoustic images, cover about 20% and 65% of the European maritime areas, respectively. A simple confidence assessment, based on sample and acoustic coverage, is helpful in identifying data gaps. The harmonised seabed substrate maps are particularly useful in supraregional, transnational and pan-European marine spatial planning. Full article

(This article belongs to the Special Issue Geological Seafloor Mapping)

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14 pages, 5319 KiB

Open AccessEditor’s ChoiceArticle

Down-Sampling of Point Clouds for the Technical Diagnostics of Buildings and Structures

by Czesław Suchocki and Wioleta Błaszczak-Bąk

Geosciences 2019, 9(2), 70; https://doi.org/10.3390/geosciences9020070 - 30 Jan 2019

Cited by 34 | Viewed by 4703

Abstract

Terrestrial laser scanning (TLS) is a non-destructive testing method for the technical assessment of existing structures. TLS has been successfully harnessed for monitoring technical surface conditions and morphological characteristics of historical buildings (e.g., the detection of cracks and cavities). TLS measurements with very [...] Read more.

Terrestrial laser scanning (TLS) is a non-destructive testing method for the technical assessment of existing structures. TLS has been successfully harnessed for monitoring technical surface conditions and morphological characteristics of historical buildings (e.g., the detection of cracks and cavities). TLS measurements with very high resolution should be taken to detect minor defects on the walls of buildings. High-resolution measurements are mostly needed in certain areas of interest, e.g., cracks and cavities. Therefore, reducing redundant information on flat areas without cracks and cavities is very important. In this case, automatic down-sampling of datasets according to the aforementioned criterion is required. This paper presents the use of the Optimum Dataset (OptD) method to optimize TLS dataset. A Leica ScanStation C10 time-of-flight scanner and a Z+F IMAGER 5016 phase-shift scanner were used during the research. The research was conducted on a specially prepared concrete sample and real object, i.e., a brick citadel located on the Kościuszko Mound in Cracow. The reduction of dataset by the OptD method and random method from TLS measurements were compared and discussed. The results prove that the large datasets from TLS diagnostic measurements of buildings and structures can be successfully optimized using the OptD method. Full article

(This article belongs to the Special Issue Geodesy and Geomatics Engineering)

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21 pages, 15083 KiB

Open AccessEditor’s ChoiceArticle

Geo-Hazard-Based Approach for the Estimation of Seismic Vulnerability and Damage Scenarios of the Old City of Senerchia (Avellino, Italy)

by Nicola Chieffo and Antonio Formisano

Geosciences 2019, 9(2), 59; https://doi.org/10.3390/geosciences9020059 - 26 Jan 2019

Cited by 43 | Viewed by 4465

Abstract

The large-scale seismic risk assessment is a crucial point for safeguarding people and planning adequate mitigation plans in urban areas. The current research work aims at analysing a sector of the historic centre of Senerchia, located in the province of Avellino, in order [...] Read more.

The large-scale seismic risk assessment is a crucial point for safeguarding people and planning adequate mitigation plans in urban areas. The current research work aims at analysing a sector of the historic centre of Senerchia, located in the province of Avellino, in order to assess the seismic vulnerability and damage of old masonry building compounds. First, the typological classification of the inspected building aggregates is developed using the CARTIS form developed by the PLINIVS research centre in collaboration with the Italian Civil Protection Department. The global seismic vulnerability assessment of the building sample is carried out using the macroseismic method according to the EMS-98 scale in order to identify the buildings most susceptible to seismic damage. Furthermore, 12 damage scenarios are developed by means of an appropriate seismic attenuation law. Finally, the expected damage scenarios considering the local hazard effects induced are developed in order to evaluate the damage increment, averagely equal to 50%, due to the seismic amplification of different soil categories. Full article

(This article belongs to the Special Issue Inaugural Section Special Issue: Key Topics and Future Perspectives in Natural Hazards Research)

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21 pages, 1998 KiB

Open AccessEditor’s ChoiceArticle

Climate Change-Induced Migration in Coastal Bangladesh? A Critical Assessment of Migration Drivers in Rural Households under Economic and Environmental Stress

by Amelie Bernzen, J. Craig Jenkins and Boris Braun

Geosciences 2019, 9(1), 51; https://doi.org/10.3390/geosciences9010051 - 18 Jan 2019

Cited by 72 | Viewed by 13682

Abstract

Discussions of climate migration have recognized the need for probabilistic, systematic, and empirical analyses. We examine the importance of environmental stressors in migration using a multi-leveled analysis of a household survey of the climate-stressed rural communities of coastal Bangladesh. We find that a [...] Read more.

Discussions of climate migration have recognized the need for probabilistic, systematic, and empirical analyses. We examine the importance of environmental stressors in migration using a multi-leveled analysis of a household survey of the climate-stressed rural communities of coastal Bangladesh. We find that a relatively small share (6.5%) of rural coastal people have migrated, overwhelmingly domestically and on a temporary basis. The main motives are better employment opportunities in urban areas, marriage/family reunification, and education. About a third are displaced by flooding that created loss of arable land. Being male, younger, and working outside of agriculture facilitate migration, and also those with greater human and horizontal social capital are more likely to migrate. Exposure to severe river erosion, residing closer to major waterways and in saltwater shrimp farming zones spur migration. Climate migration is in its first instance economic-induced with environmental stress contributing as a secondary factor. Full article

(This article belongs to the Section Natural Hazards)

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26 pages, 10657 KiB

Open AccessEditor’s ChoiceArticle

Use of Geogrids and Recycled Rubber in Railroad Infrastructure for Enhanced Performance

by Buddhima Indraratna, Yujie Qi, Trung Ngoc Ngo, Cholachat Rujikiatkamjorn, Tim Neville, Fernanda Bessa Ferreira and Amir Shahkolahi

Geosciences 2019, 9(1), 30; https://doi.org/10.3390/geosciences9010030 - 8 Jan 2019

Cited by 41 | Viewed by 5519

Abstract

Railway tracks are conventionally built on compacted ballast and structural fill layers placed above the natural (subgrade) foundation. However, during train operations, track deteriorations occur progressively due to ballast degradation. The associated track deformation is usually accompanied by a reduction in both load [...] Read more.

Railway tracks are conventionally built on compacted ballast and structural fill layers placed above the natural (subgrade) foundation. However, during train operations, track deteriorations occur progressively due to ballast degradation. The associated track deformation is usually accompanied by a reduction in both load bearing capacity and drainage, apart from imposing frequent track maintenance. Suitable ground improvement techniques involving plastic inclusions (e.g., geogrids) and energy absorbing materials (e.g., rubber products) to enhance the stability and longevity of tracks have become increasingly popular. This paper presents the outcomes from innovative research and development measures into the use of plastic and rubber elements in rail tracks undertaken at the University of Wollongong, Australia, over the past twenty years. The results obtained from laboratory tests, mathematical modelling and numerical modelling reveal that track performance can be improved significantly by using geogrid and energy absorbing rubber products (e.g., rubber crumbs, waste tire-cell and rubber mats). Test results show that the addition of rubber materials can efficiently improve the energy absorption of the structural layer and also reduce ballast breakage. Furthermore, by incorporating the work input parameters, the energy absorbing property of the newly developed synthetic capping layer is captured by correct modelling of dilatancy. In addition, the laboratory behavior of tire cells and geogrids has been validated by numerical modelling (i.e., Finite Element Modelling-FEM, Discrete Element—DEM), and a coupled DEM-FEM modelling approach is also introduced to simulate ballast deformation. Full article

(This article belongs to the Special Issue Advances in Computational Geomechanics)

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