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  • 67 Reads
Lockdown in Mars

In this work, we present a series of educational activities that rely on geological tools to dive in the science core standards for middle and high school. In this sense, Geology is not the subject to be studied, but the educational resource: we learn with Geology, rather than about Geology. Water is the common element to all activities, and the exploration of Mars (its geology, atmosphere, life conditions, …) becomes the engaging background. The primarly objective of these activities consistis on promoting the basis of scientific reasoning in students. Hence, we tested them with pre-service teachers, in order to have their opinions and comments about the strenghts and weaknesses of our proposal regarding critical reasoning.

Since the activities are so easy to carry out and future explorers of Mars will live in lockdown conditions, we also propose the adaptation of the original project to online learning, this is pandemic lockdown vs martian lockdown.

  • Open access
  • 84 Reads
Natural fracture systems in CBM reservoirs of the Lorraine-Saar coal Basin from stand-point of X-ray computer tomography

The Lorraine-Saar Basin is one of the largest geologically and commercially important Palaeozoic coal-bearing basins in Central Europe, which has considerable coal reserves in numerous coal beds. Geologically, the Lorraine Basin stands out by its up to 5 km sedimentary column and its inversion resulting in Paleozoic low-amplitude erosion in the range of 750 m (French part of the basin) and pre-Mesozoic (Permian) erosion between 1800 and 3000 m (the Saar coalfield or German part of the basin). Thermal maturation of wide spectra of organic-rich-matter ranging from dispersed organic matter in sedimentary clastic rocks to concentrated organic matter in coal seams has led to the formation of enormous coalbed methane (CBM) resource in many domains throughout the Carboniferous Westphalian and Stephanian sequences. Coal mines here are no longer operated to produce coal; however, gas generated in "dry gas window" compartments at a depth exceeding 3.5 km have escaped here via several major faults and fracture corridors forming "sweet spots gas" sites. Faults, a dense network of tectonic fractures together with post-mining subsidence effects also increased the permeability of a coal-bearing massive and provided pathways for the breathing of environmentally hazardous mine gases. Nearly all CBM plays can be classified as naturally fractured reservoirs. The Lorraine-Saar Basin is not exclusion indeed because of the long-term experience of industrial geological surveys during underground coal-mining in the past. The knowledge of geometrical features of fracture and cleat patterns is a crucial parameter for determining the absolute permeability of a resource play, its kinematics environment, and further reservoir simulation. The main focus of this contribution is to get an insight into the style and structural trends of natural fracture and cleat patterns in the basin based on the results of X-ray computer tomography (CT) to ensure proper technical decisions for efficient exploration and exploitation of coalbed methane reservoirs. To explore the architecture of solid coal samples we used X-ray computed tomography of coal specimen collected from the Westphalian D coal seam 10 of exploratory well Tritteling 1. The studied coal specimen (principle sample) and its 2 local subvolumes were inspected in 3 series of experiments (with resolutions of 30, 10, and 2 µm). At different levels of X-ray CT, we identified two quasi-orthogonal cleat systems including a smooth-sided face cleat of tensile origin and a curvilinear shearing butt cleat. The inferred tectonic zones, discrete fractures, and tectonically induced cleat patterns clearly possess features of self-similarity and usually align with directional stresses. Results of the treatment of obtained cleat patterns in terms of their connectivity relationship allowed distinguishing the presence within studied samples interconnected cleat arrays potentially facilitating success in CBM extraction projects.

  • Open access
  • 79 Reads
Mineralogical Composition and Physical – Mechanical Properties of Dasht - E - Taatrang Zar Sand Deposits (Afghanistan)
Published: 02 December 2020 by MDPI in The 3rd International Electronic Conference on Geosciences session Others

Sand is a common construction material used for various purposes; e.g. concrete, mortar, render, screed, and asphalt. The usage is depending on its fineness, and its fineness depends on mineralogical composition and physical – mechanical properties. This research aims to determine the chemical, mineralogical composition, and the physical – mechanical properties of the Dasht – e – Taatrang Zar sand deposits within the Qarabagh and Bagram districts of Kabul and Parwan provinces in Afghanistan. To achieve the objectives of research, library method for reviewing the literature, extensive field works for macroscopic studies and samples collection, and laboratory method for testament of collected samples were carried out. Totally 23 samples during the two phases of field works were collected and subjected to lab works for XRF, Schlich, and XRD analysis to determine the chemical and mineralogic composition, also sieve and Atterberg analysis, specific gravity, soundness, and alkali-silica reaction tests were performed for characterization of physical – mechanical properties. The results of tests show that Taatrang Zar sand deposits are considered as a suitable construction material and due its simple accessibility, the deposits can be a high potential of construction material supplier for the Kabul new city project (Dehsabz) in Kabul and adjacent Parwan and Kapisa provinces.

  • Open access
  • 109 Reads
Improving management of spatial data through spatial database

Entering the European Union Republic of Croatia took over INSPIRE directive called National spatial data infrastructure. Large amount of spatial data can be found through National spatial data infrastructure Geoportal. Data is available for view or download via different services, such as web mapping service or web feature service. Although different spatial data is available, it is hard to access useful information through Geoportal. Aim of this paper is to prepare spatial database which will gather different spatial data related to environmental engineering and present different queries and visualisation of the results. Main data used is related to protected areas in Republic of Croatia, register of environmental pollutants, air quality, exploitation and research fields of mineral resources, waste management, water management etc. Alongside National spatial data, Copernicus Land monitoring service EU-DEM, digital elevation model, is used. Classification of Sentinel-2 MSI data is used to provide land cover. Remotely sensed data are used in queries where aspect, slope and land cover affect the results. Two predefined SQL queries are discussed. First query is discussing danger of landslides and second query is discussing threats from illegal landfills and affect it has on environment. Predefined SQL queries enables users to quickly access needed data, even when original data is updated. All data, database, visualization and results are presented in open access software.

  • Open access
  • 87 Reads
Modeling Population Distribution in the Flood-Prone Area
Published: 07 December 2020 by MDPI in The 3rd International Electronic Conference on Geosciences session Poster Session

Population density is one of the key parameters for assessing the magnitude of population exposed to flood risk, and the better quality data we have, the better the assessment of risk. The aim of this study is to elaborate a high resolution spatially distributed population density grid, which estimates population at the commune scale with a reliability of over 90%. The novelty of the approach is population density estimation in a regular European grid, based on buildings vector data collected in the national topographic database. Using abductive reasoning in combination with statistics and spatial analysis, the authors extract approximate information about a population from the large scale topographic data. Moreover, linking the obtained population data with the cadastral data - by unique building identifier - allows for regular, quick and census survey independent updates of the population surface. A shortcoming of the approach is the issue of the possible existence of two houses per family, which leads to an overestimation of population. However, in the study area it affected only two of the total fourteen communes by 7-9%.

  • Open access
  • 72 Reads
Wildland fire suppression measures with water resources from nature applied for a region in Bulgaria
Published: 07 December 2020 by MDPI in The 3rd International Electronic Conference on Geosciences session Others

Wildland fires occur and spread more often in hard-to-reach areas, quickly covering big territories due to the presence of combustible materials in the understory along with favorable meteorological conditions. The occurrence of fires is mainly due to two factors - human activities and natural phenomena. The subject of the current research paper does not focus on these factors but on the idea of using the natural resources on fire-affected terrain. Fire suppression measures are primarily done with water and in sporadic cases with chemicals. In these cases, the provision of sufficient sources of water in the vicinity of the burning terrain is crucial, and this is the scope of the present work. That is why an analysis of the terrain with its hydrological characteristics - the flow in time, especially in the driest months of the year, is required. This assumption is used as a base and is illustrated with a specific example of a geographically defined area. This is done as proof of the idea proposed.

  • Open access
  • 86 Reads
Geochemical risks of diamond mining in Siberia

Geochemical risk is caused by the release of hazardous chemicals to the earth surface. Primary diamond deposits are located in difficult mining and geological conditions and represent natural geochemical anomalies associated with the mineral composition of rocks and groundwater, which contain a number of impurity elements with high toxic properties (Tl, Di, As, Cd, Hg), increased concentrations of heavy metals (Cu, Zn, Pb, Ti, V and others). The paper presents the physical-geographical and mining-geological conditions of the Sredne-Markhinsky diamondiferous region, where three large mining and processing divisions operate: Udachninsky, Aikhalsky and Nyurbinsky. In samples of soils, sediments, surface waters, drainage brines and vegetation were determined pH, organic matter (humus), total nitrogen, physical clay using potentiometric, photoelectric colorimetric, spectrophotometric methods and pipette method for particle size analysis. Gross and mobile forms of trace elements were determined by atomic absorption and atomic emission spectrometry. An assessment of the ecological and geochemical state of the study areas was carried out according to the indicator of total pollution (Zc), which is the sum of the excess of the concentration coefficients of chemical elements accumulating in anomalies. The zones of pollution and the greatest risk are localized. The groups of elements were identified that determined the natural and man-made anomalies.

  • Open access
  • 132 Reads
Building Extraction from Very High Resolution Stereo Satellite Images using OBIA and Topographic Information

The availability of very high resolution (VHR) satellite imagery (<1m) has opened new vistas in large scale mapping and information management in urban environments. Buildings are the most essential dynamic incremental factor in urban environment and hence their extraction is the most challenging activity. Extracting the urban features particularly buildings using traditional pixel based classification approaches as a function of spectral tonal value produces relatively less accurate results for these VHR Imageries. The present study demonstrates the building extraction using Pleiades panchromatic (PAN) and multispectral stereo satellite datasets of highly planned and dense urban areas in parts of Chandigarh, India. The stereo datasets were processed in photogrammetric environment to obtain the Digital elevation Model (DEM) and corresponding orthoimages. DEM’s were generated at 0.5 m and 2.0 m from stereo PAN and multispectral datasets, respectively. The orthoimages thus generated were segmented using Object Based Image Analysis (OBIA) tools. The object primitives such as scale parameter, shape, textural parameters, DEM derivatives were used for segmentation and indices were used to determine threshold values for building fuzzy rules for building extraction and classification. The rule based classification was carried out with defined decision rules based on object primitives and fuzzy rules. Two different methods were utilized for performance evaluation of the proposed automatic building approach. Overall accuracy, correctness and completeness were evaluated for extracted buildings. It was observed that overall accuracy was higher (> 93%) in areas having larger buildings and sparse built-up as compared to areas having smaller buildings and dense built-up.

  • Open access
  • 113 Reads
Identification of urban canyons in the City of São Paulo from Landsat 8 images

Cities in the last century have been suffering from the disorderly and unplanned growth of urban centers. Consequently, innumerable environmental problems started to plague these regions, one of them is the alteration of the surface temperature through the generation of heat islands and the urban canyons caused by the alterations in the natural landscape. Based on OLI and TIRS images from the Landsat 8 satellite, a soil cover map was generated, an image of Surface Temperature (ST) and the NDBI index, which highlight built-up areas, verifying and identifying urban canyon regions of São Paulo. From the results of the correlation of low, medium and high waterproofing areas generated by the soil cover map with the soil temperature images and the NDBI index, areas of medium waterproofing that had a (ST) similar to the areas of low waterproofing (28 ° C to 31 ° C). In this case, the areas of medium waterproofing should resemble the regions of high waterproofing (34 ° C to 37 ° C). Such regions have as main characteristic a low index of trees and a greater number of constructions, which causes an increase in temperature (heat islands). In this case, it is observed that the regions of medium waterproofing are influenced by the height and spacing of the buildings, which generate wind corridors and shading of the surface, decreasing the temperature of the region and generating urban canyons. Thus, it is concluded that it is possible to identify regions of urban canyons through multispectral and thermal images. The methodology used allows a diagnosis of the islands of heat islands and urban canyons and to evaluate actions taken in these areas in order to mitigate the problems that such phenomena can cause, mainly related to the population's climate and health.

  • Open access
  • 82 Reads
Coleoptera from the late Pleistocene forest refugium of the West Siberian Plain

Open unforested landscapes were predominated in the late Pleistocene (MIS 3 and MIS 2) of West Siberian Plain. This is shown in particular by the entomological data. Insect late Pleistocene assemblages from the north (70-60° N) were considered as the arctic type, and from the south (57-51° N) were assigned as non-analogous periglacial type or so called “Otiorhynchus-type fauna” (Legalov et al., 2016; Gurina et al., 2019). Forests are not typical for this time, and insects associated with arboreal vegetation were found in the late Pleistocene deposits sporadically.

One of the sites where Quaternary deposit insect assemblages include forest insects are Suzun-1 (53°43'54'' N, 82°10'54'' E) and Suzun-2 (53°44'00'' N, 82°11'01'' E). Both are located in the Suzun River valley, right tributary of upper Ob River (Novosibirskaya Oblast, Russia). Obtained radiocarbon dates are as follows. 24893–25966 cal yr BP for Suzun-1 correspond to the end of MIS 3, and 20379–20699 cal yr BP for Suzun-2 correspond to the beginning of MIS 2.

Insect assemblages Suzun-1 and Suzun-2 represented mostly by Coleoptera are very similar to each other. They include a lot steppe species (Harpalus salinus, H. amputatus, Porcinolus murinus, Otiorhynchus cf. ursus, O. subocularis) and several tundra species (Diacheila polita, Curtonotus cf. alpinus, Pterostichus (Cryobius) spp.) that is typically for the periglacial assemblages. However, in contrast to other known late Pleistocene entomocomplexes of the West Siberian Plain, some forest species (Phloetribus spinulosus, Carabus henningi, C. regalis, Pterostichus cf. altainus, Pterostichus cf. maurusiacus) were found in the Suzun-1 and Suzun-2 sites.

The presence of bark beetle Phloetribus spinulosus associated with Picea allows reconstructing fir forest at river valleys. However the proportion of steppe and forest species of Coleoptera in the Suzun assemblages shows the forests probably occupied restricted area only, and opened steppe landscapes predominated in the region. The high similarity of Suzun-1 and Suzun-2 insect assemblages confirms a gradual MIS3 – MIS2 transition in the region, and indicates the forest refugium existed here quite long time, at least a few thousand years.

The study was partially supported by the Russian Foundation for Basic Research (project no.19-04-00963‐a) and the Federal Fundamental Scientific Research Program for 2013–2020 (project no. AAAA‐A16‐116121410121‐7).

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