Geological Phenomena Research Articles

GEOLOGICAL AND GEOPHYSICAL CONSIDERATIONS REGARDING THE MINERAL AND GEOTHERMAL WATERS FROM THE RAMNICU VALCEA - GOVORA AREA

For understanding of complex geological and geophysical phenomena, regarding the mineral and geothermal waters, we must base on the whole of knowledge and available data for the study area. The input data include: digital terrain models, geological and geophysical maps, sections, drill-holes and geological interpretation, for assemble together into the same space data from various sources, in order to ensure geometrical coherence. Also, the database includes measurements of deuterium (δD (‰)) and overall salt content (∆d (mg/l)) expressed as the difference in density between a distilled water taken as a standard and water sample. Are important to take into account the geology 'boundary' data (geology contacts, interfaces and limits), the deep geology and processing/filtering of geophysical data with properly algorithms. The type of filtering of gravimetric and magnetic data must be chosen based on the depth of the model we want to get. This is necessary because the values of the geophysical parameters recorded at the surface of the terrain contain weighted average information from both the surface and from different depths, even to the base of the Lithosphere. In this paper we made some geological and geophysical considerations regarding the mineral and geothermal waters from the Ramnicu Valcea - Govora area. The types of water sources targeted are mineral springs, boreholes and surface water in the area

Activated Bledug Kuwu’s Clay as Adsorbent Potential for Synthetic Dye Adsorption: Kinetic and Thermodynamic Studies

Bledug Kuwu is one of the geological phenomena as a mud volcano that occurs in Kuwu, Purwodadi, Grobogan, Central Java, Indonesia. The evaluation of Bledug Kuwu’s clay as one of the adsorbents for synthetic dyes has been carried out. The preparation of the adsorbent started with washing the clay with distilled water, followed by activation with a solution of hydrochloric acid (1 M) under mechanistic stirring for overnight. The C−H and O−H groups found on the clay adsorbent could attract methylene blue by dispersion forces and hydrogen bonding. Hydrocloric acid activation process for clay can increase surface area from 49 to 70 m2.g−1, meanwhile, reducing the average crystal size from 48.3 to 43.4 nm. The dye removal capacity increased from 34 to 40 mg.g−1 in corresponding to the increase of the temperature from 30 to 50 °C. The results showed that the equilibrium adsorption capacity of activated Bledug Kuwu’s clay reached 99% in an adsorption time of 20 min. The kinetic models of methylene blue adsorption onto BKC and ABKC adsorbents follow the pseudo-second order and the adsorption process is spontaneous with free energy (ΔG) as −23.519 kJ.mol−1. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

VETIVER ROOT PLANTING FOR PREVENTION AND MITIGATION OF LANDSLIDES IN DISASTER-PRONE AREAS, NGANJUK, EAST JAVA

Landslide is the transfer of slope-forming material in the form of rocks, debris, soil moving down or out of the slope. Geolologically, landslides are a geological phenomenon with a movement of land such as falling rocks or large lumps of land (Nandi, 2007). The majority of Nganjuk Regency, East Java, is at high risk of landslides. Reporting from Tirto.id news on February 19, 2021, there was a landslide in Ngetos Subdistrict, Nganjuk which claimed many victims. Nineteen people died, 20 were injured and 10 houses were severely damaged. Ngetos village is the largest village with the most populous population in Nganjuk. Unit of Natural Disease Support from Faculty of Medicine, Community Service Team of the Department of Anesthesiology and Reanimation Faculty of Medicine Universitas Airlangga in collaboration with the Center of Environmental Health Engineering and Disease Control (BBTKLPP) Surabaya in efforts to overcome landslide disasters that occurred in Nganjuk. Assistance provided includes medical assistance and environmental development as one of the disaster mitigation efforts. One of the mitigation measures carried out through this activity is reforestation by planting vetiver roots. Vetiver Roots are known as landslide prevention plants because their roots can reach depths soil of down to 5 meters. One of the causes of landslides is the lack of vegetation on the ground so it is prone to movement, especially if it rains heavily because there is no anchoring. Therefore, this activity is considered important to prevent repeated landslides.

Fine Geological Modeling of Complex Fault Block Reservoir Based on Deep Learning

Nowadays, people’s demand for underground mineral resources is increasing, and geological disasters have occurred frequently in recent years. Geological disasters refer to geological effects or geological phenomena that are formed under the action of natural or man-made factors, causing loss of human life and property, and damage to the environment; such as landslides, collapses, mudslides, and ground subsidence. Under such a background, people must accelerate the exploration of complex geological structures. This paper is aimed at using the methods and concepts of deep reinforcement learning. Deep learning is to learn the inherent laws and representation levels of sample data. The information obtained during these learning processes is of great help to the interpretation of data such as text and images. In this way, the fine geology of complex fault-block reservoirs is modeled and studied. Geological structures and phenomena are discussed through convolutional neural network models and computer techniques. At the same time, the multitask bird recognition network is used to extract and classify geological images, so as to construct geological model maps with different spatial structures. Finally, the quality of the fault reconstruction model, the calculation of reservoir geological simulation reserves, and the evaluation of the water injection development effect of complex fault blocks are analyzed. In the evaluation of the development effect of water injection in complex fault blocks, comparing the relationship curve between the actual comprehensive water content and the oil recovery factor with the standard curve, the comprehensive water content of the initial block increased rapidly. Through timely and dynamic water allocation and comprehensive management, the water cut rising speed is controlled. The current comprehensive water cut of the reservoir is between 60% and 80%, the actual curve is between 25% and 35%, and the estimated waterflooding recovery is about 30%.

Giant sheath-folded nappe stack demonstrates extreme subhorizontal shear strain in an Archean orogen

Abstract Giant sheath-folded nappes are associated with suture zones and emplacement of far-traveled allochthons in Phanerozoic orogens, demonstrating a rare but significant geologic phenomenon indicative of modern-style plate tectonics. We document the world's oldest-known subhorizontal mega-scale sheath fold from Archean Alpine-style nappes of the Central orogenic belt, North China craton. The Zanhuang nappes are recumbent Alpine-style forearc-affinity metabasaltic and metasedimentary nappes emplaced over a passive continental margin in the Archean, marking an ancient suture zone. Field evidence shows multiscale sheath folds from decimeters to tens of meters in size, and our three-dimensional fence profile, fold hinges, kinematic lineations, and lithological traces define an ~1-km-long (parallel to the x-axis) sheath fold in the core of the nappe stack. Structural analysis statistically demonstrates the macro-scale recumbent sheath-folded nappe preserves a complete 180° hinge-line curvature. The giant sheath fold plunges northwest, reflecting its formation during non-coaxial, top-to-the-southeast shearing with extremely high shear strain (γ ≥10), equated to >10 km of ductile slip on the bounding surfaces. Slip vectors derived from S-C fabrics on overturned limbs are consistent with rotation into the southeast-directed transport direction, parallel to the similarly rotated fold hinges. Comparison of the giant sheath-folded nappes from the Archean Zanhuang example with mega-scale sheath folds in Phanerozoic and Proterozoic orogens shows that Neoarchean lithosphere was stiff enough to allow tectonics to operate in a manner analogous to modern-style plate tectonics.

Color Balance Method of Dense Point Cloud in Landslides Area Based on UAV Images

Landslides are a natural geological phenomenon and often cause economic losses, property damage, and loss of lives. The detection and recognition based on the dense point cloud derived from Unmanned Aerial Vehicle (UAVs) images play an important role in understanding the mechanism of landslides. However, the brightness difference of UAV images with large altitude differences usually makes the dense point cloud within a landslide area show color stratification, and the processing results of popular commercial and open-source software are not ideal. In this study, a multi-view UAV image brightness compensation method based on regular 3D points is proposed, and is combined with the open-source software OpenMVG and OpenMVS to obtain a dense point cloud with balanced color on the landslide’s surface. The selected study area is located in the active landslide region caused by the Tengqing coal mining area in Guizhou Province, China. The terrain following flight method was used to acquire complete high resolution UAV images of the study area. Experimental results show that the global gain and offset compensation methods proposed in this study can effectively reduce the 22.3% brightness difference in the overlapping area of the adjacent images. The comparison results and the processing results of other commercial software show that the method can be applied to the color balance of the dense point cloud for UAV images with large-altitude differences.

Evaluation of the depth of seasonal defrosting at change of thermal physical characteristics of bulk soils

Western Siberia is an important base for oil and gas production. The main number of deposits are arranged on bulk soils that violate the thermal regime of rocks and cause the development of a variety of engineering and geological processes and phenomena. The paper presents the results of determining the thermophysical characteristics of bulk soils selected at four fields in Western Siberia. Thermotechnical calculations were carried out to determine the depth of seasonal thawing and an assessment was made of the influence of the thermophysical properties of bulk soils on the change in thickness of the seasonally thawed layer.

Scenario Expression Method for Regional Geological Structures

Knowing the GIS expression of geological phenomena is an important basis for the combination of geology and GIS. Regional geological structures include folds, faults, strata, rocks, and other typical geological phenomena and are the focus of geological GIS research. However, existing research on the GIS expression of regional geological structure focuses on the expression of the spatial and attribute characteristics of geological structures, and our knowledge of the expression of the semantic, relationship, and evolution processes of geological structures is not comprehensive. In this paper, a regional geological structure scene expression model with the semantic terms positional accuracy, geometric shape, relationship type, attribute type, and time-type attributes and operations is proposed. A regional geological structure scenario markup language (RGSSML) and a method for mapping it with graphics are designed to store and graphically express regional geological structure information. According to the geological time scale, a temporal reference coordinate system is defined to dynamically express the evolution of regional geological structures. Based on the dynamic division of the time dimension of regional geological structures, the expression method of “time dimension + space structure” for the regional geological structure evolution process is designed based on the temporal model. Finally, the feasibility and effectiveness of the regional geological structure scene expression method proposed in this paper is verified using the Ningzhen Mountain (Nanjing section) as an example. The research results show that the regional geological structure scene expression method designed in this paper has the following characteristics: (1) It can comprehensively express the spatial characteristics, attribute characteristics, semantics, relationships, and evolution processes of regional geological structures; (2) it can be used to realize formalized expression and unified storage of regional geological information; and (3) it can be used to realize dynamic expression of the regional geological structure evolution process. Moreover, it has significant advantages for the expression of regional geological structure semantics, relationships, and evolution processes. This study improves our knowledge of the GIS expression of regional geological structures and is expected to further promote the combination and development of geology and GIS.

Evolution Assessment of Mining Subsidence Characteristics Using SBAS and PS Interferometry in Sanshandao Gold Mine, China

Ground subsidence is a common geological phenomenon occurring in mining areas. As an important Chinese gold mine, Sanshandao Gold Mine has a mining history of 25 years, with remarkable ground subsidence deformation. Mining development, life security, property security and ecological protection all require comprehension of the ground subsidence characteristics and evolution in the mining area. In this study, the mining subsidence phenomenon of the Sanshandao Gold Mine was investigated and analyzed based on Persistent Scatterer Interferometry (PSI) and small baseline subset (SBAS). The SAR (synthetic aperture radar) images covering the study area were acquired by the Sentinel-1A satellite between 2018 and 2021; 54 images (between 22 February 2018 and 25 May 2021) were processed using the PSI technique and 24 images (between 11 April 2018 and 12 July 2021) were processed using the SBAS technique. In addition, GACOS (generic atmospheric correction online service) data were adopted to eliminate the atmospheric error in both kinds of data processing. The interferometric synthetic aperture radar (InSAR) results showed a basically consistent subsidence area and a similar subsidence pattern. Both InSAR results indicated that the maximum LOS (line of sight) subsidence velocity is about 49 mm/year. The main subsidence zone is situated in the main mining area, extending in the northwest and southeast directions. According to the subsidence displacement of several representative sites in the mining area, we found that the PSI result has a higher subsidence displacement value compared to the SBAS result. Mining activities were accompanied by ground subsidence in the mining area: the ground subsidence phenomenon is exacerbated by the increasing mining quantity. Temporally, the mining subsidence lags behind the increase in mining quantity by about three months. In summary, the mining area has varying degrees of ground subsidence, monitored by two reliable time-series InSAR techniques. Further study of the subsidence mechanism is necessary to forecast ground subsidence and instruct mining activities.

Geoinspired syntheses of materials and nanomaterials

The search for new materials is intimately linked to the development of synthesis methods. In the current urge for the sustainable synthesis of materials, taking inspiration from Nature's ways to process matter appears as a virtuous approach. In this review, we address the concept of geoinspiration for the design of new materials and the exploration of new synthesis pathways. In geoinspiration, materials scientists take inspiration from the key features of various geological systems and processes occurring in nature, to trigger the formation of artificial materials and nanomaterials. We discuss several case studies of materials and nanomaterials to highlight the basic geoinspiration concepts underlying some synthesis methods: syntheses in water and supercritical water, thermal shock syntheses, molten salt synthesis and high pressure synthesis. We show that the materials emerging from geoinspiration exhibit properties differing from materials obtained by other pathways, thus demonstrating that the field opens up avenues to new families of materials and nanomaterials. This review focuses on synthesis methodologies, by drawing connections between geosciences and materials chemistry, nanosciences, green chemistry, and environmental sciences.

ЭМИССИЯ ПАРНИКОВЫХ ГАЗОВ, ГЛОБАЛЬНОЕ ПОТЕПЛЕНИЕ И НЕФТЕГАЗОВАЯ ОТРАСЛЬ РОССИИ

Due to global climate change, the degradation of permafrost rocks has intensified, threats of large-scale damage and destruction of various objects in cities and towns, as well as the infrastructure of oil and gas fields, have arisen and are expanding in the territorial plan. The necessity of expanding the study, forecasting and reducing the threats of exogenous and dangerous endogenous geological processes and phenomenon, among which powerful blowouts, self-ignition and explosions of gas with the formation of giant craters, stand out is substantiated. The importance of developing domestic technical means and technologies for complex monitoring of dangerous phenomenon was noted. It is shown that despite the adopted legislative acts, the share of associated petroleum gas utilization is decreasing. New threats to the national security of the country are analyzed.

Revisiting the deep-sea Atlantic gastropod species Scaphander gracilis Watson, 1883 (Gastropoda: Cephalaspidea: Scaphandridae): first data on its anatomy, systematics, and ecology

ABSTRACT Scaphander gracilis Watson, 1883 is a deep-sea Cephalaspidea gastropod species endemic to the Azores in the mid-North Atlantic, and which was up to now only known from empty shells with a unique thick callus. Here, we describe for the first time the morphology of this snail species from anatomical dissections and provide a DNA barcode. A phylogeny based on the gene marker cytochrome c oxidase subunit I was inferred to test the position of S. gracilis among the genus Scaphander. In addition, the ABGD species delimitation method was employed and uncorrected p-distances were estimated. The sister relationship of S. gracilis was not resolved, but it clustered with the Atlantic species S. meridionalis and S. nobilis and the Pacific species S. grandis, S. mundus, and S. subglobosus. The smallest genetic distance was to the NE Pacific species S. grandis (4.29% in COI). Foraminifera were found in the digestive tract and the species is confirmed alive at depths between 2065−2066 m. The fact that S. gracilis was found on both sides of the Mid-Atlantic Ridge suggests that this significant geological phenomenon is not an insurmountable barrier for dispersal in this species.

Landslides vs Archaeology

Landslides are one of the few types of natural hazards that have affected Sweden regularly in the recent past. We can expect that this geological phenomenon will only increase in frequency in the near future given the ongoing processes of anthropogenic climate change, and this likelihood motivates some historical retrospection. This paper explores how landslides have impacted archaeological sites in Västra Götaland, the country’s most landslide-prone region, from the mid-twentieth century onwards, and how, in turn, archaeologists have had to respond to these disasters. The 1957 Göta, 1973 Fröland, 1977 Tuve and 2006 Småröd landslides are highlighted in particular, as is the landslide-impacted site Hjälpesten. Connections are made to other different but related archaeologies of hazard and disaster, providing insights into the impact that climate change has had and will have on the discipline. While the paper showcases a set of local case studies, it is further argued that its findings have relevance for other areas as well, calling for the attention of the cultural heritage sector.

Application of InSAR satellite method for mapping of active landslides in Bulgaria – opportunities and perspectives

Abstract. Landslides are geological phenomena that are spread on Bulgarian territory mainly along the northern Black Sea coast and on the right banks of the Danube in the western part of the country. Mitigation of the negative effects of these destructive geological phenomena is the compilation of inventory maps of their distribution and registers with the main characteristics of the individual landslides. Conventional methods for making such maps are time-consuming and resource-intensive. Modern satellite, air and ground-based remote sensing technologies facilitate the production of landslide maps, reducing the time and resources required to compile and systematically update them. In this paper, we demonstrate the applicability of Differential Sentinel-1A satellite SAR interferometry (DInSAR) to assess the movement activity and use the information for further updating the national landslide inventories in Bulgaria. We perform several analyses based on multi-temporal InSAR techniques of Sentinel-1A data over selected areas prone to landslides. The use of new opportunities for free access to satellite images, which can be applied in conjunction with other methods, greatly facilitates the processes of inventory, mapping and study of landslides.

Peculiarities of selecting woody plants for anatomy analysis in various environments

Methods for studying woody plants anatomy are now very diverse. We modified the guidelines for bark studies developed for wood analysis at all stages of preparing the woody plant samples for microscope study. For the first time, we used separation to separate hard and soft fractions of the bark tissue. Correct approach to selection of plant samples and further laboratory manipulations ensures validity of the results of our study. We select the size of the sampling area depending on the type of vegetation. In every habitat, we also include transects along the gradient of height above sea level or the impact from the source of natural stress. The results of our research will help study landscape changes during exogenous geological processes and phenomena using biological indication of geosystems.

Students’ Reactions to Virtual Geological Field Trip to Baengnyeong Island, South Korea

In this study, we evaluated affective components of the learning processes of students after being exposed to a virtual geology field trip of the Baengnyeong Island, South Korea. Changes in students’ cognition of and interest in science and scientific attitude were measured before and after exposure to the virtual field trip. We exposed 106 middle school students to the program and our results revealed that this program had a positive impact on their scientific attitude (p value = 0.014) but no significant changes were observed in the students’ cognition of and interest in science (p value = 0.166). The significant finding from this study was that the VFT program can bring positive scientific attitude as a component of affective learning process. The affective learning process influences the cognitive learning processes and eventually the academic achievement of the students can be improved. In the students’ satisfaction survey, the highest satisfaction level was in the convenience of the program. As access to Baengnyeong Island is limited, though the island is an ideal location for studying geological phenomena, the VFT can be a useful tool for instilling a positive scientific attitude in students via indirect field experience. It can be a good alternative to bridge the education gap between students with special needs who are less mobile and other students.

Investigation of residual strain in quartzite using neutron diffraction: Interpretation and self‐consistent modelling

The residual strain determination by neutron diffraction has been performed on a set of five natural quartzite samples collected from Betic Cordilleras (Spain) and Sivas Basin (Turkey). The starting idea was to document an earlier conclusion about the texture components related either to deformation or recrystallization phenomena. Thereafter, as a consequence of the rock inhomogeneity, the complete strain tensor has been determined for each sample and discussed by taking into consideration the present‐day knowledge in material sciences. The imposed macroscopic deformation observed at the sample locality led us to consider the form of the residual strain tensor as possibly representative of the natural finite plastic deformation suffered at the sample scale. Based on this, those tensors have been fitted to plastic tensors and introduced in texture simulations using a visco‐plastic self‐consistent (VPSC) model. The results demonstrate that the complete and meaningful strain tensor determination in rocks could be used as an experimental input in numerical modelling. This new combination of experimental and numerical approaches was validated and could help to better understand some geological phenomena.

Compound jetting from bubble bursting at an air-oil-water interface

Bursting of bubbles at a liquid surface is ubiquitous in a wide range of physical, biological, and geological phenomena, as a key source of aerosol droplets for mass transport across the interface. However, how a structurally complex interface, widely present in nature, mediates the bursting process remains largely unknown. Here, we document the bubble-bursting jet dynamics at an oil-covered aqueous surface, which typifies the sea surface microlayer as well as an oil spill on the ocean. The jet tip radius and velocity are altered with even a thin oil layer, and oily aerosol droplets are produced. We provide evidence that the coupling of oil spreading and cavity collapse dynamics results in a multi-phase jet and the follow-up droplet size change. The oil spreading influences the effective viscous damping, and scaling laws are proposed to quantify the jetting dynamics. Our study not only advances the fundamental understanding of bubble bursting dynamics, but also may shed light on the airborne transmission of organic matters in nature related to aerosol production.

Deep/Transfer Learning with Feature Space Ensemble Networks (FeatSpaceEnsNets) and Average Ensemble Networks (AvgEnsNets) for Change Detection Using DInSAR Sentinel-1 and Optical Sentinel-2 Satellite Data Fusion

Differential interferometric synthetic aperture radar (DInSAR), coherence, phase, and displacement are derived from processing SAR images to monitor geological phenomena and urban change. Previously, Sentinel-1 SAR data combined with Sentinel-2 optical imagery has improved classification accuracy in various domains. However, the fusing of Sentinel-1 DInSAR processed imagery with Sentinel-2 optical imagery has not been thoroughly investigated. Thus, we explored this fusion in urban change detection by creating a verified balanced binary classification dataset comprising 1440 blobs. Machine learning models using feature descriptors and non-deep learning classifiers, including a two-layer convolutional neural network (ConvNet2), were used as baselines. Transfer learning by feature extraction (TLFE) using various pre-trained models, deep learning from random initialization, and transfer learning by fine-tuning (TLFT) were all evaluated. We introduce a feature space ensemble family (FeatSpaceEnsNet), an average ensemble family (AvgEnsNet), and a hybrid ensemble family (HybridEnsNet) of TLFE neural networks. The FeatSpaceEnsNets combine TLFE features directly in the feature space using logistic regression. AvgEnsNets combine TLFEs at the decision level by aggregation. HybridEnsNets are a combination of FeatSpaceEnsNets and AvgEnsNets. Several FeatSpaceEnsNets, AvgEnsNets, and HybridEnsNets, comprising a heterogeneous mixture of different depth and architecture models, are defined and evaluated. We show that, in general, TLFE outperforms both TLFT and classic deep learning for the small dataset used and that larger ensembles of TLFE models do not always improve accuracy. The best performing ensemble is an AvgEnsNet (84.862%) comprised of a ResNet50, ResNeXt50, and EfficientNet B4. This was matched by a similarly composed FeatSpaceEnsNet with an F1 score of 0.001 and variance of 0.266 less. The best performing HybridEnsNet had an accuracy of 84.775%. All of the ensembles evaluated outperform the best performing single model, ResNet50 with TLFE (83.751%), except for AvgEnsNet 3, AvgEnsNet 6, and FeatSpaceEnsNet 5. Five of the seven similarly composed FeatSpaceEnsNets outperform the corresponding AvgEnsNet.

Landslide Susceptibility Assessment Using an AutoML Framework.

The risks associated with landslides are increasing the personal losses and material damages in more and more areas of the world. These natural disasters are related to geological and extreme meteorological phenomena (e.g., earthquakes, hurricanes) occurring in regions that have already suffered similar previous natural catastrophes. Therefore, to effectively mitigate the landslide risks, new methodologies must better identify and understand all these landslide hazards through proper management. Within these methodologies, those based on assessing the landslide susceptibility increase the predictability of the areas where one of these disasters is most likely to occur. In the last years, much research has used machine learning algorithms to assess susceptibility using different sources of information, such as remote sensing data, spatial databases, or geological catalogues. This study presents the first attempt to develop a methodology based on an automatic machine learning (AutoML) framework. These frameworks are intended to facilitate the development of machine learning models, with the aim to enable researchers focus on data analysis. The area to test/validate this study is the center and southern region of Guerrero (Mexico), where we compare the performance of 16 machine learning algorithms. The best result achieved is the extra trees with an area under the curve (AUC) of 0.983. This methodology yields better results than other similar methods because using an AutoML framework allows to focus on the treatment of the data, to better understand input variables and to acquire greater knowledge about the processes involved in the landslides.