Application Of Geophysical Methods Research Articles

Application of Geophysical Methods in the Identification of Mineralized Structures and Ranking of Areas for Drilling as Exemplified by Alto Guaporé Orogenic Gold Province

Mineral exploration works conducted in the Alto Guaporé Gold Province (AGGP), situated in the southwest region of the Amazon Craton in Brazil, faces the challenges of many gold provinces around the world, i.e., declines in the discoveries of new economic deposits and increases in exploration costs. Ground geophysical methods, combined with structural analyses and geological mapping, are valuable tools that have potential to improve accuracy in selecting exploration targets and in determining drilling locations. AGGP deposits are primarily associated with regional N20°–W50° inverse faulting and sheared geologic contacts between Meso-Neoproterozoic siliciclastic metasedimentary rocks and Mesoproterozoic basement (granite and volcano–sedimentary sequences). Mining currently occurring in the central portion of the province drives exploration works towards the many existing targets at the area. Among them, the ABP target is one of the most promising for being located few kilometers north of the Pau-a-Pique mine. At the ABP target, gold is associated with hydrothermal alteration located in the sheared contacts and in the hinge zone of folded metasedimentary sequence. Hydrothermal phases include Fe-oxides, sulfide (py), muscovite and quartz veins. In this study, we use magnetic and geoelectric (induced polarization) surveys coupled with structural and geological mapping to identify potential footprints within the ABP target. The results from induced polarization (IP) profiles successfully mapped the shape and orientation of the main structures down to approximately 350 m at the ABP target, indicating potential locations for hydrothermal alteration hosting gold. Additionally, 3D magnetic data inversions illustrated the distribution of magnetic susceptibilities and magnetization vectors associated with shear zone structures and isolated magnetic bodies. Magnetic data highlighted fault zones along the contacts between metamorphic rocks and granites, while IP data identified areas with high chargeability, correlating with sulfidation zones mineralized with gold. These findings suggest a metallogenic model where gold deposits are transported through deep structures connected to regional faults, implying significant tectonic and structural control over gold deposition. The results underscore the potential of multiparameter geophysics in identifying and characterizing deposits in both deep and strike, thereby advancing our understanding of mineral occurrences in the region and enhancing the search for new mineralized zones.

Applications of geophysical methods in agriculture and their potential in Vietnam

Geophysical methods are very popular in Vietnam and have been applied for several decades in deep-earth investigations such as geological mapping, mineral resource searching, and especially oil and gas exploration. In the world, they have proven to be great tools in agriculture as well for soil characterization and monitoring thanks to their notable advantages including rapid data acquisition, large data coverage, high data density, non-destructive and inexpensive survey implementation. However, in Vietnam, the applications of geophysical methods in agriculture have received little attention probably due to the lack of suitable equipment and data processing techniques. This article gives an overview of popular geophysical methods being applied in agriculture in several countries to characterize and monitor soil properties such as moisture, salinity, density, texture, structure, porosity, etc. The main uses of each method are summarized, and relevant publications are given for reading recommendations with the aim of suggesting similar applications in Vietnam. Accordingly, Ground Penetrating Radar (GPR) and Electromagnetic Induction (EMI) are the most versatile with minimum field crew for data acquisition. They should be prioritized to try in Vietnamese agriculture. Since EMI equipment is not currently available in Vietnam, only a GPR test survey was implemented in the Agricultural Academy experimental field by the authors of Hanoi University of Mining and Geology. The preliminary result shows that the biggest challenge is to find reliable techniques to accurately infer soil properties from measured geophysical parameters, which have no explicit relationship with soil properties. Noise suppression is another problem that needs to be addressed to ensure sufficient data quality.

A simple method for estimating the coarse lateral root biomass of shrubs using ground-penetrating radar: Validation by Caragana microphylla Lam. in Inner Mongolia

The potential increases in carbon stocks in arid regions due to recent shrub encroachment have attracted extensive interest among both ecologists and carbon policy analysts. Quantifying the shrub root biomass amount in these ecosystems is essential to understanding the ecological changes occurring. In this paper, we proposed a simple nondestructive method for estimating the coarse lateral root biomass of shrubs based on the root counts obtained from ground-penetrating radar (GPR) radargrams. Root data were gathered via field experiments using GPR with antenna center frequencies of 900 MHz and 400 MHz. Five Caragana microphylla Lam. shrubs of different sizes were selected for measuring objects, and a total of 40 GPR survey lines were established for GPR data acquisition. The soil profile wall excavation method was used to obtain the total root biomass from each radargram. A model for estimating the root biomass was built by establishing the relationship between the root biomass in each profile and the root counts interpreted from the radargrams. According to the mathematical relationship between the root diameter and root biomass, the proxy root radius was derived, which could explain the rationality of the proposed model from the biological mechanism. The established model provided high confidence in estimating the root dry biomass using the GPR data obtained at the two antenna frequencies (R2= 0.73 for 900 MHz and R2= 0.71 for 400 MHz). The leave-one-out cross-validation results showed that the model exhibits satisfactory performance. This study expands the application of geophysical methods in root research and offers a new simplified method for estimating the root biomass from GPR data under field conditions.

Integrated application of geophysical methods in Earth dam monitoring

Integrated application of geophysical methods in Earth dam monitoring

Application of Geophysical Methods for Investigation of Groundwater Potential in Layunrun Village, Ogun State, Southwestern Nigeria

An investigation of the groundwater potential of the area for tube well construction has been conducted in Layunrun village in a typical basement complex of Ogun State using electromagnetic and electrical resistivity techniques in geophysical exploration. Six (6) electromagnetic profiles were used, and twenty-eight (28) Vertical Electrical Soundings (VES) were performed along some of the profiles' potential regions. The typical partial curve matching utilized to create the VES curves was examined, and the results were used to create themed maps of the region. Within the study area, between four and six geoelectric layers were found. These layers are Topsoil, weathered layer (clay), weathered layer, fractured basement, and fresh basement. According to the findings, a bigger percentage of the land has an overburden thickness ranging from 9 to 17 m, with a maximum overburden of about 23 m. It also showed how well fractured the research area is, with thicknesses of the fractures varying from about 12 m to more than 30 m. The study area has a good chance of accumulating groundwater and, consequently, developing groundwater through digging boreholes. The outcomes also suggested that a community with similar geological settings may use the electromagnetic method in addition to the electrical resistivity method to identify places with high groundwater potentials.

Application of geophysical methods in fine detection of urban concealed karst: A case study of Wuhan City, China

Application of geophysical methods in fine detection of urban concealed karst: A case study of Wuhan City, China

Editorial: Evaluation, projection, and prevention of dynamic geological disasters: advances and applications of geophysical methods and numerical modeling

Editorial: Evaluation, projection, and prevention of dynamic geological disasters: advances and applications of geophysical methods and numerical modeling

Prospective methods for determining water losses from irrigation systems to ensure food and water security of Ukraine

Purpose. To develop a complex system for technical diagnostics of soil hydrotechnical structures of irrigation systems for operative identification of damaged sites, reduction of nonproduction water losses, and maintaining ecological and economic efficiency of the hydroeconomic national complex in the context of water and food security. Methodology. The result of the represented scientific study is reached by complex application of geophysical methods of the Earth’s natural pulse electromagnetic field (NPEMFE) and vertical electrical sounding (VES). That allows determining qualitative indices and parameters of the damaged sites of hydrotechnical structures and water filtration paths. Mathematical methods for determining quantitative parameters of filtration losses are applied. Analytical and technoeconomic comparison of some most widely used methods with the complex of techniques proposed in the study are performed. Findings. Field studies and analytical calculations helped determine that, depending on the design parameters of retention basins and modes of their operations, water losses are from 50 to 60 m3/month per 1 m of the structure length. In some cases total filtration losses per month can reach up to 100 m3 per 1 m of the length. As for the monetary equivalent, in terms of average water cost being 0.12 EUR/m3, water loss in one standard retention basin with the conventional dimensions of 100  100 m is EUR 2.5 thousand per month (EUR 12.5 thousand per season). Originality. The possibility of using a complex of geophysical methods for diagnosing technical conditions of soil dams of retention agricultural basins has been substantiated scientifically. The complex is of high informativity making it possible to determine rapidly the sites with increased filtration in the hydrotechnical objects. According to the comparison of the available models for evaluating possible filtration losses from the retention basins of irrigation systems, the parameters of estimate indicators, ensuring high reliability of the results, have been substantiated. Practical value. Point determination of the sites with filtration water losses makes it possible to focus the repair and renewal operations on the most damaged sites that reduce considerably the time and costs along with the increase in general efficiency of the irrigation system operation.

Опыт применения неинвазивных методов геофизики при решении задач археологии

На сегодняшний день в мировой практике применение неинвазивных геофизических методов при решении археологических задач является неотъемлемой частью работ на начальном этапе исследований. В статье рассматривается опыт применения малоглубинной геофизики на различных археологических объектах Наманганской, Джизакской и Сурхандарьинской областей Республики Узбекистан. Целью работ являлось изучение древних погребений курганного типа, выделение культурного слоя на местах стоянок древних людей, а также исследование построек и объектов жизнедеятельности городищ Кушанского периода территории Северной Бактрии. Исследования проводились лабораторией «Геофизики и наноминералогии» Центра передовых технологий комплексом геофизических методов, включающем в себя магниторазведку, георадиолокационную съемку и электротомографию (ЭТ). Магнитная съемка проводилась с помощью протонных магнитометров Geometrics 856АХ (США), при этом расстояние между датчиками составляло 50 см, таким образом шаг между точками измерений и профилями составлял 50 см. Георадарные измерения выполнялись георадаром PulseEKKO PRO компании Sensors & Software (Канада) по системе сеточных профилей с шагом между профилями 1 м и антенной с центральной частотой 100 МГц. При электроразведочных измерениях методом ЭТ использовался 72 электродный георезистивиметр M.A.E. X-612EM (Италия) различными расстановками с учетом глубины и размеров объекта исследований. Применение геофизических методов позволяет определять различные археологические объекты в соответствии с изучаемым физическим полем, тем самым комплексирование методов дает возможность получить объектно-направленную информацию, при этом не нарушая целостность изучаемых объектов. В результате обработки и интерпретации полевого материала были получены карты, схемы, разрезы и глубинные срезы по геофизическим данным в пределах исследованных площадок с выделением аномалий, которые могут быть связаны с археологическими объектами. Результаты проведенных раскопок, подтверждают достоверность исследований.To date, in world practice, the use of non-invasive geophysical methods in solving archaeological problems is an integral part of the work at the initial stage of research. In the article the experience of using near-surface geophysics on different archaeological sites of Namangan, Djizak and Surkhandarya regions of the Republic of Uzbekistan is considered. The aim of the work was to study ancient burials of kurgan type, to identify cultural layer at the sites of ancient people standing and to study constructions and objects of vital activity of the Kushan period sites in the territory of Northern Bactria. Researches were carried out by the laboratory “Geophysics and nanomineralogy”of the Center of Advanced Technologies by a complex of geophysical methods including magnetic surveying, georadiolocation surveying and electrotomography (ET). The magnetic survey was carried out using Geometrics 856AX proton magnetometers (USA), with a distance of 50 cm between the sensors, so the step between the measurement points and the profiles was 50 cm. GPR measurements were carried out with a PulseEKKO PRO georadar of Sensors&Software company (Canada) using a grid profile system with a step between profiles of 1 m and an antenna with a central frequency of 100 MHz. During the electrical prospecting measurements by ET method a 72-electrode M.A.E. georesistivity meter was used. X-612EM (Italy) was used with different formations taking into account depth and size of the investigation object. Application of geophysical methods allows to determine different archaeological objects in accordance with the physical field under study, thereby the combination of methods makes it possible to obtain object-directed information, while not violating the integrity of the objects under study. As a result of processing and interpretation of field material were obtained maps, diagrams, sections and depth sections on geophysical data within the investigated sites with the allocation of anomalies that may be associated with archaeological objects. The results of the excavations, confirm the reliability of the research.

Application of Geophysical Survey Methods in Projects for the Elimination of Objects of Accumulated Environmental Damage

The analysis is carried out and the relevance of the application of geophysical methods for the elimination of objects of accumulated environmental damage is shown. The conclusion is made about the effectiveness of the proposed methodology, which provides a reduction in the duration of engineering surveys, as well as the cost of PIR by 1.5 times compared with traditional methods.

Origin of block accumulations based on the near-surface geophysics

AbstractUnderstanding the internal structure of specific landforms is a crucial prerequisite for determining their origin and evolution. Near-surface geophysics represents a non-invasive way of subsurface investigation, and it can be used to describe subsurface conditions, especially in protected areas. We tested possible hypotheses of block accumulations origin and evolution by four different geophysical methods (electrical resistivity tomography [ERT], shallow seismic refraction [SSR], ground penetrating radar [GPR], and electromagnetic induction [EMI]) in the Central European Uplands. At the same time, we evaluated the applicability of geophysical methods to determine the internal structure and thickness of block accumulations. Based on the application of two suitable methods (ERT and SSR), we (1) estimated the thicknesses of block accumulations, (2) partially described their internal structure, and (3) presented the most probable hypotheses of block accumulation origin and evolution in two investigated sites.

Застосування методів радіолокаційної інтерферометрії та георадарного знімання для моніторингу земель історико-культурного призначення

Goal. The purpose of the work is to consider the application of geophysical methods for local areas (satellite radar interferometry and ground-penetrating radar surveying) in determining the boundaries of lands of historical and cultural purpose. Method. A combination of methods for identifying or clarifying the boundaries of historical and cultural heritage objects for the establishment of protective zones is proposed. This combination includes two methods of determining or monitoring lands of historical and cultural purpose, namely satellite radar interferometry and ground-based GPR surveying. With the help of satellite radar interferometry, it is possible to determine vertical displacements of the earth’s surface, that is, subsidence of soils in places where there are possible elements of cultural heritage objects (underground passages or underground rooms on the territory of castle complexes, places of mass graves, etc.). After determining the locations of the largest vertical displacements of the soil, these areas are investigated by ground-penetrating radar for the detection of anomalies, which are subsequently deciphered. With the help of a combination of these methods, it is possible to identify additional elements of objects of historical and cultural heritage located underground without archaeological intervention. This allows clarifying the existing boundaries of lands of historical and cultural purpose or discovering new ones, which in turn affects the correction of protection zones. The results. As a result of the research, two examples of the discovery of new lands of historical and cultural purpose using a combination of satellite radar interferometry and georadar surveying in the village of Nitishyn and the village of Bryukhovychi are presented. These lands of historical and cultural purpose include mass graves from the time of the Second World War, the boundaries of which have been clarified using these methods, which serves as the basis for establishing protective zones. Practical value. The obtained results of the application of the methods of radar interferometry and ground-penetrating radar surveying in the study of objects of historical and cultural purpose can be used to clarify the boundaries of the land plots of the corresponding fund. It is more accurate to adjust the security zones according to the received border results.

Capacitive Resistivity Method Applied to the Environmental Diagnosis and Management of Contaminated Area of Gas Station

This article presents a case study of fuel underground contamination where the geophysical method was applied to support for decision making regarding environmental management activities. The application of geophysical methods that measure electrical resistivity in the study of contaminated areas and their correlations with organic contaminants are discussed, in addition to the presentation of theoretical and practical aspects of Capacitive Resistivity (CR) method. The importance of this work is based on the evaluation of the potential for identification of free phase of organic contaminant by the capacitive method and the assessment of the effectiveness of the remediation implemented through the geophysical data obtained. The method applied was able to identify the highest electrical resistivities related to fuel in the subsurface and indicated the inefficiency of the current remediation by the inadequate positioning of the extraction wells and the inaccuracies in the monitoring of underground contamination and allowed the proposition of recommendations related to management of the case based on geophysical information. From results, it is concluded that the Capacitive Resistivity method can be applied in similar cases of leaks in gas stations to diagnose contamination and to guide the adoption of more appropriate actions of environmental management.

Application of geophysical methods in environmental monitoring

Application of geophysical methods in environmental monitoring

IAG/USP Test Site: A Near Surface Geophysics Teaching and Research Laboratory

This work shows the construction project of the Geophysical Test Site (Sítio Controlado de Geofísica Rasa, SCGR-I) of the Institute of Astronomy, Geophysics and Atmospheric Sciences (IAG), of the University of São Paulo (USP) and its impact on teaching and research in Geophysics. The IAG/USP test site (SCGR-I) has 1500 m2, being characterized by 7 studies lines with 30 m length in the NS direction. Targets, such as metallic pipes and tanks, plastic pipes and tanks, concrete tubes, ceramic pots, among others, with different geometries and physical properties were buried at depths from 0.5 to 2 m in relation to the surface. A metallic guide pipe of 3.8 cm diameter was buried at the 15 m position along the EW direction, crossing all 7 lines. Targets simulate objects found in archaeological studies, geotechnical and urban planning studies and environmental studies. In this work, comparative analyzes between real and synthetic GPR results on metallic and plastic tanks are shown, as well as EM38 results on metallic tanks. The SCGR-I proved to be an important tool for teaching and research related to the applications of geophysical methods for near surface investigations and could be a motivation to build more test sites.

Geophysical data fusion of ground-penetrating radar and magnetic datasets using 2D wavelet transform and singular value decomposition

This work addresses the problem of the lack of perceptibility that geophysical data may have. Data fusion allows us to combine datasets, providing an improved and more informative source of information about structures buried in the ground. After testing different approaches, a strategy was developed using ground-penetrating radar and magnetic datasets collected over the same area. Data collected at the Roman Villa of Pisões (Beja, Portugal), which is a place of easy application of geophysical methods, were used to test the method, but with problems caused by the properties of the soil. The approach was based on processing operations that allow the fusion of images obtained by different equipment widely used in medical imaging for tumor detection and image processing. The goal is to create an improved image with data fusion that has higher quality than the input images, allowing a better understanding of the object of the study. The approach is composed of two stages: pre-processing and data fusion. Pre-processing is applied to enhance the input data. It consists of removing background noise through singular value decomposition applied in the spectral domain. Then the calculation of the data entropy will highlight the differences corresponding to the spatial alignments compatible with buried structures. Then, both entropy maps of the two datasets are fused in the second processing step to produce the final image. This step involves applying the 2D wavelet transform to each entropy map, decomposing them into sub-bands. Algorithms to calculate multiresolution singular value decomposition and the image gradient are applied to the sub-bands. The processed sub-band pairs are then fused using specific fusion rules. The fused image is obtained by applying the inverse of the wavelet transform. Data fusion with the proposed approach allows us to obtain a detailed image that is sharper and of better quality than the input datasets. The increase in sharpness and quality can be quantified through the sharpness index and the BRISQUE quality index in several steps of the processing. The obtained values confirm the graphical results. Images produced by the proposed data fusion approach suggest that the perceptibility has increased, allowing us to provide conclusions about the existence of buried structures.

The 75th Anniversary of Professor Vladimir V. Filatov Essay on scientific and educational activity

The article focuses on scientific and educational activity of Vladimir V. Filatov, DSc in Geology and Mineralogy, Professor, professor of the Vladimir State University, and a specialist in exploration geophysics. The Professor’s research is devoted to the development of theory, methodology and practical application of geophysical methods for mineral prospecting and exploration, geological mapping, the study of urban geoenvironment tectonic structure and dynamic behaviour and forecasting hazardous dynamic events in urban areas. A brief biography and main results of scientific work are provided.

A Systematic Review of the Relationship between Geotechnics and Disasters

Landslides, earthquakes, and other natural events can change the landscape and generate human and economic losses, affecting transportation and public service infrastructure. In every geotechnical project, the investigation phase plays a fundamental role in reducing the risk of occurrence and mitigating catastrophes. As a result, governments have created entities to study disasters and identify triggering factors that generate huge losses worldwide. This research aims to conduct a systematic review of the relationship between geotechnics and disasters through bibliometric techniques, scientific production evaluation, and case studies analysis to recognize key topics, methods, and thematic development of the research worldwide. The research methodology consisted of three steps: (1) Database analysis, selection, and combination, (2) bibliometric analysis, and (3) systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. The systematic review with bibliometric analysis collected data from 1973 to 2021, with 1299 academic publications indexed in the Scopus and WoS database. These results indicated a growing trend of annual publications on disasters and their relationship with geotechnical studies, highlighting current issues and technological innovation. The main research trends in disaster risk assessment were topics mainly linked to landslides, earthquakes, liquefaction, and inappropriate analysis models with applications of geophysical methods, laboratory tests, remote sensing, and numerical models.

Comprehensive Geophysical Measurement in Seismic Safety Evaluation: A Case Study of East Lake High-Tech Development Zone, China

Wuhan East Lake High-tech Development Zone is a National Innovation Demonstration Zone where several major projects are under construction. For the seismic safety evaluation of the zone, it is urgent to find out basic data such as stratigraphic structure, geometric characteristics of buried faults, and overburden thickness. In this study, seismic reflection and microtremor surveys are adopted in seismic safety evaluation in urban areas for the first time. Combined with borehole data, the overburden thickness and buried faults in the target area are detected and analyzed. The results are as follows: ① The seismic reflection detection is carried out for the possible hidden locations of the Xiangfan-Guangji Fault and Macheng-Tuanfeng Fault in the target area, and the obtained high-resolution seismic reflection profiles can be used to precisely divide the stratigraphic structure and preliminarily find out the geometric characteristics such as the strike, tendency, and the buried depth of the upper breakpoint of the buried faults. ② A microtremor survey is carried out in key regions of the target area, and the obtained velocity structure imaging can provide a perspective window into the urban underground space structure and accurately determine overburden thickness and the depth of strongly and moderately weathered bedrock. Comprehensive geophysical measurements can better realize the acquisition of basic data such as the stratigraphic structure of complex regions and characteristics of urban buried faults, which provides an important basis for seismic fortification. At the same time, the combined application of geophysical methods avoids the detection of the blind area and provides a guarantee for urban safety and sustainable development. Furthermore, the study has reference value for seismic safety evaluation in similar areas of the world. If comprehensive geophysical measurement can be popularized, its economic and scientific value will be immeasurable.

Application of Geophysical Methods in Archaeological Survey of Early Medieval Fortifications

As powerful economic and cultural centers, fortified sites played an important role in early medieval society. In Central Europe, early medieval fortified site research has been an essential topic for several generations. However, gradual changes in the landscape are a threat to these cultural heritage monuments. The main task of this paper was to compare the previous results from archaeological excavations with new data acquired by geophysical methods. The presented study is based on the three methods widely used in archaeology: magnetometry, ground-penetrating radar, and electrical resistivity tomography. New surveys provide information about the internal structure and the state of preservation of the fortifications in a non-destructive way. Comparison of the results encourages the evaluation of archaeological excavation and helps determine the suitability and effectiveness of geophysical methods in specific natural conditions.