Geophysical Research Research Articles

High Water Levels Cause Problems for Mississippi Shipping

Source: Geophysical Research LettersDroughts’ effect on the navigability of rivers is well documented: During the summer and fall of 2022,.

Seismic Soundoff: How the SEG Foundation makes a difference

David Bartel, chair of the SEG Foundation, shares how the nonprofit organization is advancing geophysics research, supporting SEG members, and positively impacting society.

Processing and re-interpretation of gravity bouguer map of a selected area in the W-NW of Iraq

Geophysical data interpretation is crucial in characterizing the subsurface structure. The Bouguer gravity map analysis of the W-NW region of Iraq serves as the basis for the current geophysical research. The Bouguer gravity data were processed using the Power Spectrum Analysis method. Four depth slices have been acquired after the PSA process, which are: 390 m, 1300 m, 3040 m, and 12600 m depth. The gravity anomaly depth maps show that shallow-depth anomalies are mainly related to the sedimentary cover layers and structures, while the gravity anomaly of the deeper depth slice of 12600 m is more presented to the basement rocks and mantle uplift. The 2D modeling technique was used for the quantitative interpretation of a selected Gravity profile along the study area. The model section of the gravity profile illustrated the relatively high density of subsurface basement rocks and/or upward mantle process which causes the effect of positive gravity values. Furthermore, several faults are indicated in the sedimentary sections by potential gravity methods such as several grabens, half grabens, and horst structures which are identified in Bouguer depth maps by relatively high and low gravity values, these structures were also affected by the basement rock uplift and/or Mantle upwards.

Глубинные сейсмические исследования МОВ ОГТ на государственных опорных геолого-геофизических профилях

The main concept of reference geological and geophysical profiles is to obtain a holistic picture of the structure of the crustal section of large mineragenic provinces. Modern geological and geophysical research on profiles is complex. In addition to seismic observations of the DSS-SMRW, the use of materials from gravimetric and magnetometric surveys, the mandatory use of magnetotelluric soundings (AMT, MT and DMT), they include deep seismic work RS-CDP (method of reflected waves in the modification of the common depth point), which is the basic seismic method based on recording near-vertical reflected waves.

Geophysical research on a landslide-prone slope in the vicinity of the village of Ayusay in the Republic of Kyrgyzstan

This article presents geophysical studies in the area of the village of Ayusay. The impact of landslides on the economy, climate and ecology of the region is described. Geophysical and topographic surveys for protecting the region from landslides and mudflows are presented. The physical and geographical characteristics of the study area are described. A topographic survey was performed with a Trimble M3 tacheometer at a scale of 1:1000 with a relief section of 1.0 m. The results of geodetic measurements were processed in the standard CREDO software. Tectonic changes over time are analyzed. Physical and geological phenomena and processes with the formation of cracks are studied in detail. The hydrographic network is described, which is represented by the Ayusay Creek and its lateral components.To control the dynamics of slope masses along the studied section of the slope, marks and benchmarks are installed. A set of measures to prevent or reduce the risk of landslides is presented.

Application of ground-penetrating radar for shallow subsurface investigation at the coastal area of lhok village, lhoong, aceh besar regency, aceh

This research aims to identify subsurface layers in the coastal area of Lhok Village, Lhoong, Aceh Besar Regency, Aceh. Ground Penetrating Radar (GPR) was the primary method to extract information concerning concealed geological structures beneath the Earth's surface, including in coastal areas. GPR is a non-destructive geophysical technique that utilizes electromagnetic waves to explore and map subsurface layers. However, data collection involved field surveys utilizing GPR equipment directed at the ground's surface. During the survey, radar data was processed and analysed to pinpoint various subsurface level. The obtained information contributes to a deeper understanding of the region's geological characteristics and subsurface layers. Additionally, it aids in assessing geological risks, facilitating construction planning, and conserving natural resources in the area. Here, the outcomes of this study may also serve as a foundation for further research in geology and geophysics within the Aceh Coastal region.

Перспективы использования инженерно-геофизических методов на гидроузле реки Ирелях (Западная Якутия)

The construction of hydraulic structures in the permafrost zone leads to the formation of local sources of hydrogenic thawing. The process of formation and expansion of subchannel natural-technogenic talics requires permanent study and monitoring, including the use of new and adaptation of existing methods of engineering geophysical research. The paper examines the results of engineering geophysical surveys aimed at studying the actual engineering, technical and cryohydrogeological state of the drinking water reservoir on the Irelyakh River. The scope of the work included following methods: electrical profiling, natural potential, vertical electrical sounding, dipole sounding, and thermometry. Based on the results of the study, it was determined that the natural-technogenic talic in the terrigenous-carbonate rocks at the base of the reservoir currently continues to develop. Continuous development in the infiltration zone, as well as at the discharge front and observed flow rates has been observed. The thickness of the thawed rocks in the upper reaches of the river, according to the results of geophysical data, does not exceed 20 m, and in the lower reaches of the dam is already at least 100 m. The dynamic nature of the development of the object under study requires continuous engineering and geophysical monitoring to be carried out on a regular basis.

THE STATISTICAL SIMULATION OF DATASET IN 3D AREA WITH "CUBIC" СОRRELATION FUNCTION ON EXAMPLE RIVNE NPP GEOPHYSICAL MONITORING

Background. The model and algorithm were developed by using optimal in the mean square sense "cubic" correlation function. An example of supplementing the results of geophysical studies of karst-suffuses phenomena with simulated data in the task of monitoring the density of the chalk stratum on the territory of the Rivne NPP is presented. The complex geophysical research was conducted on Rivne NPP area. The monitoring observations radioisotope study of soil density and humidity near the perimeter of buildings is of the greatest interest among these. In this case a problem was occurred to supplement simulated data that were received at the control of chalky strata density changes at the research industrial area with use of radioisotope methods on a grid that included 29 wells. This problem was solved in this work by statistical simulation method that provides the ability to display values (the random field of a research object in 3D area) in any point of the monitoring area. Methods. Based on the spectral decomposition of random fields in 3D space, a statistical model of the distribution of the average density of the chalk layer in the 3D observation area was built. Results. An algorithm for statistical simulation of random fields with a "cubic" correlation function is formulated. On the basis of the developed software, additional simulated realizations of the random component of the research subject on the grid of observations of the necessary detail and regularity were obtained. A statistical analysis of the results of the numerical simulation of the distribution of the average density of the chalk layer was carried out and their adequacy was tested. Conclusions. The method of statistical modeling of random fields with "cubic" correlation functions allows you to supplement data with a given accuracy.

Analysis of the causes of flooding of long-term deposits under conditions of high geological heterogeneity

In this work, the object of research was the long-term deposits of liquid hydrocarbons located within the boundaries of fields with high geological heterogeneity, the proportion of which is actively increasing every year due to the selection of a significant part of the “light” oil reserves. Based on the generalization of the results of direct and indirect research on the topic of the work, the key causes of well flooding were identified and their primary sources were identified, which made it possible to successfully describe the mechanisms of formation of the transition zone of the oil-water system, depending on the stage of development. The conclusion is made about the importance of applying relevant and reliable scientific and methodological approaches in interpreting the results of geophysical research to solve various problems of oil field development.

Дослідження моделей та алгоритмів систем локалізацій джерел магнітних аномалій

Introduction. The application of modern geophysical methods are caused by the challenges of nowadays Ukraine standing with. The high efficiency of geophysical research is shown by the methods of magnetic exploration. Method of analyzing the array of data from the magnetometer is used to localize the magnetic anomaly’s sources. Such localization is implemented by using various mathematical models and algorithms of software systems. Purpose. The aim of the article is to show an overview of mathematical models and algorithms for the localization of magnetic anomalies’ sources (disturbances). They allow to speed up the processing of magnetometric research’s data and visualize the obtained results. Methods. The article examines the mathematical models of the magnetic anomaly< such as magnetic dipole model, the Gaussian model, the Schwartz model. The multilayer model, and also provides the overview of the main methods for the localization of the described anomaly – the filtering method, the least square method, the gradient analysis method. A list of software and online resources is given, this software is used to analyze magnetometer data and locate magnetic anomalies’ sources. Results. Four mathematical models of magnetic anomalies that allow describing objects of various configurations are considered in the article, and the main methods of determining these objects in the magnetometer data array are given. The article presents the most popular software used for magnetometric data processing. Most of the software is used in geophysics for deep research and requires significant computing resources. A software application was proposed and developed. It allows importing data from the moving platform and magnetometer, analyzing data and visualizing the results. Conclusion. The results of the review emphasize the importance of improving existing mathematical models and developing specialized software for magnetic anomalies’ source localization.

Flow Profile Estimating in production wells based on chemical composition of fluids (an example on Volga-Ural Petroleum and Gas Province)

Current problems in mature oil fields are high water cut and flow profile estimating of oil and associated brines from different layers. To establish the flow profile in production wells, geophysical research (Production Logging) is traditionally used by lowering special equipment into the well. Production Logging requires production stops and labor costs. Geochemical methods (Production Geochemistry) are used as an alternative solution: sampling is simple and efficient, which makes it possible to cover all the interesting area. Moreover, sampling does not require stopping the well. The geochemical method uses individual indicators of the composition of formation fluids produced from different perforation intervals. In this work, geochemical studies were carried out using wellhead samples from more than 100 wells, with single perforation for carbonate and terrigenous reservoirs. Some wells have joint exploitation of these formations. An automated algorithm was used to identify the distinctive characteristics of each formation based on the composition of the produced brines and oils. Data on the chemical composition of fluids from different development objects made it possible to determine the flow profiles in wells with joint production. Based on the results of the studies, the Devonian reservoir of the field under consideration is divided into 2 parts – northern and southern, which differ in the chemical composition of formation fluids. The same separation of the deposits into 2 parts is noted by field development analysis: over the past 50 years, the main production of oil and associated brines has been concentrated in the southern part of the deposit, confined to the fault, where the active work of the aquifer is assumed. It is recommended to use the obtained data for history matching of the reservoir simulation model.

ПАМЯТИ ВАЛЕРИЯ МИХАЙЛОВИЧА ЮБКО (19.05.1950–01.06.2022)

The article is dedicated to the memory of Valeriy Mikhailovich Yubko, Honored Geologist of the Russian Federation, Doctor of Geological and Mineralogical Sciences, an outstanding specialist in the field of marine geological and geophysical research and the geology of oceanic solid minerals – ferromanganese nodules and cobalt-rich ferromanganese crusts of the World Ocean, who headed the geological service for 15 years State Scientific Center JSC (until 2016 FGUGP) “Yuzhmorgeology”, and in recent years acting as the Scientific Secretary of the State Scientific Center. The article presents biographical data, highlights the scientific achievements and personal qualities of V. M. Yubko.

Computer Modeling of the Electrical Conductivity of the Geological Environment in Problems of Monitoring the Reliability of the Foundation of Roads, Buildings and Engineering Structures

Main problem: Monitoring the reliability of the foundation of roads, buildings and engineering structures is an important aspect of geophysical research. Modeling of geological heterogeneities is relevant. Moreover, the use of computer modeling in this problem is associated with computational costs. Purpose: Analysis of the vertical electrical sounding (VES) method for modeling the physical properties of soil and their changes when exposed to elastic vibrations. Methods: To achieve the goal, the vertical electrical sounding (VES) method was used, using a one-dimensional model of the geological environment. The direct VES problem was solved by calculating the Hankel integral. Results and their significance: The study made it possible to model a large number of soil layers using the VES method. The results obtained make it possible to determine the parameters of detected objects and changes in the characteristics of the controlled environment when exposed to elastic vibrations. The significance of the results lies in the possibility of improving the method for modeling the physical properties of soil and taking into account their changes under the influence of elastic vibrations, which helps to increase the efficiency and accuracy of monitoring the reliability of the foundation.

Hydrothermal fluid circulation within the restless structural frame of Hasandağ volcanic system (Central Anatolia, Türkiye) inferred from Self-potential, CO2, and temperature measurements

Hasandağ is an active composite volcanic system located in the Central Anatolian Volcanic Province (CAVP). A comprehensive field survey was conducted to reveal the hydrothermal activity within the Hasandağ volcanic system, with particular emphasis on Self-Potential (SP) mapping. The Hasandağ system is characterised by the presence of twin stratovolcanoes that arise from pre-existing partially buried calderas. In conjunction with the SP measurements, carbon dioxide concentration (CO2) and surface temperature (ST) measurements were taken. The temperature measurements were elaborated with thermal infrared remote (TIR) sensing methods. The SP results, with a peak-to-peak magnitude of 3.8 Volts, revealed the presence of a significant hydrothermal input in both of the twin cones, characterised by a typical W-shaped anomaly commonly observed in active volcanoes. The highest SP signal coincides with the active fumarole zone at the western flank of G. Hasandağ summit, where we measured ∼70 °C vapour temperatures and relatively high CO2 output (>100,000 ppm). The SP/elevation (Ce) gradient assisted in revealing the hydrothermal and hydrogeological zonation, providing substantial evidence of the relationship between hydrothermal circulation and the structural frame of the volcano. Integrated evaluation of SP, CO2, and temperature data revealed the structural control on the hydrothermal and hydrogeological circulation, with the contribution of Hasandağ, Karacaören, and Karkın Faults as major structural components. The partially buried rim of the Hasandağ caldera was revealed through the detection of a ‘double Ce-low’ signal, providing valuable insights on the dimensions of the structure and its role in the hydrogeological cycle of the system. The extent and magnitude of the hydrothermal activity observed, the Holocene eruptive history of the volcano, and its proximity to populated areas denote the requirement of further geophysical and geochronological research and the necessity of hazard assessment and instrumental monitoring.

Groundwater and its detection by geophysical methods (Review)

The world, including Iraq, suffer from the opportunity to obtain water sources, involves groundwater which is necessary for daily uses, agriculture and industry, it face many problems of environmental pollution, climate changes and the increasing in demand due to growth in population .Groundwater is a source that present inside the voids and fractures in the rocks and various soils under the surface of the earth forming water reservoirs which can be investigated and detected to be used later to satisfy the needs of humanity. Geophysics is a branch of geological science, it based on the theories of physics and their applications to detect the materials that make up the earth, including groundwater, so it is necessary to explain the foundations of the different methods necessary for those working in this field, geophysical research representation especially those who conducted electromagnetic, electrical and self-potential methods have proven that they are good and effective in detecting the locations, distribution and depth of groundwater.

Unveiling a hidden fortification system at “Faraglioni” Middle Bronze Age Village of Ustica Island (Palermo, Italy) through ERT and GPR prospections

We carried out a geophysical research project in the Middle Bronze Age village of Ustica (Palermo, Sicily, Italy), named “Faraglioni Village” after the stack formations which detach from the coast north of the archaeological site. The investigation, which comprised Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR) techniques, allowed us to discover the buried foundations of an outwork fortification system never evidenced by previous archaeological studies, only hypothesised from the observation of aerial photography and partially outcropping boulders, which align roughly parallel to the main defensive wall of the Village.Our geophysical prospection involved the entire 250 m-long arc of the outward village defensive wall, with the acquisition of eleven ERT profiles and 27 GPR scans. The techniques were selected based on both favourable logistics and methods applicability: ERT sections allowed us to trace a series of high-resistivity anomalies arranged to form an arc-shaped structure along the perimeter of the defensive wall. GPR investigation was localised in the most accommodating patch of terrain of the site, with the effort of intercepting clear enough sections of the target, to determine more accurately its shape, depth, and overall dimensions. Our discovery paves the way for new investigations, mainly aimed at defining the timing of construction of the fortification system, as well as the function of the remains of other architectural structures identified close to the wall, which could represent the target of further geophysical investigations.

Computer modeling of the interaction of the building underground part with the soil foundation during the karst cavity formation on the example of the administrative and business center construction

In restrained urban conditions of Moscow, the accomplishment of complex urban construction projects is complicated by the choice of construction sites, as well as by lack of methods for computer modeling of the interaction of high-rise and unique buildings and structures with the probable formation of karst cavities in the current regulatory documents. The overall profitability of the project is under the great impact of it, therefore a reliable accounting of karts-suffusion processes is a priority issue in designing buildings and structures, especially if it concerns the unique and high-rise ones. The authors analyze the results of the calculations of the forecast assessment of the impact of a karst cavity probable formation on the subsurface parts of building of the administrative and business center construction in flat and spatial formulation. In spatial formulation different positions of the potential karst cavities are considered; their locations were chosen according to standard procedures and were guided by the results of geological and geophysical research. It has been reviewed the formation of arch over a karst cavity in a 2D and 3D formulation in the condition of different location of the karst cavities in plan and by depth of occurrence. It has been made methodological recommendations for determining the predicted bore of the karst cavity, for taking into account the frame stiffness of the aboveground part of the building, for defining the principles of a karst cavity modeling, as well as for the choice of assessment criteria of stability of cover mass above the potential cavity. The discovered differences in the results of 2D and 3D settings permit to make a conclusion that solving the problem in a flat formulation contributes to the overestimation of karst processes danger and, therefore, to the excess in anti-karst measures included in the project.

SEISMICITY of KAZAKHSTAN and ADJACENT TERRITORIES in 2018–2019

In 2018–2019, the seismic monitoring in Kazakhstan was conducted by the Seismological Experience-Methodical Expedition of the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan and the Republican State Enterprise «Institute of Geophysical Research of the Ministry of Energy of the Republic of Kazakhstan». The paper presents detailed information on seismic observation networks. The joint catalogue based on the data of two organizations was compiled. It includes 1050 earthquakes with energy class KR=6.6–12.8. The strongest earthquake within the considered territory occurred on February 1, 2019, KR=12.8, MPVA=5.6, Mw=5.0. Its epicenter was located on the territory of Xinjiang (China), near the Kazakhstan-Chinese border. The earthquake was felt in numerous settlements in Kazakhstan. On so-called “Northern Tien Shan” territory, the strongest earthquake occurred on March 26, 2018, KR=12.0, MPVA=5.5, the epicenter was near Kapchagay water basin on the territory of Iliy depression. For the period 2018–2019, on the territory of Kazakhstan there were induced and natural-induced earthquakes at the west, central, and east Kazakhstan. In whole, the period of 2018–2019 was characterized by moderate seismicity for the major part of the country’s territory.

Geophysical research on the interplays between soil–rock variability and hydrogeological structures: a case study

Understanding the spatial variations in soil–rock profiles is crucial for identifying weathered rock layers and mapping geological structures, particularly in the complex feldspar-rich granitic terrain of Penang Island, Malaysia. This study employs a combination of electrical resistivity and seismic refraction tomographic techniques, along with borehole lithological data, in three distinct areas on the island. Its goal is to provide insights into surficial and subsurface soil–rock characteristics and water-bearing structures within the North Penang Pluton (including a part of the Sungai Ara axis) for sustainable groundwater development, addressing the needs of the region's growing population. The research identifies three distinct geological units at the near-surface: residual soils, highly to moderately weathered/fractured granitic layers and fresh bedrock, each with its hydrogeological properties. Promisingly, the weathered layers offer significant groundwater development potential, with deep weathered and potentially fractured zones exceeding depths of 30 m in the study area. These findings have substantial implications for sustainable groundwater development, especially in tropical hard-rock terrains. In addition, the study underscores the limitations of small geophysical spacings when probing deeper groundwater resources. This knowledge is essential for informed decision-making in water resource management and infrastructure development, addressing the ongoing global challenge of ensuring access to clean water resources amid population growth.

Features of forecasting abnormally high reservoir pressures when drilling wells in areas of south-western Turkmenistan

Introduction: The study is essential because predicting areas with high formation pressures in geophysical research is complex. It requires new technologies to accurately locate them and minimize unforeseen emergencies. The purpose of this study is to analyse and identify the peculiarities of predicting anomalously high formation pressures during well drilling in the territory of south-western Turkmenistan in order to provide more effective and reliable pressure management during drilling and operation. Materials and Methods: Methods such as analysis and prediction were used in this study. Results and Discussion: The paper presents valuable research data highlighting the changes in reservoir pressure gradients in the unique stratigraphic section of reservoirs in the oil and gas fields of the Pribalkan and Gogerendag-Ekerem zones. The analysis of the studies reveals the dynamism with which the properties of reservoir rock change with increasing depth of occurrence. Special attention is paid to the processes associated with the formation of anomalously high formation pressures, which is an important aspect for understanding complex geological processes. Conclusions: The study provides a detailed classification of formation pressures, considering the anomaly coefficient, enhancing our understanding of this phenomenon. Predicting formation pressures for specific horizons relies on analyzing deep well drilling results.