Acta Geophysica最新文献

{"title":"Estimation of Curie-point depth, heat flow and geothermal gradients in Shelleng area and environs, northeastern Nigeria from aeromagnetic data","authors":"Hassan Nelson Yassah,&nbsp;Kalu Mosto Onuoha,&nbsp;Ayonma Wilfred Mode,&nbsp;Kamureyina Ezekiel,&nbsp;Eze Martins Okoro","doi":"10.1007/s11600-024-01352-0","DOIUrl":"10.1007/s11600-024-01352-0","url":null,"abstract":"<div><p>Regional estimation of Curie-point depth (CPD), subsurface heat flow and geothermal gradients variations in the Shelleng area and environs of northeastern Nigeria was carried out in this study using spectral analysis of high-resolution aeromagnetic (HRAM) data. The HRAM data were divided into nine (9) overlapping blocks and each of the blocks was analyzed to obtain the 2D radially averaged power spectrum which enabled the computation of depths to the top and centroid of magnetic sources. The obtained values were then used to determine the depth to the bottom of magnetic bodies or the CPD, geothermal gradients and crustal heat flow changes in the study area. Results showed that CPD varies from 7.56 ± 0.122 to 18.01 ± 0.324 km, with an average of 11.72 ± 0.166 km; geothermal gradient values vary between 32.20 and 76.72 °C/km, with an average of 52.76 °C/km, while heat flow variations range from 80.51 to 191.80 mW/m², with an average of 131.85 mW/m². Shallow CPD zones identified in the northeastern, western and southwestern portions of the study area correspond to zones of high geothermal gradient values and high subsurface heat flow distributions. These areas signify zones associated with anomalous subsurface thermal conditions and were therefore recommended for further detailed geothermal energy exploration studies.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"73 1","pages":"203 - 220"},"PeriodicalIF":2.3,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141109875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A method for tight gas reservoir evaluation based on nuclear logging","authors":"Xinyue Fu,&nbsp;Wensheng Wu,&nbsp;Bowen Sun,&nbsp;Mingsong Wu,&nbsp;Hu Wang,&nbsp;Yunlong Ge","doi":"10.1007/s11600-024-01373-9","DOIUrl":"10.1007/s11600-024-01373-9","url":null,"abstract":"<div><p>Tight gas reservoirs with low porosity and low permeability can encounter problems such as small dynamic range of measurement information and low log-response sensitivity, which make it difficult to accurately identify gas reservoirs and evaluate gas saturation. The purpose of this paper is to improve the accuracy of tight gas reservoirs evaluation by combining different nuclear logging methods. Slope, a parameter based on thermal neutron cross section and density, is proposed to improve the accuracy of tight gas reservoirs evaluation. The Monte Carlo method is used to analyze the sensitivity of different nuclear logging parameters to gas-bearing formations. The effects of various environmental factors on slope calculation results are analyzed. The applicability of the proposed method in synthetic models and field data is analyzed to verify its effectiveness. The results show that the sensitivity of the slope-based method to gas in low-porosity formations is much higher than that of other methods. Shale content has a minor impact on slope. Lithology and gas density affect slope calculation results. Salinity has little effect on slope in low-porosity formations. The data interpretation results from the field well show that the accuracy of gas saturation calculation of the slope-based method is much higher than that of the Archie formula-based method. The proposed method can provide strong support for the effective exploration and development of tight gas reservoirs.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"72 6","pages":"4295 - 4305"},"PeriodicalIF":2.3,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141118148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined electrical resistivity tomography and high-resolution shallow seismic analysis for coal exploration in Talcher Coalfield, India","authors":"Arvind Yadav,&nbsp;Thinesh Kumar,&nbsp;Anurag Tripathi,&nbsp;Sanjit Kumar Pal,&nbsp; Shalivahan","doi":"10.1007/s11600-024-01349-9","DOIUrl":"10.1007/s11600-024-01349-9","url":null,"abstract":"<div><p>Talcher Coalfield is one of the most important coalfields considering thermal grade coal reserves in India; nevertheless, hardly any published geophysical study is available for mapping the subsurface coal, in-crop zone, fault location, formation boundary, etc. In the present study, a combined analysis of electrical resistivity tomography (ERT) in five profiles and high-resolution shallow seismic (HRSS) survey in two profiles was carried out in Goribandh at the northern–eastern part of the Talcher Coalfield, Odisha, India, to study the structural control of coal seams and to delineate the coal potential zone and non-coal zone. Geological core data from three boreholes were utilized to validate the ERT and HRSS results. Three ERT profiles (ERT_P1, ERT_P2, and ERT_P3) data were acquired in perpendicular to the strike direction, and two ERT profiles (ERT_P4 and ERT_P5) data were collected in the strike direction. The purpose of the acquisition of ERT data in the strike direction is to correlate the resistivity values at the cross point of dip lines and strike lines. Two HRSS profiles (HRSS_P1 and HRSS_P2) data were collected along the same two corresponding dip lines of the ERT profiles (ERT_P1 and ERT_P2). The ERT data were collected using Wenner–Schlumberger array at 10 m electrode spacing with multiple roll-along sequences to cover the desired profile length with an approximate profile line spacing of 200 m. The Res2Dinv program was used to execute the inversion of the combined data set. The HRSS data were acquired by ‘End-on-Shooting’ method using 24-fold common depth point survey at 4 m geophone spacing with multiple roll-along sequences to cover the desired profile length with approximate profile line spacing of 200 m, where near trace and far offsets trace were 88 and 276 m, respectively. HRSS data were analyzed using Paradigm 19 seismic processing software. Comprehensive analysis of five numbers of 2D ERT sections (ERT_P1-ERT_P5) and two numbers of HRSS sections (HRSS_P1 and HRSS_P2) indicates that the southern part of the study area is characterized by relatively low to moderate high resistivity (100–500 Ωm) distribution while seismic sections demonstrate multiple strong reflecting horizons, due to carbonaceous beds as identified in the boreholes, indicating Barakar formation. The northern part is characterized by high resistivity (200–1000 Ωm) distribution, while seismic sections exhibit multiple distributed minor reflectors due to boulder beds and or compact sandstone. The combined study of ERT and HRSS data delineates a prominent fault zone F4, indicating a contact boundary between the Talchir and Barakar formations.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"72 6","pages":"4263 - 4293"},"PeriodicalIF":2.3,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141059214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into saline soil cracking subjected to drying-wetting cycles","authors":"Haoxuan Feng,&nbsp;Xuguang Xing,&nbsp;Liuchang Su,&nbsp;Chunzhe Zhang,&nbsp;Yubo Wang,&nbsp;Yibo Li,&nbsp;Weihua Wang","doi":"10.1007/s11600-024-01375-7","DOIUrl":"10.1007/s11600-024-01375-7","url":null,"abstract":"<div><p>Soil salinization has become a global environmental issue, and soil cracking can lead to preferential flows and destabilize the developments of plant-soil system. However, little is known about saline soil cracking, especially under external drying-wetting (D-W) alternations. This study explored how soil salt and continuous D-W cycles affected water evaporation and crack development responding to soil salinity (0, 0.3, 0.6, 1.0, and 2.0%, w/w) and three D-W cycles. Observed findings showed that saline soil water evaporation was smaller than nonsaline soil. Besides, the water evaporation decreased and increased as the soil salinity increased and the D-W cycles progressed, respectively. In addition, soil salt and D-W cycle inhibited and promoted soil cracking, respectively; specifically, the crack area density decreased and increased with increasing soil salinity and number of D-W cycles, respectively. Correlations indicated that the soil salt had overall larger contributions than the D-W cycle to the variations of water evaporation and crack development. Soil salt was negatively correlated with cumulative evaporation, evaporation rate, and crack length density, but was positively correlated with soil moisture; besides, D-W cycle was negatively correlated with soil moisture, but was positively correlated with cumulative evaporation, evaporation rate, crack area density, and crack length density. Mechanism exploration suggested that the salts inhibit surface cracking by promoting inter-microaggregate cementation and clay flocculation and blocking soil macropores; and the D-W cycle promotes surface cracking through the swelling-induced crack healing in the case of hydrophilic clay minerals in contact with water.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"73 1","pages":"619 - 633"},"PeriodicalIF":2.3,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141059209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the scenario of urban blue-green space in Tezpur town of Assam using geo-technical approach","authors":"Archita Hazarika, Jyoti Saikia, Sailajananda Saikia","doi":"10.1007/s11600-024-01360-0","DOIUrl":"https://doi.org/10.1007/s11600-024-01360-0","url":null,"abstract":"","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"11 51","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140962320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mesoscale simulation of tropical cyclone Amphan over Bay of Bengal: inter comparison with NCEP and NCUM global models","authors":"Dodda Naga Vyshnavi, P. Raju, Uppu Harish, Raghavendra Ashrit","doi":"10.1007/s11600-024-01368-6","DOIUrl":"https://doi.org/10.1007/s11600-024-01368-6","url":null,"abstract":"","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"8 37","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140964196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the WRF model in reproducing a flash-flood heavy rainfall event over Kosovo","authors":"L. Osmanaj, Irena Spiridonov, B. Jakimovski, Vlado Spiridonov","doi":"10.1007/s11600-024-01365-9","DOIUrl":"https://doi.org/10.1007/s11600-024-01365-9","url":null,"abstract":"","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"2 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140962997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Illuminating groundwater flow modeling uncertainty through spatial discretization and complexity exploration","authors":"Saeideh Samani","doi":"10.1007/s11600-024-01346-y","DOIUrl":"10.1007/s11600-024-01346-y","url":null,"abstract":"<div><p>Uncertainty in groundwater modeling presents a significant challenge, originating from various sources. This groundbreaking study aims to quantitatively assess uncertainties arising from spatial discretization and complexity dynamics. The research focuses on the Najafabad Aquifer in Esfahan, Iran, as a compelling case study. Five distinct conceptual models were developed, with parameter counts of 16 (model 1), 20 (model 2), 22 (model 3), and 26 (model 4 and 5), and subjected to a consistent spatial discretization of 500 m. Additionally, two alternative models with spatial discretizations of 250 m (model 1a) and 1000 m (model 1 b) were introduced based on the least complex model with 16 parameters. The study comprehensively examines groundwater uncertainty by manipulating spatial discretization while considering complexity dynamics. Model Muse facilitates simulation, and UCODE is utilized for calibration using observed hydraulic head data. Uncertainties are explored using Bayesian model-averaging (BMA) and model selection criteria. Comparing probabilities of the initial five models reveals increasing uncertainty with a greater number of parameters (KIC in model 1: 99.25%, model 2: 0.41%, model 3: 0.34%, model 4 and 5: 0%). Investigation of seven alternative models highlights the dominant influence of coarser spatial discretization on groundwater modeling uncertainty. Remarkably, despite the lowest complexity in model 1 with probability of 99.25%, the model with coarse spatial discretization (model 1b) exhibits the zero probability (KIC in model 1a: 93.42%, model 1: 6.53%, model 1b: 0%, model 2: 0.03%, model 3: 0.02%, model 4 and 5: 0%.). Thus, considering optimal parameter count and spatial discretization size is crucial in conceptual model development. This study pushes the boundaries of understanding the intricate relationship between spatial discretization, complexity, and groundwater modeling uncertainty. Findings hold significant implications for improving model accuracy and decision-making in hydrogeological studies.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"73 1","pages":"603 - 617"},"PeriodicalIF":2.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140971183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An integrated workflow for characterizing gas potential: Axios-Thermaikos basin (Greece)","authors":"Konstantinos Chavanidis,&nbsp;Dicky Harishidayat,&nbsp;Alexandros Stampolidis,&nbsp;Grigorios N. Tsokas,&nbsp;Ahmed Salem,&nbsp;Pantelis Soupios","doi":"10.1007/s11600-024-01358-8","DOIUrl":"10.1007/s11600-024-01358-8","url":null,"abstract":"<div><p>The Axios-Thermaikos basin in northern Greece is a sedimentary composite depocenter that developed tectonically during the Neogene. It has been considered promising for hydrocarbon resources, with a proven offshore gas field. Several geological and geophysical surveys, including drilling, were conducted in previous decades. However, a complete model of the basin subsurface has yet to be constructed. This paper seeks to understand the hydrocarbon prospectivity of the onshore Axios-Thermaikos basin by analyzing various geophysical (gravity, magnetic, seismic reflection) data and integrating the geophysical model with other available data. Our approach started with a qualitative analysis of the gravity and magnetic data to extract the structural and lithological trends controlling the basin formation and development. Magnetic data were further used to map the interface between the sedimentary pile and the basement. Seismic data were interpreted using different attributes and mapped in detail the geologic contacts and the tectonic regime of the basin. The density variations in depth were investigated using two-dimensional forward modeling constrained by seismic data. As a result, the 2D gravity model displays the interfaces between the formations and the main seismic-scale faults. Based on the seismic and stratigraphic data from wells, preliminary three-dimensional models were built showing the stratigraphic and tectonic regimes, including the presence of structural hydrocarbon traps, and the different depositional environments that have acted in the basin through time. The mapped tectonic structures in the onshore Axios-Thermaikos basin might also be useful for other activities of economic importance, such as gas storage and CO₂ sequestration.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"72 6","pages":"4225 - 4246"},"PeriodicalIF":2.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140967405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of broadcast RTK for automated static correction in 3D sub-bottom profiling","authors":"Jungkyun Shin,&nbsp;Jiho Ha,&nbsp;Kyoungmin Lim","doi":"10.1007/s11600-024-01371-x","DOIUrl":"10.1007/s11600-024-01371-x","url":null,"abstract":"<div><p>Various types of 3D sub-bottom profilers (SBPs) have been developed to widen the swath coverage of conventional single-channel SBPs. Nevertheless, the data acquisition process is frequently influenced by fluctuations in water depth, attributed to swells and tidal variations. These fluctuations, particularly pronounced during 3D sub-bottom profiling when source frequency bands reach several kHz, significantly distort the two-way travel time of seismic reflections, potentially hindering the generation of high-fidelity seismic cubes. In this study, high-precision 3D coordinates of each source and receiver channel were recorded in real-time during data acquisition and employed for pre-stack Kirchhoff depth migration to produce a static corrected seismic cube. To streamline the acquisition of positioning data for the survey system operating in coastal areas, broadcast real-time kinematics (RTK) was integrated to receive RTK correction signals via broadcast radio waves, facilitating a real-time method for generating 3D coordinates for each source and receiver channel. Additionally, a Kirchhoff migration algorithm was devised to efficiently generate the static corrected seismic cube using the 3D coordinates of the source and receiver. Field data were collected in waters near Jindo, South Korea, where tidal differences reached 4 m, resulting in the production of an ultrahigh-frequency seismic cube with a 50 cm bin size. The robustness and applicability of the automated static correction method were validated through analysis of the seismic cube.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"72 6","pages":"4247 - 4262"},"PeriodicalIF":2.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140968806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}