Yufang Xue , Bing Luo , Yalin Chen , Jun Qin , Lanpu Chen , Yuhao Yi
{"title":"Data-driven lithofacies classification of marine shale based on deep learning approaches","authors":"Yufang Xue , Bing Luo , Yalin Chen , Jun Qin , Lanpu Chen , Yuhao Yi","doi":"10.1016/j.jappgeo.2025.105902","DOIUrl":"10.1016/j.jappgeo.2025.105902","url":null,"abstract":"<div><div>Shale lithofacies control hydrocarbon generation potential, reservoir properties, and anisotropy, thereby determining the distribution of shale “sweet spots” and guiding the selection of horizontal well target windows. Consequently, predicting shale lithofacies is crucial for the detailed evaluation, efficient exploration, and development of shale reservoirs. However, predicting lithofacies within the Wujiaping Formation of the Permian in the Hongxing area, eastern Sichuan Basin, presents significant challenges due to complex mineral compositions and strong heterogeneity. In this study, we classified the shale and its interlayers within the reservoir into five lithofacies based on total organic carbon content and mineral assemblages, with MF4 identified as the favorable lithofacies. Additionally, six logging curves (GR, AC, DEN, CNL, CAL, and LLD) were selected as input features to train and test deep learning models for automatic lithofacies prediction. To investigate the applicability of deep learning models for lithofacies identifications using well logs, six models were employed, including CNN, CNN-LSTM, CNN-BiLSTM, CNN-GRU, CNN-BiGRU, and Transformer. Notably, the Transformer model outperformed the others, achieving an <span><math><mi>Accuracy</mi></math></span> of 0.8776 and <span><math><mi>Precision</mi></math></span> of 0.9152 in shale lithofacies identification. Specifically, for the favorable lithofacies MF4, the Transformer model yielded the highest prediction performance, with <span><math><mi>F</mi><mn>1</mn><mo>−</mo><mi>score</mi></math></span> of 0.89. This study demonstrates that deep learning models can effectively identify the shale lithofacies from conventional well logs, providing valuable technical insights for developing practical approaches to identify lithofacies.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105902"},"PeriodicalIF":2.1,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Wave-equation surface waves dispersion inversion in vertical transverse isotropic media","authors":"Chengang Zhang, Jing Li, Hui Liu, Lige Bai, Ruizhe Sun, Chang Zhang","doi":"10.1016/j.jappgeo.2025.105899","DOIUrl":"10.1016/j.jappgeo.2025.105899","url":null,"abstract":"<div><div>The wave-equation dispersion inversion (WD) method is a robust approach for reconstructing the S-wave velocity structure, which does not require the assumption of layered media and is independent of source wavelets. However, theoretical analysis demonstrates that surface wave dispersion curves are sensitive to anisotropic parameters. Conventional WD is based on isotropic media, neglecting the anisotropic characteristics of the subsurface structure. To correct and evaluate the anisotropy effect, we present the theory for anisotropic Love wave-equation dispersion inversion (LWD) method based on the vertical transverse isotropic media (VTI-LWD). The synthetic and field data demonstrate that the proposed VTI-LWD significantly improves the accuracy of the S-wave velocity model while simultaneously estimating the anisotropic parameter. This provides more accurate multi-parameter information for near-surface stratigraphic structures.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105899"},"PeriodicalIF":2.1,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Seismic microzonation of Chandigarh city, northwest Himalaya, India using geophysical (active and passive techniques) along with geotechnical methods","authors":"Ambrish Kumar Mahajan, Dhaneshwari Sharma, Harsh Sharma, Priyanka","doi":"10.1016/j.jappgeo.2025.105901","DOIUrl":"10.1016/j.jappgeo.2025.105901","url":null,"abstract":"<div><div>Chandigarh city, northwest Himalaya, India is under high seismic risk due to underlain lithology and its location in the seismically active belt of Himalaya. The Ambient Noise Measurements (HVSR) from 200 sites and shear wave profiles obtained using Multiple Simulations with one Receiver (MSoR) and downhole tests were used to assess near surface material properties in Chandigarh city. The HVSR results reveal fundamental frequency variation from 0.84 to 1.09 Hz and site amplification in the order of 2 to 3.5. The joint-fit-inversion modelling of the HVSR curve with the dispersion curve helped derive geological stratum depth (160–200 m) having Vs >760 m/s. The Multi-channel Analysis of Surface Waves (MASW) provided high-resolution data to enable us to understand lateral and vertical variation up to 30 m depth and the presence of surface dissolution features underneath the city. Both active and passive geophysical methods help to develop a shear wave velocity (Vs) map of Chandigarh city and characterise the city under soil class ‘D' (180–360 m/s). The frequency map and amplification maps were also plotted using HVSR analysis. The geotechnical and geophysical data helped to generate a subsoil model of the study area and identify the main litho-types above the bedrock. The site amplification and response functions were computed for each site incorporating layer thickness, their modulus curves, shear wave velocity of each layer and soil type by simulating with strong motion earthquake. The study will help understand the pattern of damage that can be expected from future Himalayan earthquakes.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105901"},"PeriodicalIF":2.1,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144842528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Research on fractal dimension warning of microseismic spatiotemporal data for rock mass failure","authors":"Congcong Zhao , Dazhao Song , Zilong Zhou","doi":"10.1016/j.jappgeo.2025.105898","DOIUrl":"10.1016/j.jappgeo.2025.105898","url":null,"abstract":"<div><div>The research on rock mass failure and early warning mines has always constrained mine safety management and enterprise production efficiency. To interpret microseismic time and spatial data related to mining disasters, to achieve early warning of mining area disasters. Specifically, key elements of rock mass damage time and space are collected at the mining site, and events related to local potential damage are identified and extracted. They are then subjected to fractal interpretation, and an analysis method based on spatiotemporal fractal dimension is constructed. At the same time, the interpretation results are analyzed and verified by combining the distribution of on-site time and spatial elements and fractal dimension field cloud maps. Ultimately, a warning model centered on time and space was constructed, forming a method for multi-dimensional warning of mining disasters based on spatiotemporal data. When the fractal dimension value is greater than or equal to 0.52, a warning is issued; The warning accuracy can be improved from 10<sup>3</sup> m<sup>3</sup> to 1<sup>3</sup> m<sup>3</sup>. The feasibility of the method system was verified through comprehensive evaluation of fractal dimension values and combined with the actual warning range on site, providing support for mine safety production.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105898"},"PeriodicalIF":2.1,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antonio M. Casas-Sainz , Teresa Román-Berdiel , Juan J. Villalaín , Manuel Castro-Priego , Marta Pérez-Polo , Andrés Pocoví , Pilar Diarte-Blasco
{"title":"Magnetic anomalies controlled by surficial dynamics and quaternary drainage patterns in volcanic-derived soils (Tuscania, Italy)","authors":"Antonio M. Casas-Sainz , Teresa Román-Berdiel , Juan J. Villalaín , Manuel Castro-Priego , Marta Pérez-Polo , Andrés Pocoví , Pilar Diarte-Blasco","doi":"10.1016/j.jappgeo.2025.105895","DOIUrl":"10.1016/j.jappgeo.2025.105895","url":null,"abstract":"<div><div>Magnetic anomalies in an agricultural area developed over volcanic-derived soils (Tuscania, Lazio region, Italy), resulting from both weathering of tuff and lava flows and transport of detrital grains, show a linear pattern with NW-SE direction and amplitudes between 40 and 100 nT in the intensity of the total field (some of them with dipolar geometry) and up to 50 nT in the vertical magnetic gradient. The location of anomalies partly correlates with the highs and lows of the magnetic susceptibility values measured in situ and from soil samples, that range from 2000 × 10<sup>−6</sup> SI to 50000 × 10<sup>−6</sup> SI. Magnetite is the main carrier of the magnetic susceptibility, as inferred from thermomagnetic curves, whose reversibility corroborates the volcanic origin of detrital particles. The anomalies obtained, although showing a somewhat irregular orthogonal pattern, are interpreted as the result of the differential concentration of magnetic minerals related to an ancient (Quaternary) drainage system. This is corroborated by the analysis of time-series of orthophotographs, which indicate that the drainage pattern developed in the stepped Quaternary piedmont levels located above the present-day thalwegs shows a geometry consistent with the magnetic anomalies.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105895"},"PeriodicalIF":2.1,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ningbo Bai , Jiancheng Zhou , Xiangyun Hu , Bo Han , Junjun Zhou , Jian Yang , He Zhao
{"title":"Fast three-dimensional inversion of magnetotelluric data based on L-BFGS optimization","authors":"Ningbo Bai , Jiancheng Zhou , Xiangyun Hu , Bo Han , Junjun Zhou , Jian Yang , He Zhao","doi":"10.1016/j.jappgeo.2025.105894","DOIUrl":"10.1016/j.jappgeo.2025.105894","url":null,"abstract":"<div><div>Three-dimensional (3D) inversion of magnetotelluric (MT) data is crucial for accurately resolving subsurface conductivity structures and requires robust, computationally efficient inversion techniques. In this study, we propose a novel 3D MT inversion method based on the limited-memory Broyden–Fletcher–Goldfarb–Shanno (L-BFGS) optimization algorithm, implemented within an edge-based finite element framework. The L-BFGS algorithm approximates the inverse Hessian using limited memory, thereby avoiding the storage and computation of large, dense matrices. To enhance the computational efficiency of the L-BFGS inversion, we introduce two strategies targeting the most time-consuming components: forward modeling and sensitivity calculations. The first strategy employs solution space dimensionality reduction by mapping the edges of the original forward-modeling grid to a coarser grid with fewer edges but without cells merging. This approach significantly reduces the degrees of freedom needed to solve the forward problem. The second strategy transforms the reduced-dimensional linear system into an equivalent real-valued linear system, which is efficiently solved using a direct–iterative hybrid solver. Numerical experiments demonstrate that solving the reduced-dimensional real linear system with the hybrid solver substantially decreases computational time compared to solving the original complex linear system with the direct solver PARDISO. The validity and robustness of the proposed inversion algorithm were confirmed through applications to both synthetic datasets and field MT data from the Longgang Volcanic Field.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105894"},"PeriodicalIF":2.1,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abd Mujahid Hamdan , Syafrina Sari Lubis , Hamdi Rifai
{"title":"Frequency-dependent magnetic susceptibility as a proxy for monitoring ETM zones in a Volcanic River Estuary","authors":"Abd Mujahid Hamdan , Syafrina Sari Lubis , Hamdi Rifai","doi":"10.1016/j.jappgeo.2025.105896","DOIUrl":"10.1016/j.jappgeo.2025.105896","url":null,"abstract":"<div><div>Estuarine Turbidity Maximum (ETM) zones serve as critical convergence areas for suspended particles and pollutants, yet their detection in tropical volcanic estuaries remains poorly developed. This study introduces a novel application of frequency-dependent magnetic susceptibility (χ<sub>FD</sub>) of surface sediments as a high-resolution geophysical proxy for tracking ETM dynamics and microplastic (MP) convergence. Unlike prior works focusing on suspended sediments or static sampling, this research implements a spatiotemporally resolved approach by incorporating both spatial (Δχ<sub>FD</sub>) and temporal (Dχ<sub>FD</sub>) gradients. Field measurements were conducted at 11 spatial stations over five consecutive days, capturing two tidal phases per day in the Krueng Aceh River estuary, Indonesia. χ<sub>FD</sub> was analyzed alongside total suspended solids (TSS) and MP abundance, revealing a strong spatial correlation between Δχ<sub>FD</sub> and MP (<em>r</em> = 0.58), and a weaker correlation with ΔTSS (<em>r</em> = 0.27), emphasizing χ<sub>FD</sub>'s superior sensitivity in detecting microplastic retention. Magnetic characterization via hysteresis loops, supported by scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), confirmed the dominance of pseudo-single domain magnetic particles in surface sediments. These findings demonstrate the potential of χ<sub>FD</sub> gradients as non-invasive, cost-effective indicators for identifying ETM zones and pollutant hotspots, laying the groundwork for advanced, real-time magnetic sensor technologies in estuarine and coastal monitoring.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105896"},"PeriodicalIF":2.1,"publicationDate":"2025-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"HCVT-Net: A hybrid CNN-Transformer network for self-supervised 3D seismic data interpolation","authors":"Xinyang Wang , Jun Ma , Xintong Dong , Ming Cheng","doi":"10.1016/j.jappgeo.2025.105873","DOIUrl":"10.1016/j.jappgeo.2025.105873","url":null,"abstract":"<div><div>Seismic data acquisition is an essential step for seismic exploration, constituting a substantial portion of the seismic exploration budget. To reduce the data acquisition overhead, it is an effective approach to acquire sparse seismic signals and interpolate the complete seismic data using designed interpolation methods. As a trending interpolation method, convolutional neural networks (CNN)-based methods have attracted much attention and shown some success in seismic interpolation. However, due to the local perception of CNN, these methods mainly focus on extracting local features, neglecting the global features of seismic data and limiting the performance. Additionally, most of these CNN-based methods work in a supervised manner, requiring high-quality paired training data and lacking generalization capability across different seismic data, which is challenging for 3D seismic data interpolation. Aiming at these problems, we propose a hybrid CNN-Transformer network (HCVT-Net) for 3D seismic data interpolation in this paper. Specifically, we design a CNN-based Encoder–Decoder structure to enable the network to learn local features at different resolutions. Meanwhile, we propose an improved Vision Transformer and deploy it to the CNN-based structure to enhance the extraction ability of global features. Finally, we adopt a self-supervised training strategy to alleviate the dependence on the high-quality paired data. Experimental results demonstrate that our method achieves better interpolation performance than competitive methods.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105873"},"PeriodicalIF":2.1,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anatoly А. Bespalko , Junhua Luo , Denis D. Dann , Evgeny K. Pomishin
{"title":"Acoustic-electric transformations in model solid samples of cement-sand mixture in contact with aqueous salt solutions","authors":"Anatoly А. Bespalko , Junhua Luo , Denis D. Dann , Evgeny K. Pomishin","doi":"10.1016/j.jappgeo.2025.105890","DOIUrl":"10.1016/j.jappgeo.2025.105890","url":null,"abstract":"<div><div>This paper presents the results of experimental studies of the parameters of electromagnetic signals based on acoustic-electrical transformations during contact of samples of hardened cement-sand mixture with aqueous solutions of salts. The regularities of changes in the parameters of electromagnetic signals and their spectra during excitation of such contact by deterministic acoustic pulses are determined. Based on a comprehensive analysis of the obtained results, a new method for determining the degree of penetration of salt solutions into porous materials is proposed. The possibility of quantitative assessment of mineralization of natural waters by identifying changes in the parameters of electromagnetic signals during the interaction of salt solutions with porous solid samples is shown. In addition, the applicability of the considered method for monitoring the defectiveness of dielectric porous materials is shown.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"242 ","pages":"Article 105890"},"PeriodicalIF":2.1,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peng Bai , Yumei Cai , Xiaolin Xu , Weihao Li , Yongheng Zhang , Zhengyu Liu
{"title":"Three-dimensional borehole induced polarization inversion using adaptive progressive grid: Methodology and field applications","authors":"Peng Bai , Yumei Cai , Xiaolin Xu , Weihao Li , Yongheng Zhang , Zhengyu Liu","doi":"10.1016/j.jappgeo.2025.105892","DOIUrl":"10.1016/j.jappgeo.2025.105892","url":null,"abstract":"<div><div>The borehole induced polarization (BIP) method, owing to its high sensitivity to water-bearing structures, demonstrates significant advantages in detecting small-scale and complex water-related hazards ahead of tunnels. However, its performance is constrained by traditional fixed inversion grid techniques, making it difficult to meet the demands of rapid and high-resolution detection. To address these limitations, this study proposes a bidirectionally guided adaptive grid optimization strategy This method combines the benefits of two popular grid optimization techniques, namely the sensitivity matrix reconstructed from highly anomalous observational data and the change in model parameters, to thoroughly identify and refine grid regions that with high sensitivity and significant parameter changes. Building upon this foundation, an adaptive progressive inversion framework for induced polarization is developed. Building on this, this paper further proposes an adaptive progressive inversion method for induced polarization. In the initial stage of inversion, a coarse grid is employed to alleviate the ill-posedness of the inverse problem. Subsequently, during the following inversion process, the grid resolution is progressively enhanced based on the bidirectionally guided grid optimization strategy, enabling high-precision imaging of resistivity and chargeability parameters. Numerical experiments demonstrate that the proposed adaptive inversion method, while reducing the number of grid cells by 20 %, generates higher-resolution inversion grids, significantly improves the accuracy of resistivity and chargeability distributions, and increases computational efficiency by 50 %. This technique has been successfully applied in a drill-and-blast tunnel project in Northwest China, where it accurately identified water-bearing structures ahead of the tunnel face, providing crucial technical support for pre-grouting operations.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"243 ","pages":"Article 105892"},"PeriodicalIF":2.1,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}