Journal of Applied Geophysics最新文献

{"title":"Higher-order total-variation regularization methods for 3D inversion of gravity data","authors":"Mohammad Rezaie","doi":"10.1016/j.jappgeo.2026.106123","DOIUrl":"10.1016/j.jappgeo.2026.106123","url":null,"abstract":"<div><div>Inverting gravity data is an important geophysical method for imaging underground structures, but it naturally suffers from non-uniqueness. To produce solutions that make geological sense, some form of regularization is necessary. This paper presents an improved methodology for 3D gravity data inversion using higher-order total variation regularization techniques. Traditional first-order TV regularization has proved effective for blocky geological structures with sharp contrasts but often fails when the subsurface features are complex. We propose second and third-order TV regularization schemes that have the strengths of classical TV but provide much greater flexibility in handling more general geological contexts. The optimization problem including these higher-order regularization terms is solved by the reweighted regularized conjugate gradient algorithm, carefully addressing the parameters selection and focusing strategies. We demonstrate the effectiveness of our approach through synthetic examples, including a dipping dyke model and a multiple blocks scenario, where the higher-order TV methods give better performance for the reconstruction of subsurface structures compared to the minimum norm and first-order TV regularization. Then, the methodology was further validated using field data from the Thunderbird V-Ti-Fe deposit, Ontario, Canada, where the inversion of airborne gravity gradiometer data successfully revealed subsurface density distributions well-matched by the known geological and drilling data. The results illustrate that the higher-order TV regularization produces a more focused and geologically plausible model, especially in resolving complex structures at different levels. Current advances in inversion methodology are offering superior performance for applications in mineral exploration and geological studies.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106123"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079026","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":"Geophysical survey of the medieval Castle in Sławków, Poland: Insights from ERT and EM","authors":"Maciej J. Mendecki ,&nbsp;Rafał Warchulski ,&nbsp;Mateusz Kicza","doi":"10.1016/j.jappgeo.2026.106118","DOIUrl":"10.1016/j.jappgeo.2026.106118","url":null,"abstract":"<div><div>This study presents Electrical Resistivity Tomography (ERT) and Electromagnetic Induction (EMI) measurements conducted in two areas: the Kraków Bishops' Castle (area A1) and the Municipal Park (area A2) in Sławków. ERT data are displayed as cross-sections, while EMI data are mapped. A reference resistivity of 350 Ωm was established for natural geological substrates. Anomalies exceeding this threshold suggest anthropogenic origins, including remnants of the Bishops' Castle. In A1, ERT profiles ERT1–ERT3 revealed high-resistivity anomalies linked to rock fragments, possible tunnels, and castle walls; shallower ones (&lt;2 m) were interpreted cautiously due to natural effects or artifacts. In A2, ERT4–ERT7 profiles indicated embankments, rock fragments, and inferred defensive structures. EMI confirmed anomalies: two subsurface features inside the castle near NE and SW walls (potential metallic objects or a well).</div><div>Extended verification analyzed ERT statistical analysis (RMS, χ², residual analysis, observed vs. interpreted scatter plots), Depth of Investigation Index (DOI), and for EMI data analysis (spatial data analysis, variograms, EMI-derived resistivity, in-phase difference maps, and EMI data cross-validation), emphasizing careful interpretation under complex geological-anthropogenic conditions. The study refines archaeological geophysics practices, optimizing techniques for varied materials and site histories.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106118"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038394","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":"Landslide susceptibility assessment in a reservoir area using integrated models based on time-series InSAR","authors":"Xiaoliang Xu ,&nbsp;Yu He ,&nbsp;Huifang Liu ,&nbsp;Quan Shi ,&nbsp;Xinlong Yao ,&nbsp;Kaiyu Tang","doi":"10.1016/j.jappgeo.2026.106115","DOIUrl":"10.1016/j.jappgeo.2026.106115","url":null,"abstract":"<div><div>Landslide disasters pose a serious threat to human life and property, and landslide susceptibility assessment (LSA) is a core technical approach for landslide risk prevention and control. Conventional LSA methods face challenges in efficiently extracting features and accurately classifying multi source data, and they often lack temporal responsiveness. This study proposes a multi model fusion LSA framework that integrates interferometric synthetic aperture radar (InSAR) data. The framework combines convolutional neural networks with tree based models, incorporates dynamic surface deformation data derived from InSAR inversion, and conducts joint modeling using 14 environmental factors covering topography, geology, hydrology, and human activities. In addition, the SHAP method is employed to provide an interpretable analysis of the model decision mechanisms. The results indicate that elevation, distance to rivers, slope, and surface deformation rate are the key driving factors for landslide occurrence. Among the six comparative models, the XGBoost–VGG fusion model achieves the best performance, with overall results significantly superior to other single and fusion models. Although incorporating the surface deformation factor slightly reduces the overall performance of the models, it substantially enhances their temporal responsiveness. The proposed timeliness oriented, model fusion based LSA approach provides scientific support for landslide risk assessment and demonstrates the practical engineering value of coupling model fusion techniques with dynamic surface deformation data in LSA applications.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106115"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038834","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":"Meta-transfer learning for efficient initialization of neural network wavefield solutions","authors":"Zhijun Cheng ,&nbsp;Xiang Wang ,&nbsp;Guojun Mao ,&nbsp;Weijian Mao ,&nbsp;Shijun Cheng","doi":"10.1016/j.jappgeo.2026.106116","DOIUrl":"10.1016/j.jappgeo.2026.106116","url":null,"abstract":"<div><div>Meta-learning-based physics-informed neural networks (Meta-PINN) show significant advantages in solving seismic wave equations across multi-velocity models, where model-agnostic meta-learning (MAML) algorithm is used to learn a shared initialization. The learned initialization helps physics-informed neural networks (PINNs) rapidly adapt to new seismic velocity models. However, the dual-loop optimization mechanism of MAML significantly increases meta-training cost. To address this issue, we introduce the idea of transfer learning into the meta-learning algorithm to reduce the computational burden during the meta-training stage. Specifically, we optimize the meta-model by performing fast gradient updates for a single velocity model on the support set, and then employing a parameter averaging strategy across multiple velocity models on the query set, and the resulting initialization is used for regular training of the new velocity model. Experimental results on diverse velocity models demonstrate that, compared to the conventional Meta-PINN, our method can provide a slightly faster convergence speed and, also, significantly reduce the meta-training time.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106116"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038835","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":"Real-time wave velocity evolution and thermal damage development in hollow-sphere granite: Insights from progressive heating experiments","authors":"Zixin Huang ,&nbsp;Qiaomu Luo ,&nbsp;Longjun Dong ,&nbsp;Longbin Yang ,&nbsp;Shenglan Li ,&nbsp;Xuewei Li","doi":"10.1016/j.jappgeo.2026.106105","DOIUrl":"10.1016/j.jappgeo.2026.106105","url":null,"abstract":"<div><div>Thermal effects influence rock stability in geothermal extraction and deep engineering. Wave velocity, as a key physical indicator, provides essential insights into these thermal-induced structural and mechanical changes. This study focused on the behavior and evolution of wave velocity in granite under high-temperature conditions, which is essential for assessing the stability of deep geothermal areas. A novel experimental setup was developed using an internal point heat source to simulate deep geothermal conditions while synchronously recording active ultrasonic pulse signals and temperature data. The analysis includes the anisotropy, temperature sensitivity, attenuation behavior, and spatiotemporal evolution of wave velocity. The results reveal that wave velocity exhibits pronounced anisotropy within the granite, intensifying with increasing temperature. Wave velocity shows a fluctuating decay pattern, with a stable-accelerated-stable trend in cycles of approximately 10 °C before 80 °C. The attenuation was most considerable at the initial heating phase and beyond 80 °C. Using a piecewise linear decay model, we identified critical transition points in the attenuation behavior, marked by a notable change in decay rate before and after the points. Tomographic imaging visualizes the spatial-temporal evolution of the wave velocity field, highlighting localized thermal damage and progressive crack development. The findings provide insights into early instability warnings in deep geological environments and offer theoretical and technical support for the safe extraction of deep mineral and geothermal resources.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106105"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038836","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":"Strain rate and confining pressure effects in micro-nano carbon fiber-reinforced grout: an SHPB impact study","authors":"Changxing Zhu,&nbsp;Duo Li,&nbsp;Dazhi Wu,&nbsp;Jiaxin Huo","doi":"10.1016/j.jappgeo.2026.106111","DOIUrl":"10.1016/j.jappgeo.2026.106111","url":null,"abstract":"<div><div>To mitigate disasters such as sand inrush and water gushing potentially induced by sand layer geology in underground engineering, carbon fiber-reinforced grouting materials demonstrate promising potential for remediation. However, in practical engineering, static and dynamic loads often act on surrounding rock in combination, and existing research on this aspect remains limited. To address this, this study employs micro-nano carbon fibers to modify ultrafine cement-based grouting material. Laboratory grouting reinforcement tests were conducted on graded sand layers. Using a Split Hopkinson Pressure Bar (SHPB) equipped with an active confining pressure device, systematic dynamic compression tests were performed under various impact velocities (corresponding to strain rates of 49 to 92 s⁻¹) and confining pressures (0 to 8 MPa). The results indicate that the peak stress of the specimens increases with the strain rate, exhibiting a significant strain rate effect. Under different impact velocities and confining pressures, the peak stress of fiber-containing specimens was significantly higher than that of plain specimens, confirming the enhancing and toughening effect of carbon fibers. When the confining pressure increased to 8 MPa, the peak stress of fiber-containing specimens was approximately 1.56 times higher than that under unconfined conditions, and the failure mode transitioned from tensile splitting to crushing failure. Microscopically, carbon fibers effectively inhibit crack propagation and enhance energy absorption capacity through “micro-reinforcement” and three-dimensional network bridging, with their primary failure modes being fiber debonding or fracture. The strain rate effect of the specimens originates from the combined action of microscopic damage evolution and inertial lateral confinement. The confining pressure enhancement mechanism primarily lies in suppressing brittle crack propagation, driving the material towards a triaxial stress state and inducing ductile hardening. This research reveals the dynamic response mechanism of carbon fiber-reinforced grouted bodies under coupled static-dynamic loading, providing a material basis and theoretical foundation for the reinforcement design in sand layer strata.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106111"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038837","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":"Patch selection-based dual attention unsupervised deep learning model for suppressing random and erratic noise in seismic data","authors":"Zixiang Zhou ,&nbsp;Guochang Liu ,&nbsp;Min Bai ,&nbsp;Zhaoyang Ma ,&nbsp;Zhiyong Wang ,&nbsp;Yannan Wang","doi":"10.1016/j.jappgeo.2026.106107","DOIUrl":"10.1016/j.jappgeo.2026.106107","url":null,"abstract":"<div><div>Seismic data denoising is a challenging task in complex noise environments, especially in unsupervised learning settings where labeled data is unavailable. Existing unsupervised learning methods, such as Deep Image Prior, effectively remove noise but still face issues related to network structure stability during training, which limits their accuracy. To further improve denoising performance, this paper proposes a patch selection-based dual attention deep learning model (PS-DADL) designed to suppress random and erratic noise in seismic data. First, we adopt a patch-based processing approach, selecting patches with high information content for training based on variance calculations, which improves the model's training efficiency. Then, we design a deep neural network that extracts features and recovers denoised signals through an encoder-decoder structure. Additionally, a dual attention module is introduced. This module adaptively aggregates dependencies within the data through spatial and channel attention mechanisms, enhancing feature representation and boosting the model's adaptability in complex noise environments. Experimental results show that PS-DADL, within the unsupervised learning framework, improves seismic data quality and demonstrates strong robustness, outperforming several baseline unsupervised learning methods.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106107"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038393","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":"Stratification effects of acoustic emission signal propagation in stratified rocks: Results from laboratory research","authors":"Youbang Lai ,&nbsp;Zhipeng Li ,&nbsp;Peng Liang ,&nbsp;Wenxue Deng ,&nbsp;Yang Liu","doi":"10.1016/j.jappgeo.2025.106085","DOIUrl":"10.1016/j.jappgeo.2025.106085","url":null,"abstract":"<div><div>To reveal the propagation characteristics of acoustic emission (AE) signals in layered rock and their implications for monitoring and interpretation, AE propagation tests were conducted in two directions: in-layer (parallel-to-bedding) and cross-layer (perpendicular-to-bedding). The effects of bedding on AE wave velocity, waveform, spectrum, and time–frequency characteristics were systematically analysed. Results revealed significant anisotropy: the cross-layer wave velocity was approximately 10.61% lower than the in-layer velocity. Propagation through bedding caused pronounced attenuation in amplitude, energy, and ringing count, accompanied by a significant increase in rise time, indicating waveform distortion and dispersion. The dominant frequency decreased from about 120 kHz to 50 kHz, showing strong high-frequency attenuation and energy transfer toward lower frequencies. Frequency-dependent attenuation was most pronounced in the 250–500 kHz range, moderate in 125–250 kHz, and weak below 125 kHz. The attenuation bandwidth for cross-layer propagation (62.5–500 kHz) was broader than that for in-layer propagation (125–500 kHz). These findings demonstrate that bedding interfaces play a critical role in controlling AE signal behaviour, providing a theoretical and experimental basis for improving AE source interpretation and dynamic hazard monitoring in layered rock masses.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106085"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980129","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":"Three-dimensional anisotropic modelling of magnetotelluric data to determine the boundary between cap rock and reservoir formation: A case study of the Sarab field, Iran","authors":"Mohammad Filbandi Kashkouli ,&nbsp;Matthew J. Comeau ,&nbsp;Milad Farshad ,&nbsp;Abolghasem Kamkar-Rouhani","doi":"10.1016/j.jappgeo.2025.106077","DOIUrl":"10.1016/j.jappgeo.2025.106077","url":null,"abstract":"<div><div>Reservoirs of interest for resource exploration, including geothermal and hydrocarbon reservoirs, commonly have an impermeable cap, which traps fluids below. Identifying this boundary is important for resource development. The cap rock for hydrocarbon reservoirs in southwest Iran contains evaporites and thus some geophysical exploration methods, specifically seismic reflection, have faced problems recovering subsurface information in this environment. As an alternative, we generate an electrical resistivity model from magnetotelluric (MT) data. Furthermore, we consider three-dimensional triaxial electrical anisotropy, which is rarely done. The study objectives are to a) define and map the boundary between the cap rock and the principal reservoir, b) characterize geological and tectonic formations in the area, and c) analyze the tectonic factors influencing the evolution of the region. A total of 359 MT measurements were acquired across the Sarab field in an array consisting of five profiles separated by &gt;2000 m with a measurement spacing of &gt;200 m. Transient electromagnetic (TEM) measurements were co-located with the MT measurements at 181 locations and used to correct for static shifts. Isotropic and anisotropic inversions of the MT data were performed, using all impedance tensor elements. The anisotropic electrical resistivity model exhibits both a significantly better alignment with the depths of geological formations known from drilling data and a better fit to the data. Therefore, the boundary between the primary cap rock and principal reservoir, the Gachsaran and Asmari formations, is defined and mapped across the survey area. In addition, major tectonic and fault-related features in the region are identified.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106077"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928697","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":"NMR study on the changes of water content characteristics and pore structure evolution during melting of coal frozen with liquid nitrogen","authors":"Lei Qin ,&nbsp;Hui Wang ,&nbsp;Haifei Lin ,&nbsp;Pengfei Liu ,&nbsp;Shiyin Lv ,&nbsp;Jiawei Li","doi":"10.1016/j.jappgeo.2026.106124","DOIUrl":"10.1016/j.jappgeo.2026.106124","url":null,"abstract":"<div><div>The content of unfrozen water in frozen coal affects the permeability of coal at low temperature, and the study of the ice-water phase change during the freezing and thawing process of the coal body is the key to study the liquid nitrogen fracturing and seepage enhancement technology. In this paper, we take Hengyi bituminous coal as the research object, and study the pore structure evolution and unfrozen water distribution changes during the thawing process based on nuclear magnetic resonance technique for high water content and low water content coal samples at different freezing times. The results show that the water space ratio growth of coal samples during thawing can be divided into three stages; liquid nitrogen freeze-thaw coal sample can significantly promote the development of large pores and large pore throats, and the difference of initial water content only has a significant effect on the development of large pores and large pore throats. Pore diameter is positively correlated with pore ice melting-point, and in the frozen coal sample, the unfrozen water at the initial melting stage mainly exists in the small water space. Freezing process of low-temperature liquid nitrogen on the coal mass has been freeze-swelling and freeze-shrinking effect, different freezing time will affect the combined effect of freeze-swelling and freeze-shrinking effect, resulting in the variability of pore throat and pore space development under different freezing time.</div></div>","PeriodicalId":54882,"journal":{"name":"Journal of Applied Geophysics","volume":"246 ","pages":"Article 106124"},"PeriodicalIF":2.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038839","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}