Journal of Applied Geophysics最新文献_第10页

Integrated geophysical assessment of engineering site and subsurface structures: A case study in Kocaeli-Yazlık region, Türkiye 工程场地与地下结构的综合地球物理评价：以Kocaeli-Yazlık地区为例，浙江大学学报（自然科学版）

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-10-28 DOI: 10.1016/j.jappgeo.2025.106008

Suhaib Qasem, Bülent Oruç, Ertan Pekşen, Mustafa Abdalrazig, Doğukan Durdağ, Elnur Gasimov

This study applied three geophysical methods to delineate the lithology, velocities, elastic moduli of the shallow subsurface layers, classify the site, and assess the geophysical parameters with depth of the engineering site in the Kocaeli-Yazlık region of Türkiye. The applied methods included 2D Seismic Refraction Tomography (SRT), 1D multichannel surface wave analysis (MASW), and electrical resistivity tomography (ERT). A nearby borehole data revealed a three-layer structure: a 15 m thick alluvial layer of clay, silt, and sand; an intermediate claystone unit (Aslanbey Formation) between 15 and 35 m; and a deeper volcanic basement (Sarısu volcanics) beyond 35 m. The 2D SRT and MASW velocity models showed a strong correlation with this stratigraphy. In the upper 15 m, low P-wave (750–975 m/s) and S-wave (160–180 m/s) velocities indicated saturated, unconsolidated alluvium, consistent with the borehole. Between 15 and 35 m, both P- and S-wave velocities increased (to 1600–2100 m/s and 250–290 m/s), reflecting the transition to compacted claystone, again aligning with the borehole log. The

{Vs}_{30}

m values of the 1D MASW ranged from 203.5 to 314.6 m/s, confirming the presence of weak, heterogeneous near-surface materials. According to NEHRP (BSSC, 2020) and TBEC (2018), the site is classified as D (medium stiff soil) and ZD (medium stiff to stiff rock), further supported by borehole correlations. The calculated elastic moduli and geotechnical parameters revealed an increasing material competence with depth, characterized by higher stiffness and bearing capacity in deeper layers, consistent with the claystone and volcanic basement observed in the borehole. The ERT results also supported this model, showing low resistivity values (1–25 Ω.m for Wenner configuration and 1–40 Ω·m for Schlumberger configuration) down to ∼30–34 m, typical of saturated alluvium and clay. These resistivity values closely align with the seismic velocities, reinforcing the presence of unconsolidated, water-rich deposits. Across all methods, the borehole data provided essential validation, confirming that the integrated geophysical approach reliably characterized the subsurface layers and their geotechnical properties.

应用3种地球物理方法对 rkiye Kocaeli-Yazlık地区浅层次表层的岩性、速度、弹性模量进行圈定，对工程场地进行分类，并对工程场地的地球物理参数进行深度评价。应用的方法包括二维地震折射层析成像（SRT）、一维多通道表面波分析（MASW）和电阻率层析成像（ERT）。附近的钻孔数据显示了一个三层结构：一个15米厚的粘土、淤泥和沙子冲积层；介于15 - 35米之间的中间粘土岩单元（Aslanbey组）；35米以上的深层火山基底（Sarısu火山）。二维SRT和MASW速度模型与该地层具有较强的相关性。在15 m上，低纵波（750 ~ 975 m/s）和横波（160 ~ 180 m/s）速度表明冲积层饱和、松散，与钻孔一致。在15 ~ 35 m之间，纵波和横波速度都增加了（分别达到1600 ~ 2100 m/s和250 ~ 290 m/s），反映了向压实粘土岩的过渡，再次与井眼测井结果一致。一维MASW的Vs30 m值在203.5 ~ 314.6 m/s之间，证实了弱非均质近地表物质的存在。根据NEHRP （BSSC, 2020）和TBEC(2018)，该场地被分类为D（中硬土）和ZD（中硬至硬岩），并进一步得到钻孔相关性的支持。计算得到的弹性模量和岩土参数显示，材料能力随深度的增加而增加，在较深的层中具有较高的刚度和承载力，与钻孔中观察到的粘土岩和火山基底相一致。ERT结果也支持该模型，显示低电阻率值（Wenner配置为1-25 Ω.m， Schlumberger配置为1-40 Ω·m）至~ 30-34 m，典型的饱和冲积层和粘土。这些电阻率值与地震速度密切相关，加强了未固结的富水矿床的存在。在所有方法中，井眼数据提供了必要的验证，证实了综合地球物理方法可靠地表征了地下地层及其岩土力学特性。

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引用次数: 0

Enhancing seismic fault segmentation for geological and engineering applications using the Boundary Deformable Convolutional Network 利用边界可变形卷积网络增强地质和工程应用中的地震断层分割

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-11-03 DOI: 10.1016/j.jappgeo.2025.106014

Xiaotian Wang , Zhijiang Zheng , La Ta , Dongzhuo Xu , Haitao Zhou , Wenlong Liu , Yanqiang Wu , Guangqi Chen

Seismic fault interpretation is essential for understanding subsurface structures and has significant applications in resource exploration and earthquake assessment. Traditional methods rely on manual delineation or handcrafted seismic attributes, which are time-consuming and prone to subjective bias. Recent deep learning models, particularly CNNs, have improved fault segmentation but struggle with long-range dependencies and boundary continuity. To address these issues, we propose BDCNet, a novel Boundary Deformable Convolutional Network, which pioneers the Boundary Deformable Convolution and Mixed Boundary Loss as its key innovations. The Boundary Deformable Convolution dynamically adjusts convolutional sampling positions using a boundary-aware directional attention mechanism, improving the ability to capture long-range dependencies and refine fault boundaries. Mixed Boundary Loss integrates Binary Cross-Entropy loss, Dice loss, and a Boundary Aware loss, enhancing the sensitivity of the model to subtle fault structures and preserving boundary continuity. We validate BDCNet on publicly available seismic datasets and conduct extensive experiments. Results demonstrate that BDCNet outperforms widely used models such as U-Net, U-Net++, and DeepLabV3+, achieving superior performance in IoU, Dice, Precision, and Recall. By effectively capturing fault structures while preserving boundary continuity, BDCNet provides a robust and automated solution for seismic fault interpretation.

地震断层解释是了解地下构造的必要条件，在资源勘探和地震评价中有着重要的应用。传统的方法依赖于人工圈定或手工制作地震属性，这既耗时又容易产生主观偏差。最近的深度学习模型，特别是cnn，已经改进了故障分割，但在长期依赖关系和边界连续性方面存在问题。为了解决这些问题，我们提出了一种新的边界可变形卷积网络BDCNet，它开创了边界可变形卷积和混合边界损失作为其关键创新。边界可变形卷积使用边界感知定向注意机制动态调整卷积采样位置，提高了捕获远程依赖关系和细化故障边界的能力。混合边界损失集成了二元交叉熵损失、骰子损失和边界感知损失，增强了模型对细微断层结构的敏感性，并保持了边界的连续性。我们在公开可用的地震数据集上验证了BDCNet，并进行了广泛的实验。结果表明，BDCNet优于U-Net、U-Net++和DeepLabV3+等广泛使用的模型，在IoU、Dice、Precision和Recall方面取得了优异的性能。通过有效捕获断层结构，同时保持边界连续性，BDCNet为地震断层解释提供了强大的自动化解决方案。

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引用次数: 0

Simulation of dielectric response in composite media based on Maxwell-Garnett theory and development of a multiphase dielectric model 基于麦克斯韦-加内特理论的复合介质介质响应模拟及多相介质模型的建立

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-11-04 DOI: 10.1016/j.jappgeo.2025.106020

Hao Hu , Shizhen Ke , Hongwei Shi , Yuhang Zhang , Hu Luo

The Maxwell-Garnett theory, a classical model for rock electrical properties, is widely used in interpreting formation dielectric characteristics and well-log responses. It enables inversion of key reservoir parameters such as water saturation and pore structure from dielectric logging data. However, its assumption of isolated inclusions may break down under conditions of high porosity or complex internal structures, leading to non-negligible prediction errors that could in turn affect the accuracy of inversion. This study employs Monte Carlo simulations to compute the effective permittivity of composite media consistent with the Maxwell-Garnett geometric assumptions and systematically analyzes the factors influencing model error and applicability. A Multiphase Iterative Maxwell-Garnett (MIMG) model is then proposed for media containing multiple types of inclusions. Results show that when inclusion permittivity exceeds that of the matrix, prediction errors increase markedly with volume fraction and permittivity contrast. In contrast, errors remain low when inclusion permittivity is lower. Regarding shape effects, errors increase with aspect ratio for oblate inclusions, while for prolate inclusions they either decrease then increase or decrease monotonically, depending on the permittivity contrast. Multiphase systems generally exhibit higher overall prediction errors than single-phase mixtures, indicating error accumulation. By iteratively introducing inclusions in a prescribed sequence, the MIMG model produces effective permittivity estimates more consistent with Maxwell-Garnett assumptions, thereby reducing prediction errors in multiphase systems and extending the theory's applicability in formation evaluation.

麦克斯韦-加内特理论是岩石电性的经典模型，被广泛用于解释地层介电特性和测井响应。它可以从介电测井数据中反演关键的储层参数，如含水饱和度和孔隙结构。然而，在高孔隙度或内部结构复杂的条件下，孤立包裹体的假设可能会被打破，导致不可忽略的预测误差，进而影响反演的准确性。本研究采用蒙特卡罗模拟方法，计算了符合Maxwell-Garnett几何假设的复合介质的有效介电常数，系统分析了影响模型误差和适用性的因素。在此基础上，提出了包含多种类型包裹体的多相迭代麦克斯韦-加内特（MIMG）模型。结果表明，当包体介电常数大于基体介电常数时，预测误差随体积分数和介电常数对比的增大而显著增大。相反，当包含介电常数较低时，误差保持较低。在形状效应方面，扁型夹杂物的误差随长宽比增大而增大，而长宽形夹杂物的误差则随介电常数对比的不同而依次减小、增大或减小。多相系统通常比单相混合物表现出更高的总体预测误差，表明误差积累。通过按规定的顺序迭代引入夹杂物，MIMG模型产生的有效介电常数估计更符合麦克斯韦-加内特假设，从而减少了多相系统的预测误差，扩大了理论在地层评价中的适用性。

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引用次数: 0

Resistivity characteristics of dense non-aqueous phase liquids contaminated clay and methods for modifying the Archie's model 致密非水相液体污染粘土的电阻率特性及修正阿奇模型的方法

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-10-28 DOI: 10.1016/j.jappgeo.2025.106009

Yinhe Guo , Dingwen Zhang , Yanmin Qi , Wenli Lin , Zimeng Zhang , Haoming Ren

The assessment of pollutant concentrations in organic contaminated sites is essential for effective remediation. This study first investigates the resistivity characteristics of contaminated clay and subsequently presents an enhanced methodology for the Archie's model, aimed at quantifying pollutant contents in the soil. Using perfluoroisobutyl methyl ether (HFE-7100) to simulate dense non-aqueous phase liquids (DNAPL), resistivity tests are conducted considering soil porosity, volumetric water content, and volumetric DNAPL content. Results demonstrate that the resistivity of contaminated clay is influenced by the synergistic effects of porosity and water content. As the volumetric water content decreases, the effect of variations in porosity on resistivity becomes increasingly pronounced. Resistivity increases linearly with volumetric pollutant content at constant water content, whereas it demonstrates a decreasing trend following a power function as water content increases at a constant pollutant content. The study introduces a pollutant impact coefficient and corrected porosity to refine the Archie resistivity model, yielding a modified version suitable for DNAPL-contaminated clay: the saturation index can be expressed as a product of functions related to volumetric water content and porosity; the pollutant impact coefficient can be derived from a quantitative analysis of the relationship between resistivity and variations in volumetric water content and volumetric pollutant content, with this study finding it to be 0.6268; the tortuosity factor exhibits a segmented linear variation with the increase in volumetric water content. These results lay a foundation for the quantitative analysis of the transport and distribution of DNAPL within clay, employing electrical resistivity imaging techniques.

有机污染场地的污染物浓度评价是有效修复的基础。本研究首先研究了受污染粘土的电阻率特征，随后提出了一种改进的方法，用于量化土壤中的污染物含量。利用全氟异丁基甲基醚（HFE-7100）模拟致密非水相液体（DNAPL），考虑土壤孔隙度、体积含水量和体积DNAPL含量进行电阻率测试。结果表明，污染粘土的电阻率受孔隙度和含水率的协同作用影响。随着体积含水量的降低，孔隙度变化对电阻率的影响越来越明显。在恒定含水量下，电阻率随体积污染物含量线性增加，而在恒定污染物含量下，电阻率随体积污染物含量增加呈幂函数递减趋势。研究引入污染物影响系数和修正孔隙度对阿奇电阻率模型进行了细化，得到了适用于dnapl污染粘土的修正版本：饱和指数可以表示为体积含水量与孔隙度相关函数的乘积；通过定量分析电阻率与体积含水量、体积污染物含量变化的关系，得出污染物影响系数为0.6268；弯曲系数随体积含水量的增加呈分段线性变化。这些结果为利用电阻率成像技术定量分析DNAPL在粘土中的运移和分布奠定了基础。

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引用次数: 0

Microgravimetric and GPR surveying for the detection of building foundations: the case of the “Basilica dello Spirito Santo” in Naples (Italy) 用微重力法和探地雷达法探测建筑物地基：以意大利那不勒斯的“圣神大教堂”为例

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-10-30 DOI: 10.1016/j.jappgeo.2025.106010

Maurizio Milano , Luigi Bianco , Mauro La Manna , Maurizio Fedi , Valentina Russo

This study shows that microgravity investigation can be a successful strategy to detect deep buried foundation in an urban context. Specifically, we focused on the challenging archaeological and engineering case of the “Basilica dello Spirito Santo” in Naples (Italy) where the foundation system was debated in last centuries due to its complex historical development. Here we show that microgravity data, processed through the Depth from Extreme Points (DEXP) transformation, inferred a quadrangular pattern consistent with the expected foundation reinforcements. Modelling indicates that the structure is located at ∼5 m depth, shallower than originally designed. Further geophysical investigations employing Ground Penetration Radar (GPR) reveal numerous shallow voids, interpreted as crypts and burial sites, although they did not yield conclusive evidence regarding the foundation structures. This would be likely due to weak permittivity contrasts with surrounding soils. Moreover, the data suggest the presence of a deeper elongated anomaly of uncertain origin, which could represent either a geological channel-like feature or an undocumented structure. The study demonstrates the effectiveness of multimethodological approaches in complex urban archaeological contexts, providing crucial information for both cultural heritage knowledge and restoration planning.

该研究表明，微重力调查可以作为一种成功的策略来探测城市环境中的深埋基础。具体来说，我们关注的是意大利那不勒斯“圣神大教堂”具有挑战性的考古和工程案例，在过去的几个世纪里，由于其复杂的历史发展，其基础系统一直备受争议。在这里，我们展示了通过极端点深度（DEXP）变换处理的微重力数据，推断出与预期基础增强一致的四边形模式。模型表明，该结构位于约5米的深度，比最初设计的浅。使用探地雷达（GPR）的进一步地球物理调查揭示了许多浅层空洞，被解释为地窖和墓地，尽管它们没有提供关于基础结构的确凿证据。这可能是由于与周围土壤的弱介电常数对比。此外，数据表明存在一个起源不确定的更深的细长异常，它可能代表一个类似地质通道的特征或一个未记录的结构。该研究证明了在复杂的城市考古背景下多方法方法的有效性，为文化遗产知识和修复规划提供了重要信息。

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引用次数: 0

Three-dimensional shear-wave velocity structure of the longnan geothermal field in the Central Jiulianshan uplift derived from seismic ambient noise tomography 基于地震环境噪声层析成像的中九连山隆南地热田三维横波速度结构

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-11-15 DOI: 10.1016/j.jappgeo.2025.106028

Ronghua Xu , Juzhi Deng , Cheng Li , Huajian Yao , Yang Gao , Zequn Wen

The Jiulianshan Uplift in Jiangxi Province, China, represents a typical mountainous convective-type geothermal metallogenic belt, where the origins of plentiful geothermal resources and the prospects for deep hot dry rock (HDR) reservoirs have attracted heightened scientific attention. This study examines the Longnan Geothermal Field in the central segment of the uplift, deploying a dense array of 195 three-component nodal seismometers to form a planar array. Utilizing seismic ambient noise tomography, a 3D shear-wave velocity structure for the upper 3 km of the crust within the study area was obtained. The imaging results were rigorously validated by integrating them with magnetotelluric and gravity inversion models, demonstrating the efficacy of ambient noise tomography in probing mountainous convective-type geothermal systems. The findings reveal widespread concealed magmatic intrusions in the top crust of the study area, spatially coupled with NE trending deep fault systems. The overlying caprocks along these faults exhibit sufficient thickness to form a characteristic HDR reservoir system defined by “basement heat source - fault conduction - caprock sealing - reservoir heat accumulation.” This discovery clarifies the deep-seated control mechanisms of the Jiulianshan geothermal system and provides novel technical methodologies and critical geological references for HDR exploration in South China.

江西九连山隆起是典型的山地对流型地热成矿带，其丰富地热资源的成因和深部热干岩储层的前景引起了科学界的高度关注。本研究对隆升中段陇南地热田进行了研究，采用195台三分量节点地震仪的密集阵列形成平面阵列。利用地震环境噪声层析成像技术，获得了研究区内地壳上部3 km的三维横波速度结构。将成像结果与大地电磁和重力反演模型相结合，对成像结果进行了严格验证，证明了环境噪声层析成像在探测山地对流型地热系统中的有效性。研究结果表明，研究区上地壳广泛隐伏岩浆侵入，在空间上与NE向深断裂系统相耦合。沿这些断层的上覆盖层具有足够的厚度，形成了“基底热源-断层传导-盖层封闭-储热聚集”的HDR储层体系。这一发现阐明了九连山地热系统的深层控制机制，为华南地区HDR勘探提供了新的技术方法和重要的地质参考。

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引用次数: 0

DG-TSEM: A discontinuous Galerkin tetrahedral spectral element method for elastic wave propagation in complex geological models 复杂地质模型中弹性波传播的不连续Galerkin四面体谱元方法

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-11-05 DOI: 10.1016/j.jappgeo.2025.106006

Naixing Feng , Shuai Zhang , Wei Wang , Zhixiang Huang

Precise modeling of elastic wave propagation in complex geological media is essential for applications including seismic exploration and geophysical simulations. Traditional numerical approaches, including the Finite Difference Method (FDM) and Finite Element Method (FEM), encounter difficulties in managing complex geometries and computational efficiency, especially for high-accuracy simulations on unstructured meshes. While hybrid hp-FEM enhances convergence properties, the costs associated with adaptive refinement and matrix inversion are still prohibitively high. Spectral Element Methods (SEM) using hexahedral meshes exhibit exponential convergence rates yet struggle to handle geometrically sharp features effectively. Tetrahedral Spectral Methods (TSEM) achieve high precision and improved geometric flexibility, yet retain the costly mass matrix inversion issue inherent to FEM. In this work, we introduce a discontinuous Galerkin tetrahedral spectral element method (DG-TSEM) to overcome these constraints. This approach integrates DG’s localized mass matrix benefits with TSEM’s high precision and geometric versatility, leverages generalized Vandermonde matrices for computationally efficient integration-free operations, and adopts Warp-Blend (WB) node arrangements to suppress Runge oscillations. Additionally, we develop a perfectly matched layer (PML) to minimize elastic wave boundary reflections and employ Message Passing Interface (MPI) parallelization to enhance computational efficiency. Numerical experiments demonstrate DG-TSEM’s superior accuracy, computational efficiency, cost-effectiveness, and the effectiveness of the PML implementation.

复杂地质介质中弹性波传播的精确建模对于地震勘探和地球物理模拟等应用至关重要。传统的数值方法，包括有限差分法（FDM）和有限元法（FEM），在处理复杂几何形状和计算效率方面遇到困难，特别是在非结构化网格上的高精度模拟。虽然混合hp-FEM增强了收敛性，但与自适应细化和矩阵反演相关的成本仍然过高。使用六面体网格的谱元方法（SEM）具有指数收敛速度，但难以有效地处理几何上的尖锐特征。四面体谱法（TSEM）具有较高的精度和几何灵活性，但保留了FEM固有的昂贵的质量矩阵反演问题。在这项工作中，我们引入了不连续伽辽金四面体谱元方法（DG-TSEM）来克服这些限制。该方法将DG的局部质量矩阵优势与tsm的高精度和几何通用性相结合，利用广义Vandermonde矩阵进行计算效率高的无积分操作，并采用Warp-Blend （WB）节点排列来抑制Runge振荡。此外，我们开发了一个完美匹配层（PML）来减少弹性波边界反射，并采用消息传递接口（MPI）并行化来提高计算效率。数值实验证明了DG-TSEM具有优越的精度、计算效率、成本效益和PML实现的有效性。

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引用次数: 0

Time-lapse self-potential signals from CO2 diffusion in solution: A laboratory perspective CO2在溶液中扩散的延时自电位信号：实验室视角

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-10-30 DOI: 10.1016/j.jappgeo.2025.106004

Warda Yousaf , Yi-an Cui , Idrees Khan , Hao Li , Jing Xie

Global warming caused primarily by anthropogenic carbon dioxide emissions, poses a severe threat to this planet. Carbon Capture and Storage (CCS) is considered a reliable solution addressing this problem. However potential CO₂ leakage requires effective monitoring. Self-potential is a cost-effective method for detecting CO₂-induced electrochemical changes at CCS sites. This study investigates SP responses to CO₂ injection in fresh water and saline environments using a hypothesis driven approach that integrates theoretical modeling, numerical simulations and laboratory experimentation. A cylindrical theoretical model predicted SP anomalies governed by ionic mobility (H⁺, HCO₃⁻), showing dipole-like signal decay (∝1/r²). Laboratory experiments validated these trends using a Plexiglas cylinder filled with saturated sand equipped with Ag-AgCl electrodes. Contrasting trends were observed in experiments 1 and 2 where, CO₂ injection into tap water led to an increase in the SP values (up to 16 mV). Chemical analysis revealed that, acidification and an increase in H⁺ ions are the reasons for this rise. This demonstrates that the microscopic process of ion mobilization drives the macroscopic geophysical response measured as the SP anomaly. Whereas, decline in SP values in saline solution is attributed to the disruption of pre-existing ionic equilibrium and the buffering capacity of NaCl, which in-turn affected “double layer” potential at the sand-solution interface. An attempt is made to highlight the sensitivity of SP measurements towards changing ionic strength, pH and ion mobility, making them effective for distinguishing CO₂ intrusion pathways in saline vs fresh water aquifers. This work enhances understanding of electrochemical changes vital for CCS reservoirs integrity and presents SP as a real-time monitoring tool for environmental risk mitigation.

全球变暖主要是由人为的二氧化碳排放引起的，对这个星球构成了严重威胁。碳捕获与封存（CCS）被认为是解决这一问题的可靠解决方案。然而，潜在的二氧化碳泄漏需要有效的监测。自电位是一种经济有效的方法，用于检测二氧化碳在CCS位点引起的电化学变化。本研究采用假设驱动的方法，将理论建模、数值模拟和实验室实验相结合，研究了淡水和盐水环境中SP对CO2注入的响应。一个圆柱形理论模型预测了由离子迁移率（H+, HCO₃−）控制的SP异常，显示出偶极子样信号衰减（∝1/r2）。实验室实验用一个装有Ag-AgCl电极的饱和砂填充的有机玻璃圆柱体验证了这些趋势。在实验1和2中观察到相反的趋势，其中，向自来水中注入二氧化碳导致SP值增加（高达16 mV）。化学分析表明，酸化和氢离子的增加是这种上升的原因。这表明微观的离子动员过程驱动了测量为SP异常的宏观地球物理响应。而盐溶液中SP值的下降是由于先前存在的离子平衡和NaCl的缓冲能力被破坏，这反过来又影响了砂-液界面的“双层”电位。试图突出SP测量对离子强度、pH值和离子迁移率变化的敏感性，使它们能够有效地区分盐水含水层和淡水含水层中的CO₂入侵途径。这项工作增强了对电化学变化的理解，这对CCS储层的完整性至关重要，并将SP作为降低环境风险的实时监测工具。

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引用次数: 0

Geophysical sub-surface characterization and development of SPT (N) value and shear wave velocity (Vs) correlation: A case study of Bahraich Tehsil, U.P., India SPT (N)值与横波速度(v)相关性的地下地球物理表征与发展——以印度Bahraich Tehsil为例

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-11-13 DOI: 10.1016/j.jappgeo.2025.106029

Neelu Patel, Md Naseem Ahamad, V.P. Singh

Seismic site characterization is crucial for evaluating how local soil conditions influence earthquake ground-motion and contribute to surface damage. The Bahraich district, situated in the Indo-Gangetic Basin near the Himalayan foothills lies in Seismic Zone IV as per the Indian seismic code, and is highly vulnerable to seismic hazards due to its stratigraphy, geology, and shallow water table. In this study seismic site characterization and correlation of corrected SPT values (N₁)₆₀ with shear wave velocity (Vs) have been developed based on 45 borehole profiles and 15 Multi Channel Analysis of Surface Wave (MASW) tests. A National Earthquake Hazard Reduction Programme (NEHRP) based seismic site classification map has been prepared from average shear wave velocity within 30 m depth (Vs₃₀) using Inverse Distance Weighting (IDW) interpolation in ArcGIS. The interpolation uncertainty remains a subject for future scope. Results show that the southern Bahraich tehsil corresponds to NEHRP class DE (loose to medium-dense sand/soft to stiff clay), while the northern part corresponds to NEHRP class D (medium dense to dense sand/stiff clay). Cross-validation with lithological logs confirmed consistency, highlighting the strength of integrating MASW and borehole data. A region-specific non-linear correlation between shear wave velocity (Vs) and SPT (N₁)₆₀ values were developed for both sandy soil (V_s = 83.23(N₁)₆₀^0.351, R² = 0.891, RMSE = 12.31 m/s) and mixed soil (V_s = 83.04(N₁)₆₀^0.350, R² = 0.889, RMSE = 12.41 m/s). The developed correlations were validated using various graphical validation techniques and compared with a range of established Indian and International empirical models. The results confirm their reliability and applicability in regional geotechnical practices.

地震场地特征对于评估当地土壤条件如何影响地震地面运动和促进地表破坏至关重要。Bahraich地区位于喜马拉雅山麓附近的印度-恒河盆地，根据印度地震规范，该地区位于第IV震区，由于其地层、地质和浅水位，极易受到地震灾害的影响。在本研究中，基于45个钻孔剖面和15个多通道表面波分析（MASW）试验，建立了地震现场表征和修正SPT值（N1）60与横波速度（Vs）的相关性。利用ArcGIS中的逆距离加权（IDW）插值，从30米深度（Vs30）内的平均横波速度绘制了一幅基于国家地震减灾计划（NEHRP）的地震站点分类图。插值的不确定性仍然是未来范围的主题。结果表明：Bahraich tehsil南部属于NEHRP DE类（松散-中密砂/软-硬粘土），北部属于NEHRP D类（中密-密砂/硬粘土）。与岩性测井交叉验证证实了一致性，突出了整合MASW和井眼数据的优势。砂质土（Vs = 83.23(N1)600.351, R2 = 0.891, RMSE = 12.31 m/s）和混合土（Vs = 83.04(N1)600.350, R2 = 0.889, RMSE = 12.41 m/s）的剪切波速（Vs）与SPT (N1)60值均存在区域间的非线性相关。利用各种图形验证技术验证了开发的相关性，并与一系列已建立的印度和国际经验模型进行了比较。结果证实了该方法在区域工程实践中的可靠性和适用性。

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引用次数: 0

Characterization of centimetre- to decimetre-scale lithological heterogeneity in reservoir models through stochastic seismic inversion and seismic facies probabilities 通过随机地震反演和地震相概率表征储层模型的厘米至分米尺度岩性非均质性

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2026-01-01 Epub Date: 2025-10-25 DOI: 10.1016/j.jappgeo.2025.105992

Seyed Ahmad Mortazavi , Achyut Mishra , Julie Dickinson , Ralf R. Haese

The lithological heterogeneities on centimetre to decimetre scale can significantly control the preferential migration of fluids such as CO₂. However, it is challenging to model such thin layers in the area between the wells due to coarse seismic data resolution. This study employs stochastic seismic inversion to enhance seismic attribute resolution by combining them with wireline log data. This allows for representing centimetre (cm)-scale lithological heterogeneity in the inter-well regions along with the uncertainty in petrophysical property distribution as multiple equiprobable scenarios are generated in contrast to deterministic inversion. High-resolution seismic porosity generated from seismic inversion was subsequently used to derive maps of likely seismic facies distributions using supervised classification. By considering the seismic facies probabilities as trends for Sequential Indicator Simulation and including wireline log data, we developed detailed facies models for Parasequence-2 of the Paaratte Formation in the Otway Basin, as part of a field experiment on geological CO₂ storage. The facies models indicate that about 60 % of the reservoir section is comprised of proximal mouth bar facies while the carbonate-cements form about 15 % of the reservoir volume. The results obtained from the application of the approach were validated against well log and power spectrum data where a strong match between predicted and acquired seismic sections was observed from threshold value of −6 dB. The methodology significantly improves representation of fine layers with a thickness of a few 10s of centimetres in geological models and can be applied to highly heterogeneous reservoirs.

厘米-分米尺度上的岩性非均质性对CO2等流体的优先运移具有重要的控制作用。然而，由于地震数据分辨率较差，对井间区域的薄层进行建模是一项挑战。本研究采用随机地震反演技术，结合电缆测井资料，提高地震属性分辨率。这种方法可以表示井间区域厘米级的岩性非均质性以及岩石物性分布的不确定性，因为与确定性反演相比，可以生成多个等概率情景。随后，利用地震反演生成的高分辨率地震孔隙度，利用监督分类导出可能的地震相分布图。通过考虑地震相概率作为顺序指示模拟的趋势，并包括电缆测井数据，我们建立了Otway盆地Paaratte组副层序-2的详细相模型，作为地质二氧化碳储存的现场实验的一部分。相模式表明，近60%的储层剖面为近口坝相，而碳酸盐岩胶结物约占储层体积的15%。应用该方法获得的结果与测井和功率谱数据进行了验证，在- 6 dB的阈值范围内，预测和获得的地震剖面之间存在很强的匹配。该方法显著改善了地质模型中厚度仅为几十厘米的细层的表示，并可应用于高度非均质储层。

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引用次数: 0