Pub Date : 2024-01-31DOI: 10.1007/s10712-023-09821-9
Bernadetta Pasierb, Grzegorz Gajek, Jan Urban, Wiesław Nawrocki
The occurrence of subsurface karst caves can cause the development of superficial depressions which, in turn, may pose a construction hazard. Identifying such a substratum requires integrated non-invasive measurement methods. The main objective of the study was to demonstrate the effectiveness of the non-invasive ERT, TLS, and GPR survey techniques in identifying the karst floor and determining the direction of discontinuities around the cave. The paper analyzes the limitations of the methods used in the study of heterogeneous media. These limitations are related to the methodology and measurement conditions, data processing, and interpretation in the context of the resolution and depth range. The study was conducted using the example of the Jaskinia pod Świecami cave, formed in the Sarmatianal calcarenites in Poland. The research confirmed its complex karst-anthropogenic genesis. The cave was formed as a result of the infiltration of rainwater and the dissolution of limestone by groundwater, while the paleokarst forms that are characteristic of it and of the surrounding caves and occur in their vicinity, i.e., narrow ridges called "karst candles", were formed as a result of water circulation during the local permafrost degradation in the middle Pleistocene. However, these forms were modified in the Upper Pleistocene and Holocene, as indicated by ERT images.
{"title":"Integrated Geophysical and Geomorphological Studies of Caves in Calcarenite Limestones (Jaskinia pod Świecami Cave, Poland)","authors":"Bernadetta Pasierb, Grzegorz Gajek, Jan Urban, Wiesław Nawrocki","doi":"10.1007/s10712-023-09821-9","DOIUrl":"10.1007/s10712-023-09821-9","url":null,"abstract":"<div><p>The occurrence of subsurface karst caves can cause the development of superficial depressions which, in turn, may pose a construction hazard. Identifying such a substratum requires integrated non-invasive measurement methods. The main objective of the study was to demonstrate the effectiveness of the non-invasive ERT, TLS, and GPR survey techniques in identifying the karst floor and determining the direction of discontinuities around the cave. The paper analyzes the limitations of the methods used in the study of heterogeneous media. These limitations are related to the methodology and measurement conditions, data processing, and interpretation in the context of the resolution and depth range. The study was conducted using the example of the Jaskinia pod Świecami cave, formed in the Sarmatianal calcarenites in Poland. The research confirmed its complex karst-anthropogenic genesis. The cave was formed as a result of the infiltration of rainwater and the dissolution of limestone by groundwater, while the paleokarst forms that are characteristic of it and of the surrounding caves and occur in their vicinity, i.e., narrow ridges called \"karst candles\", were formed as a result of water circulation during the local permafrost degradation in the middle Pleistocene. However, these forms were modified in the Upper Pleistocene and Holocene, as indicated by ERT images.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 3","pages":"663 - 694"},"PeriodicalIF":4.9,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139644171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-10DOI: 10.1007/s10712-023-09814-8
Zhinong Wang, Chengyu Sun, Dunshi Wu
Compared with surface wave corresponding to the normal mode, which is widely studied, there is less research on guided-P wave corresponding to the leaking mode. Guided-P wave carries the dispersion information that can be used to construct the subsurface velocity structures. In this paper, to simultaneously estimate P-wave velocity (({{v}}_{{P}})) and S-wave velocity (({{v}}_{{S}})) structures, an integrated inversion method of guided-P and surface wave dispersion curves is proposed. Through the calculation of Jacobian matrix, the sensitivity of dispersion curves is quantitatively analyzed. It shows that the dispersion curves of guided-P and surface waves are, respectively, sensitive to the ({{v}}_{{P}}) and ({{v}}_{{S}}). Synthetic model tests demonstrate the proposed integrated inversion method can estimate the ({{v}}_{{P}}) and ({{v}}_{{S}}) models accurately and effectively identify low-velocity interlayers. The integrated inversion method is also applied to the field seismic data acquired for oil and gas prospecting. The pseudo-2D ({{v}}_{{P}}), ({{v}}_{{S}}) and Poisson’s ratio inversion results are of significance for near-surface geological interpretation. The comparison with the result of first-arrival traveltime tomography further demonstrates the accuracy and practicality of the proposed integrated inversion method. Not only in the field of exploration seismic, the guided-P wave dispersion information can also be extracted from the earthquake seismic, engineering seismic and ambient noise. The proposed inversion method can exploit previously neglected guided-P wave to characterize the subsurface ({{v}}_{{P}}) structures, showing broad and promising application prospects. This compensates for the inherent defect that the surface wave dispersion curve is mainly sensitive to the ({{v}}_{{S}}) structure.
与被广泛研究的法向模式面波相比,对泄漏模式导波的研究较少。导P波携带的频散信息可用于构建地下速度结构。为了同时估算 P 波速度(({{v}}_{P}}))和 S 波速度(({{v}}_{S}}))结构,本文提出了导波-P 波和面波频散曲线的综合反演方法。通过计算雅各布矩阵,定量分析了频散曲线的敏感性。结果表明,导波和面波的频散曲线分别对({{v}}_{P}})和({{v}}_{S}})敏感。合成模型试验表明,所提出的综合反演方法能够准确地估计({{v}}_{P}})和({{v}}_{S}})模型,并有效地识别低速夹层。综合反演方法还被应用于油气勘探采集的野外地震数据。伪二维 ({{v}}_{P}})、({{v}}_{S}})和泊松比反演结果对近地表地质解释具有重要意义。与第一到达旅行时间层析成像结果的对比进一步证明了所提出的综合反演方法的准确性和实用性。不仅在勘探地震领域,导波频散信息还可以从地震、工程地震和环境噪声中提取。所提出的反演方法可以利用以往被忽视的导P波来表征地下({{v}}_{{P}})结构,显示出广阔而有前景的应用前景。该方法弥补了地表波频散曲线主要对({{v}}_{P}})结构敏感的固有缺陷。
{"title":"Simultaneous Estimation of P- and S-Wave Velocities by Integrated Inversion of Guided-P and Surface Wave Dispersion Curves","authors":"Zhinong Wang, Chengyu Sun, Dunshi Wu","doi":"10.1007/s10712-023-09814-8","DOIUrl":"10.1007/s10712-023-09814-8","url":null,"abstract":"<div><p>Compared with surface wave corresponding to the normal mode, which is widely studied, there is less research on guided-P wave corresponding to the leaking mode. Guided-P wave carries the dispersion information that can be used to construct the subsurface velocity structures. In this paper, to simultaneously estimate P-wave velocity (<span>({{v}}_{{P}})</span>) and S-wave velocity (<span>({{v}}_{{S}})</span>) structures, an integrated inversion method of guided-P and surface wave dispersion curves is proposed. Through the calculation of Jacobian matrix, the sensitivity of dispersion curves is quantitatively analyzed. It shows that the dispersion curves of guided-P and surface waves are, respectively, sensitive to the <span>({{v}}_{{P}})</span> and <span>({{v}}_{{S}})</span>. Synthetic model tests demonstrate the proposed integrated inversion method can estimate the <span>({{v}}_{{P}})</span> and <span>({{v}}_{{S}})</span> models accurately and effectively identify low-velocity interlayers. The integrated inversion method is also applied to the field seismic data acquired for oil and gas prospecting. The pseudo-2D <span>({{v}}_{{P}})</span>, <span>({{v}}_{{S}})</span> and Poisson’s ratio inversion results are of significance for near-surface geological interpretation. The comparison with the result of first-arrival traveltime tomography further demonstrates the accuracy and practicality of the proposed integrated inversion method. Not only in the field of exploration seismic, the guided-P wave dispersion information can also be extracted from the earthquake seismic, engineering seismic and ambient noise. The proposed inversion method can exploit previously neglected guided-P wave to characterize the subsurface <span>({{v}}_{{P}})</span> structures, showing broad and promising application prospects. This compensates for the inherent defect that the surface wave dispersion curve is mainly sensitive to the <span>({{v}}_{{S}})</span> structure.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 2","pages":"429 - 458"},"PeriodicalIF":4.9,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139407428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-06DOI: 10.1007/s10712-023-09813-9
Alexander Grayver
This review presents the progress made in the last decade in the field of large-scale electromagnetic (EM) induction with natural sources, which fluctuate at periods from seconds to years and originate in oceans, ionosphere and magnetosphere. These mechanisms produce field variations that can be used to image subsurface electrical structure of Earth and planets across scales and depths from the shallow crust to the lower mantle. In the last decade, we have seen a substantial progress made in different areas related to methods, observations and 3-D numerical modelling of EM phenomena at crustal and mantle scales. Specifically, new methods for handling complex ionospheric and magnetospheric sources were proposed, accompanied by more efficient forward and inverse modelling tools that allowed us to combine several broadband sources and constrain electrical conductivity on multiple scales simultaneously. Magnetic signals due to oceanic tides were established as a new source to probe conductivity of the sub-oceanic upper mantle. Further, the launch of ESA Swarm satellites in 2013 and their successful ongoing operation have marked a new era in the field of large-scale EM induction, unlocking a set of new opportunities, but also posing new challenges. These developments were backed by new lab measurements of electrical conductivity for mantle minerals at temperatures and pressures that are getting closer to the relevant pressure and temperature conditions in the mantle, alleviating the need for inaccurate extrapolations. The latter enabled more plausible quantitative estimates of water content, melt fractions and temperature in the mantle. In parallel, crust and mantle conductivity models along with developed modelling techniques have become an integral part of geomagnetic field and geomagnetically induced currents (GICs) modelling workflows, establishing new inter-disciplinary knowledge domains.
{"title":"Unravelling the Electrical Conductivity of Earth and Planets","authors":"Alexander Grayver","doi":"10.1007/s10712-023-09813-9","DOIUrl":"10.1007/s10712-023-09813-9","url":null,"abstract":"<div><p>This review presents the progress made in the last decade in the field of large-scale electromagnetic (EM) induction with natural sources, which fluctuate at periods from seconds to years and originate in oceans, ionosphere and magnetosphere. These mechanisms produce field variations that can be used to image subsurface electrical structure of Earth and planets across scales and depths from the shallow crust to the lower mantle. In the last decade, we have seen a substantial progress made in different areas related to methods, observations and 3-D numerical modelling of EM phenomena at crustal and mantle scales. Specifically, new methods for handling complex ionospheric and magnetospheric sources were proposed, accompanied by more efficient forward and inverse modelling tools that allowed us to combine several broadband sources and constrain electrical conductivity on multiple scales simultaneously. Magnetic signals due to oceanic tides were established as a new source to probe conductivity of the sub-oceanic upper mantle. Further, the launch of ESA Swarm satellites in 2013 and their successful ongoing operation have marked a new era in the field of large-scale EM induction, unlocking a set of new opportunities, but also posing new challenges. These developments were backed by new lab measurements of electrical conductivity for mantle minerals at temperatures and pressures that are getting closer to the relevant pressure and temperature conditions in the mantle, alleviating the need for inaccurate extrapolations. The latter enabled more plausible quantitative estimates of water content, melt fractions and temperature in the mantle. In parallel, crust and mantle conductivity models along with developed modelling techniques have become an integral part of geomagnetic field and geomagnetically induced currents (GICs) modelling workflows, establishing new inter-disciplinary knowledge domains.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 1","pages":"187 - 238"},"PeriodicalIF":4.9,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10712-023-09813-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139112122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two-dimensional dense seismic ambient noise array techniques have been widely used to image and monitor subsurface structure characterization in complex urban environments. It does not have limitations in the layout under the limitation of urban space, which is more suitable for 3D S-velocity imaging. In traditional ambient seismic noise tomography, the narrowband filtering (NBF) method has many possible dispersion branches. Aliases would appear in the dispersive image, and the dispersion curve inversion also depends on the initial model. To obtain high-accuracy 3D S-velocity imaging in urban seismology, we developed a robust workflow of data processing and S-velocity tomography for 2D dense ambient noise arrays. Firstly, differing from the NBF method, we adopt the continuous wavelet transform (CWT) as an alternative method to measure the phase velocity from the interstation noise cross-correlation function (NCF) without 2π ambiguity. Then, we proposed the sequential dispersion curve inversion (DCI) strategy, which combines the Dix linear inversion and preconditioned fast descent (PFD) method to invert the S-velocity structure without prior information. Finally, the 3D S-velocity model is generated by the 3D spatial interpolation. The proposed workflow is applied to the 2D dense ambient seismic array dataset in Changchun City. The quality evaluation methods include residual iteration error, horizontal-to-vertical spectral ratio (HVSR) map, and electrical resistivity tomography (ERT). All tests indicate that the developed workflow provides a reliable 3D S-velocity model, which offers a reference for urban subsurface space exploration.
{"title":"Three-Dimensional Urban Subsurface Space Tomography with Dense Ambient Noise Seismic Array","authors":"Ruizhe Sun, Jing Li, Yingwei Yan, Hui Liu, Lige Bai, Yuqing Chen","doi":"10.1007/s10712-023-09819-3","DOIUrl":"10.1007/s10712-023-09819-3","url":null,"abstract":"<div><p>Two-dimensional dense seismic ambient noise array techniques have been widely used to image and monitor subsurface structure characterization in complex urban environments. It does not have limitations in the layout under the limitation of urban space, which is more suitable for 3D <i>S</i>-velocity imaging. In traditional ambient seismic noise tomography, the narrowband filtering (NBF) method has many possible dispersion branches. Aliases would appear in the dispersive image, and the dispersion curve inversion also depends on the initial model. To obtain high-accuracy 3D <i>S</i>-velocity imaging in urban seismology, we developed a robust workflow of data processing and <i>S</i>-velocity tomography for 2D dense ambient noise arrays. Firstly, differing from the NBF method, we adopt the continuous wavelet transform (CWT) as an alternative method to measure the phase velocity from the interstation noise cross-correlation function (NCF) without 2<i>π</i> ambiguity. Then, we proposed the sequential dispersion curve inversion (DCI) strategy, which combines the Dix linear inversion and preconditioned fast descent (PFD) method to invert the <i>S</i>-velocity structure without prior information. Finally, the 3D <i>S</i>-velocity model is generated by the 3D spatial interpolation. The proposed workflow is applied to the 2D dense ambient seismic array dataset in Changchun City. The quality evaluation methods include residual iteration error, horizontal-to-vertical spectral ratio (HVSR) map, and electrical resistivity tomography (ERT). All tests indicate that the developed workflow provides a reliable 3D <i>S</i>-velocity model, which offers a reference for urban subsurface space exploration.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 3","pages":"819 - 843"},"PeriodicalIF":4.9,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10712-023-09819-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139112057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-02DOI: 10.1007/s10712-023-09820-w
Song Xu, Shun Li, Zhihui Zou
The estimation of elastic properties of thin-bed formations from sonic logging is challenging. Standard slowness processing of sonic logging waveforms typically yields an average slowness log profile over the span of the receiver array, obscuring thin-layer features smaller than the array aperture. In order to enhance vertical resolution of the slowness logs, the subarray processing techniques have been developed. However, for the subarrays with smaller aperture, the semblance from subarray waveforms becomes susceptible to noise, which results in a low signal-to-noise (S/N) ratio for the processing slowness logs. To overcome the above drawbacks, we propose a slowness estimation method with the enhanced resolution ranging from the conventional array aperture resolution to the inter-receiver spacing based on the reconstruction of neighboring virtual traces (RNVTs). The method utilizes super-virtual interferometry to reconstruct a large number of waveforms for slowness extraction using redundant information from overlapping receiver subarrays. We validate the feasibility and effectiveness of the proposed method using synthetic numerical experiments. By adding different levels of noise to synthetic data, we conclude that the new method has better noise robustness. Finally, we apply this method to field data, and the estimated high-resolution slowness logs show good agreement in interbedded sand-shale sequences. Both numerical tests and examples of field data show that, the slowness logs estimated by the new method can be obtained with a high resolution as well as with a high S/N ratio, providing an effective method for assessing slowness properties from a borehole.
{"title":"High-Resolution Sonic Slowness Estimation Based on the Reconstruction of Neighboring Virtual Traces","authors":"Song Xu, Shun Li, Zhihui Zou","doi":"10.1007/s10712-023-09820-w","DOIUrl":"10.1007/s10712-023-09820-w","url":null,"abstract":"<div><p>The estimation of elastic properties of thin-bed formations from sonic logging is challenging. Standard slowness processing of sonic logging waveforms typically yields an average slowness log profile over the span of the receiver array, obscuring thin-layer features smaller than the array aperture. In order to enhance vertical resolution of the slowness logs, the subarray processing techniques have been developed. However, for the subarrays with smaller aperture, the semblance from subarray waveforms becomes susceptible to noise, which results in a low signal-to-noise (S/N) ratio for the processing slowness logs. To overcome the above drawbacks, we propose a slowness estimation method with the enhanced resolution ranging from the conventional array aperture resolution to the inter-receiver spacing based on the reconstruction of neighboring virtual traces (RNVTs). The method utilizes super-virtual interferometry to reconstruct a large number of waveforms for slowness extraction using redundant information from overlapping receiver subarrays. We validate the feasibility and effectiveness of the proposed method using synthetic numerical experiments. By adding different levels of noise to synthetic data, we conclude that the new method has better noise robustness. Finally, we apply this method to field data, and the estimated high-resolution slowness logs show good agreement in interbedded sand-shale sequences. Both numerical tests and examples of field data show that, the slowness logs estimated by the new method can be obtained with a high resolution as well as with a high S/N ratio, providing an effective method for assessing slowness properties from a borehole.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 3","pages":"721 - 743"},"PeriodicalIF":4.9,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139076616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.1007/s10712-023-09812-w
K. Asfour, R. Martin, D. El Baz, L. Bodet, B. Plazolles
The near surface is characterized by using different numerical techniques, among them seismic techniques that are non-destructive. More particularly, for a better understanding of acoustic and seismic measurements in unconsolidated granular media that can constitute the near surface, many studies have been conducted in situ and also at the laboratory scale where theoretical models have been developed. In this article, we want to model such granular media that are difficult to characterize. At the laboratory scale, dry granular media can be modelled with a homogenized power-law elastic model that depends on depth. In this context, we validate numerically a similar power-law elastic model for such media by applying it to a homogenized elastic medium or to the solid frame of a poroelastic medium that consists of solid and air components. By comparing the response of both rheologies, we want to highlight what poroelastic media can bring to better reproduce the experimental data in the time and frequency domains. To achieve this objective, we revisit studies carried out on unconsolidated granular media at the laboratory scale and we compare different models with different rheologies (elastic or poroelastic), dimensions (2D or 3D), boundary conditions (perfectly matched layer/PML, or Dirichlet) and locations of the source (modelled as a vibratory stick or a point force) in order to reproduce the experimental data. We show here that a poroelastic model describes better the amplitudes of the seismograms. Furthermore, we study the sensitivity of the seismic data to the source location, which is crucial to improve the amplitude of the signals and the detection of the different seismic modes.
{"title":"Impact of Source Modelling and Poroelastic Models on Numerical Modelling of Unconsolidated Granular Media: Application at the Laboratory Scale","authors":"K. Asfour, R. Martin, D. El Baz, L. Bodet, B. Plazolles","doi":"10.1007/s10712-023-09812-w","DOIUrl":"10.1007/s10712-023-09812-w","url":null,"abstract":"<div><p>The near surface is characterized by using different numerical techniques, among them seismic techniques that are non-destructive. More particularly, for a better understanding of acoustic and seismic measurements in unconsolidated granular media that can constitute the near surface, many studies have been conducted in situ and also at the laboratory scale where theoretical models have been developed. In this article, we want to model such granular media that are difficult to characterize. At the laboratory scale, dry granular media can be modelled with a homogenized power-law elastic model that depends on depth. In this context, we validate numerically a similar power-law elastic model for such media by applying it to a homogenized elastic medium or to the solid frame of a poroelastic medium that consists of solid and air components. By comparing the response of both rheologies, we want to highlight what poroelastic media can bring to better reproduce the experimental data in the time and frequency domains. To achieve this objective, we revisit studies carried out on unconsolidated granular media at the laboratory scale and we compare different models with different rheologies (elastic or poroelastic), dimensions (2D or 3D), boundary conditions (perfectly matched layer/PML, or Dirichlet) and locations of the source (modelled as a vibratory stick or a point force) in order to reproduce the experimental data. We show here that a poroelastic model describes better the amplitudes of the seismograms. Furthermore, we study the sensitivity of the seismic data to the source location, which is crucial to improve the amplitude of the signals and the detection of the different seismic modes.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 2","pages":"489 - 524"},"PeriodicalIF":4.9,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138740590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-09DOI: 10.1007/s10712-023-09816-6
Bo Guan, Jianghai Xia, Ya Liu, Chaoqiang Xi, Binbin Mi, Hao Zhang, Jingyin Pang, Baiyang You
The retrieval of surface waves from ambient noise is important for delineating the solid earth’s near-surface structures, especially in urban environments. Seismic interferometry (SI) with linear arrays is becoming popular in urban areas with abundant anthropogenic noise. However, retrieving the noise correlation functions (NCFs) is usually challenging for a dense linear array under the demand of short-time recordings and the limited number of stations in urban environments. We comprehensively compare the SI and three-station interferometry, and the results show that the convolution-based three-station interferometry can accurately retrieve the NCFs using short-time recordings for dense linear arrays from traffic-induced noise. A synthetic example demonstrates the superiority of the convolution-based three-station interferometry over the traditional SI and the correlation-based three-station interferometry. Results from two field examples validate the convolution-based three-station interferometry for linear arrays deployed synchronously and asynchronously and confirm its advantage for multi-component data. We conclude that the convolution-based three-station interferometry performs better because it makes better use of linear arrays with short-time recordings and retrieves higher-quality NCFs.
从环境噪声中获取面波对于确定地球近地表结构非常重要,尤其是在城市环境中。采用线性阵列的地震干涉测量法(SI)在人为噪声较多的城市地区越来越受欢迎。然而,在城市环境中,由于短时间记录的要求和站点数量有限,检索噪声相关函数(NCF)对于密集线性阵列来说通常具有挑战性。我们对 SI 和三站干涉测量法进行了全面比较,结果表明基于卷积的三站干涉测量法可以利用短时记录从交通诱导噪声中准确检索密集线性阵列的 NCF。一个合成实例证明了基于卷积的三站干涉测量法优于传统的 SI 和基于相关的三站干涉测量法。两个现场示例的结果验证了基于卷积的三站干涉测量法适用于同步和异步部署的线性阵列,并证实了它在多分量数据方面的优势。我们的结论是,基于卷积的三站干涉测量法性能更好,因为它能更好地利用短时间记录的线性阵列,并检索到更高质量的 NCF。
{"title":"Improving the Retrieval of High-Frequency Surface Waves Using Convolution-Based Three-Station Interferometry for Dense Linear Arrays","authors":"Bo Guan, Jianghai Xia, Ya Liu, Chaoqiang Xi, Binbin Mi, Hao Zhang, Jingyin Pang, Baiyang You","doi":"10.1007/s10712-023-09816-6","DOIUrl":"10.1007/s10712-023-09816-6","url":null,"abstract":"<div><p>The retrieval of surface waves from ambient noise is important for delineating the solid earth’s near-surface structures, especially in urban environments. Seismic interferometry (SI) with linear arrays is becoming popular in urban areas with abundant anthropogenic noise. However, retrieving the noise correlation functions (NCFs) is usually challenging for a dense linear array under the demand of short-time recordings and the limited number of stations in urban environments. We comprehensively compare the SI and three-station interferometry, and the results show that the convolution-based three-station interferometry can accurately retrieve the NCFs using short-time recordings for dense linear arrays from traffic-induced noise. A synthetic example demonstrates the superiority of the convolution-based three-station interferometry over the traditional SI and the correlation-based three-station interferometry. Results from two field examples validate the convolution-based three-station interferometry for linear arrays deployed synchronously and asynchronously and confirm its advantage for multi-component data. We conclude that the convolution-based three-station interferometry performs better because it makes better use of linear arrays with short-time recordings and retrieves higher-quality NCFs.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 2","pages":"459 - 487"},"PeriodicalIF":4.9,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138559340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-30DOI: 10.1007/s10712-023-09817-5
Ahmet T. Başokur, Anne Neska
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Pub Date : 2023-11-22DOI: 10.1007/s10712-023-09808-6
Liangjun Yan
Globally, unconventional hydrocarbons, known for the symbiosis of their hydrocarbon source and reservoir, pose significant seismic exploration challenges due to their confined target regions, extensive burial depth, minimal acoustic impedance variation, marked heterogeneity, and strong anisotropy. Over the past decade, electromagnetic (EM) exploration has evolved markedly, improving resolution and reliability, thus becoming indispensable in unconventional hydrocarbon exploration. Focusing on China's application of the controlled source electromagnetic method (CSEM), this review examines the geological and electrical attributes of these reservoirs, notably the low resistivity, high polarization and strong electrical anisotropy of shale gas reservoirs. Despite the demonstrated positive correlation between induced polarization (IP) parameters and reservoir parameters, current methodologies emphasize the IP effect, inadvertently neglecting electrical anisotropy, which affects data precision. Moreover, single-source CSEM methodologies limit the observational components, acquisition density, and exploration area, impacting the accuracy and efficacy of data interpretation. Recently developed CSEM techniques in China, namely wide-frequency electromagnetic method (WFEM), time–frequency electromagnetic method (TFEM), long offset transient electromagnetic method (LOTEM), and wireless electromagnetic method (WEM), harness high-power pseudo-random binary sequence (PRBS) waveforms, reference observation and processing technology, hybrid inversion, and enhancing operational efficiency and adaptability despite the pressing need for multi-functional software for data acquisition. Case studies detail these methods' applications in shale gas sweet spot detection and continuous hydraulic fracturing monitoring, highlighting the immense potential of EM methods in unconventional hydrocarbon sweet spot detection and total organic content (TOC) predication. However, challenges persist in suppressing EM noise, streamlining 3D inversion processes, and improving the detection and evaluation of sweet spots.
{"title":"Advancements in Controlled Source Electromagnetic Methods for Prospecting Unconventional Hydrocarbon Resources in China","authors":"Liangjun Yan","doi":"10.1007/s10712-023-09808-6","DOIUrl":"10.1007/s10712-023-09808-6","url":null,"abstract":"<div><p>Globally, unconventional hydrocarbons, known for the symbiosis of their hydrocarbon source and reservoir, pose significant seismic exploration challenges due to their confined target regions, extensive burial depth, minimal acoustic impedance variation, marked heterogeneity, and strong anisotropy. Over the past decade, electromagnetic (EM) exploration has evolved markedly, improving resolution and reliability, thus becoming indispensable in unconventional hydrocarbon exploration. Focusing on China's application of the controlled source electromagnetic method (CSEM), this review examines the geological and electrical attributes of these reservoirs, notably the low resistivity, high polarization and strong electrical anisotropy of shale gas reservoirs. Despite the demonstrated positive correlation between induced polarization (IP) parameters and reservoir parameters, current methodologies emphasize the IP effect, inadvertently neglecting electrical anisotropy, which affects data precision. Moreover, single-source CSEM methodologies limit the observational components, acquisition density, and exploration area, impacting the accuracy and efficacy of data interpretation. Recently developed CSEM techniques in China, namely wide-frequency electromagnetic method (WFEM), time–frequency electromagnetic method (TFEM), long offset transient electromagnetic method (LOTEM), and wireless electromagnetic method (WEM), harness high-power pseudo-random binary sequence (PRBS) waveforms, reference observation and processing technology, hybrid inversion, and enhancing operational efficiency and adaptability despite the pressing need for multi-functional software for data acquisition. Case studies detail these methods' applications in shale gas sweet spot detection and continuous hydraulic fracturing monitoring, highlighting the immense potential of EM methods in unconventional hydrocarbon sweet spot detection and total organic content (TOC) predication. However, challenges persist in suppressing EM noise, streamlining 3D inversion processes, and improving the detection and evaluation of sweet spots.</p></div>","PeriodicalId":49458,"journal":{"name":"Surveys in Geophysics","volume":"45 1","pages":"239 - 276"},"PeriodicalIF":4.9,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10712-023-09808-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138293591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}