Article
Geochemistry & Geophysics
Guangsen Cheng, Chuanlin He, Zhanyuan Liang, Xingyao Yin, Xiaoyu Zhang, Yi Zheng
Summary: Although subsurface media are usually assumed to be isotropic, anisotropy is common in crustal rocks and affects the seismic response. This study presents a spherical-wave AVO inversion approach that considers the spherical-wave effect and can estimate the anisotropy parameters and wave velocities of subsurface media.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Houzhu Zhang, Hong Liang, Hongwei Liu, Yang Zhao
Summary: This study discusses the properties and decompositions of traveltime sensitivity kernels in elastic isotopic and transversely isotropic media. Analytical solutions in homogeneous isotropic elastic media are derived to better understand their properties. The kernel phase function, a key component, determines the frequency components of the sensitivity kernels, the geometrical setting of the Fresnel zones, and the resolving ability for velocity inversion. For finite-frequency traveltime inversion in transversely isotropic elastic media, sensitivity kernels are expressed using Thomsen's anisotropic parameters. Sensitivity kernels in anisotropic media can be decomposed into isotropic terms constructed by the elastic properties in the symmetry direction and correction terms due to anisotropy.
Article
Geochemistry & Geophysics
Wei Ouyang, Quan Liang, Weijian Mao, Shijun Cheng
Summary: This article presents an approach for generalized Radon transform (GRT) migration and inversion in acoustic transversely isotropic (TTI) media with a tilted symmetry axis. By perturbing the TTI medium from a background nonelliptically anisotropic medium, a concise single-scattering integral for normal move-out (NMO) pressure is obtained, which explicitly represents the perturbation scattering patterns of each parameter. The application of GRT on this scattering integral allows a direct construction of the acoustic TTI inversion operator. Numerical examples verify the effectiveness of the proposed method in the presence of steeply dipping anisotropic layering.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Geochemistry & Geophysics
Da Shuai, Alexey Stovas, Jianxin Wei, Bangrang Di, Yang Zhao
Summary: The linear slip theory is being used to characterize seismic anisotropy, particularly in transversely isotropic medium with vertical fractures. By introducing additional parameters, a monoclinic medium can be created from the orthorhombic effective medium due to the presence of vertical fractures in various azimuth angles. The research investigates the impact of fracture azimuth distribution domain and angular standard deviation on effective stiffness coefficients and anisotropy parameters, showing significant influences on elastic wave velocities and orthorhombic anisotropy parameters.
Article
Computer Science, Interdisciplinary Applications
Teddi Herring, Lindsey J. Heagy, Adam Pidlisecky, Edwin Cey
Summary: In this study, a hybrid inversion algorithm that combines parametric and smooth inversion strategies was developed to improve the estimation of subsurface conductivity. Tested on synthetic models, the hybrid inversion showed better resolution of feature boundaries and magnitudes with fewer artifacts compared to the standard smooth inversion. The sensitivity analysis demonstrated successful recovery of subsurface features under different conditions, showcasing the potential of this hybrid inversion strategy in various applications.
COMPUTERS & GEOSCIENCES
(2022)
Article
Geochemistry & Geophysics
Quan Liang, Wei Ouyang, Weijian Mao, Shijun Cheng, Xuelei Li
Summary: In this paper, a new method is proposed to address the challenging problem of high-precision inversion of acoustic wave data in complex anisotropic media. By using an appropriate parameterization and scattering integral method, the estimation of anisotropic parameters can be effectively achieved.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Geochemistry & Geophysics
Qi Hao
Summary: Modeling complex-valued traveltimes is important for developing attenuation-associated techniques in seismic data processing. We have developed a ray perturbation method to accurately calculate P-wave complex-valued travel times under a geologic condition of acoustic attenuating transversely isotropic media. This method splits the eikonal equation into two partial differential equations and solves them using the method of characteristics, resulting in a complete ray-tracing system for complex-valued traveltimes.
Article
Geochemistry & Geophysics
Mattia Aleardi, Alessandro Vinciguerra, Eusebio Stucchi, Azadeh Hojat
Summary: By utilizing a trained residual neural network as the forward operator in probabilistic inversions of electrical resistivity tomography data, this study provides a faster and more accurate approach compared to traditional methods, reducing computational workload. The method properly incorporates modelling errors and propagates them onto estimated model uncertainties, allowing for solving electrical resistivity tomography with limited hardware resources.
GEOPHYSICAL PROSPECTING
(2022)
Article
Geochemistry & Geophysics
Wei Ouyang, Quan Liang, Weijian Mao, Shijun Cheng
Summary: The compressional wave scattering phenomena in anisotropic media can be simulated using a good kinematic approximation. Retrieving anisotropic properties from seismic data free of shear waves is interesting and challenging for exploration geophysics. A method based on the true-amplitude generalized Radon transform (GRT) inversion strategy is presented for inferring material properties in acoustic transversely isotropic (TI) media with a vertical axis of symmetry (VTI).
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Geochemistry & Geophysics
Ke Chen, Lu Liu, Lele Zhang, Yang Zhao
Summary: The VTI-elastic least-squares reverse time migration method developed in this study utilizes elastic wavefield decomposition to improve the resolution, reduce migration artifacts and wave-mode crosstalk, and enhance the amplitude response of the migrated images.
Article
Geochemistry & Geophysics
Xiaoyi Wang, Yongming Lu, Jianfeng Zhang
Summary: Wave-mode separation is achieved by projecting Cartesian components of the elastic wavefield onto the polarization vectors in the orthogonal direction in order to avoid high computational costs and additional corrections. The conversion from the phase velocity direction to the polarization direction is implemented by solving the Christoffel equation, and the phase angle is calculated based on the Horn-Schunck algorithm using the similarity between seismic wave propagation and optical flow problem. The proposed approach demonstrates better robustness compared to the conventional Poynting vector, especially for complex underground structures.
GEOPHYSICAL PROSPECTING
(2021)
Article
Chemistry, Multidisciplinary
Raffaele Martorana, Patrizia Capizzi
Summary: Electrical resistivity tomography (ERT) is a widely used geophysical method for geological, hydrogeological, and geoenvironmental research. 2D ERT is more commonly used than 3D ERT due to its greater immediacy, survey speed, and simplicity in processing. However, the assumption of underground structures being two-dimensional can lead to errors when interpreting the effects of three-dimensional structures. This study aims to evaluate these effects through testing synthetic and experimental models.
APPLIED SCIENCES-BASEL
(2023)
Article
Energy & Fuels
Xi-Jun He, Jing-Shuang Li, Xue-Yuan Huang, Yan-Jie Zhou
Summary: In this study, the weighted Runge-Kutta discontinuous Galerkin (RKDG) method is extended to solve the elastic wave equations in 2D transversely isotropic media. The method shows good flexibility and applicability for dealing with undulating geometries and boundary conditions. Numerical examples demonstrate the correctness and effectiveness of the method in solving wave propagation problems in complex anisotropic medium.
Article
Geochemistry & Geophysics
Qin Li, Hanlin Wang, Xiaoying Yang, Suibo Ma, Xingye Liu, Jiang Li
Summary: The study implements a GA-based seismic prestack inversion of the TTI medium and demonstrates satisfactory performance on various models and field data. The prediction of fracture filling materials based on the theories of the equivalent medium and fracture weakness is also achieved. These findings are expected to provide theoretical guidance for the inversion of elastic parameters in anisotropic media and fracture type identification in hydrocarbon reservoirs.
JOURNAL OF GEOPHYSICS AND ENGINEERING
(2022)
Article
Biotechnology & Applied Microbiology
Ahmed S. Abu El Ata, Bassem S. Nabawy, Osman M. Badran
Summary: The study focuses on geoelectric surveys in the Ayun Mousa area to explore hidden springs, utilizing methods like self-potential measurements, vertical electrical resistivity, and electrical resistivity tomography. By analyzing anomalies and faults, the study successfully identifies known and unknown springs. This comprehensive approach provides valuable insights for further exploration and potential groundwater resource management.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Article
Geosciences, Multidisciplinary
Alper Kiyak, Can Karavul, Levent Gulen, Ertan Peksen, A. Riza Kilic
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2015)
Article
Construction & Building Technology
I. Kaplanvural, E. Peksen, K. Ozkap
CONSTRUCTION AND BUILDING MATERIALS
(2018)
Article
Geochemistry & Geophysics
Ibrahim Sertcelik, Cengiz Kurtulus, Fadime Sertcelik, Ertan Peksen, Metin Asci
JOURNAL OF GEOPHYSICS AND ENGINEERING
(2018)
Article
Archaeology
W. Rabbel, E. Erkul, H. Stuempel, T. Wunderlich, R. Pasteka, J. Papco, P. Niewoehner, S. Baris, O. Cakin, E. Peksen
ARCHAEOLOGICAL PROSPECTION
(2015)
Article
Geosciences, Multidisciplinary
Ertan Peksen, Turker Yas, A. Yekta Kayman, Coskun Ozkan
JOURNAL OF APPLIED GEOPHYSICS
(2011)
Article
Geosciences, Multidisciplinary
Kerem Ozkap, Ertan Peksen, Ismail Kaplanvural, Deniz Caka
JOURNAL OF APPLIED GEOPHYSICS
(2020)
Article
Geochemistry & Geophysics
Ertan Peksen, Turker Yas, Alper Kiyak
PURE AND APPLIED GEOPHYSICS
(2014)
