Article
Geochemistry & Geophysics
Han Wu, Xintong Dong, Tie Zhong, Shukui Zhang, Shaoping Lu
Summary: The conventional least-squares reverse time migration (LSRTM) is a modeling-driven algorithm that aims to fit input data rather than produce high-quality imaging results. To overcome the limitations of the conventional LSRTM, a migration-driven LSRTM approach is proposed by formulating the migration process using an inverse scattering imaging condition (ISIC) to eliminate backscattering noise. Synthetic data tests and real data application demonstrate that the migration-driven LSRTM approach can solve the inversion problem more robustly and efficiently compared to the modeling-driven LSRTM.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Geochemistry & Geophysics
Yufeng Wang, Xiangyun Hu, Jerry M. Harris, Hui Zhou
Summary: The article introduces a Q-compensated viscoelastic reverse time migration technique for high-resolution crosswell imaging and proposes an explicit stabilization scheme to address numerical instability issues. By introducing a reference scaling factor, this method allows for flexible tuning of stabilization parameters.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Geochemistry & Geophysics
Yue Pan, Xiao He, Jixin Yang, Xiuming Wang
Summary: Viscoelastic reverse time migration (RTM) with attenuation compensation is applied in crosswell seismic imaging to improve imaging resolution in attenuation regions. The constant Q model is used to decouple amplitude and phase, and fractional-order amplitude and phase Laplacian operators are employed. Spectral ratio techniques reveal the relationship between attenuation and frequency in crosswell seismic imaging. The alignment and muting of direct P- and S-waves from full waves are described in detail. Synthetic examples show that the compensated RTM method images geological structures more clearly, especially tilted fractures and randomly distributed caves.
JOURNAL OF GEOPHYSICS AND ENGINEERING
(2022)
Article
Energy & Fuels
Zhen-Chun Li, Ying-Ming Qu
Summary: This article reviews the development of seismic imaging, summarizes the principles of three typical imaging methods, analyzes their imaging capabilities for special structures, and provides an outlook on the future perspectives of imaging methods.
Article
Multidisciplinary Sciences
Thorne Lay, Stuart P. Nishenko
Summary: In the western South America, six very large-magnitude earthquakes have occurred so far in this century. The history of previous earthquakes in each source region has led to the identification of seismic gaps as potential hosts for future large earthquakes. The deployment of monitoring instruments has enhanced our understanding of the faulting processes and the accumulation of slip deficit on the megathrust fault. These findings provide valuable information for assessing the current earthquake hazard along the South American subduction zone.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geochemistry & Geophysics
Hongyu Zeng, Shengji Wei, Ares Rosakis
Summary: This study investigates the impact of source-side 3D velocity structure on teleseismic travel-time in back projection analysis of large earthquakes. Travel-time data recorded by the Hi-Net array is used to reveal how travel-time errors vary with source location. The study proposes a new interpolation scheme to calibrate the travel-time error by using earthquakes located around the mainshock rupture, and validates it through relocating inland M > 5.0 earthquakes in central Japan. The calibrated back projection result is then applied to image the rupture of the 2002 Denali earthquake, revealing useful information about the rupture process.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Jingrui Luo, Xiaokai Wang, Wenchao Chen
Summary: This article investigates the possibility of applying elastic reverse time migration (RTM) to seismic data induced by high-speed trains (HST) and validates its effectiveness in acquiring subsurface structures through numerical experiments.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Geochemistry & Geophysics
Han Li, Zhiyong Suo, Chengxin Zheng, Zhenfang Li, Qingjun Zhang
Summary: This letter analyzes the influence of small time bandwidth product (TBP) on the back-projection algorithm (BPA) for synthetic aperture radar (SAR) imaging. An improved BPA is proposed to address the issues related to point spread function distortion and azimuth spectrum ambiguity caused by small TBP. The simulation and real data results demonstrate the effectiveness of the improved BPA in recovering undistorted point spread function and maintaining unambiguous spectrum.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Geochemistry & Geophysics
G. Mastella, F. Corbi, F. Funiciello, M. Rosenau
Summary: Seismotectonic analog models have been developed in the last decades to study various aspects of the seismic cycle. Foamquake, a new seismotectonic model, can mimic the first order characteristics of the seismic cycle and is a valuable tool for investigating megathrust seismicity and seismic processes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Huachen Yang, Jianzhong Zhang, Zhiqiang Wu, Zhong-Lai Huang
Summary: Reverse-time migration (RTM) is widely used for imaging subseabed layers. However, in areas with high-velocity shielding layers, the RTM images may be severely damaged. This letter proposes a new imaging condition that combines towed-streamer and ocean bottom nodes data to improve the migration images.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Davide Forcellini
Summary: The concept of seismic resilience in building design has gained attention in the past decade. The delay time, defined as the time between an earthquake event and the beginning of the repair process, is a key parameter in assessing the resilience of structures after earthquakes. This paper explores the relationship between seismic structural health monitoring (S2HM) and the assessment of seismic resilience, proposing a multidimensional definition of delay time that incorporates the accuracy of S2HM. By considering delay time, the seismic resilience of structural systems can be significantly improved.
APPLIED SCIENCES-BASEL
(2023)
Article
Environmental Sciences
Zhanye Chen, Zhiqiang Zeng, Dongning Fu, Yan Huang, Qiang Li, Xin Zhang, Jun Wan
Summary: In this paper, a topography-based back-projection algorithm (Topo-BPA) is proposed to address the issue of image reconstruction in synthetic aperture radar (SAR) with terrain variations. By introducing a beam occlusion judgment algorithm based on the assumption of spherical waves and embedding it into the classical back-projection algorithm, the proposed Topo-BPA achieves accurate reconstruction of occluded areas.
Article
Engineering, Civil
Pablo Barlek, Daniel Ambrosini, Bibiana Luccioni
Summary: Passive energy dissipation devices are widely used in structures subjected to seismic action because they do not require an external source of energy. This paper proposes a novel type of passive panel called generalized friction panel (GFP), which consists of an external metallic frame with horizontal girders and solid lead blocks that can slide in the horizontal direction within the panel's plane. Experimental and numerical studies show that GFPs with sliding blocks exhibit lower displacements than GFPs with fixed blocks.
ENGINEERING STRUCTURES
(2023)
Article
Geosciences, Multidisciplinary
Kazuya Shiraishi, Toshiki Watanabe
Summary: We applied a novel method of passive seismic reflection imaging using the RTM algorithm to actual local earthquake data collected in the Kanto region, Japan. The resulting images revealed deep crustal structures related to dual plate subduction, providing higher resolution profiles than traditional earthquake-based seismic tomography.
EARTH PLANETS AND SPACE
(2023)
Article
Geosciences, Multidisciplinary
Dapeng Zhao
Summary: Recent studies on seismic imaging of the Northwest Pacific and East Asian region have revealed significant lateral heterogeneities in the crust and upper mantle, shedding new light on various geological processes such as volcanism, earthquake mechanisms, and mantle dynamics. Significant advancements in seismic imaging techniques, particularly tomographic inversions for 3-D distribution of seismic anisotropy and attenuation, have provided important insights into lithospheric deformation, mantle convection, and the processes associated with plate subductions.
EARTH-SCIENCE REVIEWS
(2021)