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Geochemistry & Geophysics
Mohsen Kazemnia Kakhki, Ahmadreza Mokhtari, Webe Joao Mansur, Vincenzo Del Gaudio
Summary: In this paper, a novel time-frequency polarization filter based on three-component sparse adaptive S transform (3C-SAST) is proposed, which demonstrates high efficiency and flexibility in seismic surface wave separation.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
T. M. Irnaka, R. Brossier, L. Metivier, T. Bohlen, Y. Pan
Summary: In this study, we investigate the methodological development and application of viscoelastic full waveform inversion on a multicomponent data set at the near-surface scale. Our results demonstrate the successful reconstruction of P-wave and S-wave velocities, as well as the precise location of an ancient trench buried at a depth of 1 meter underground.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Chih-Ping Lin, Ernian Pan, Quoc Kinh Tran, Tsai-Jung Wu
Summary: This paper proposes the use of the global stiffness matrix [K] and the Fourier-Bessel series methods to derive the accurate Green's function and dynamic response, which are directly related to the dispersion curve and experimental dispersion spectrum. The study reveals the importance of using the original Rayleigh equation in Rayleigh wave analysis and characterizes three types of leaky waves. Furthermore, the paper highlights the truncation effect as the major source of uncertainty in estimating dispersion curves for practical applications.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Jose Pina-Flores, Martin Cardenas-Soto, Antonio Garcia-Jerez, Francisco J. Sanchez-Sesma
Summary: The relationship between the Green's function and the average correlations of elastic displacements within a diffuse field has been established. The energy of motion in a diffuse field is proportional to the imaginary part of the Green's tensor. We examine the partition of elastic waves in layered elastic media due to dynamic surface loads and analyze the variations in power and modal structure.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Hao Rao, Yinhe Luo, Kaifeng Zhao, Yingjie Yang
Summary: The study introduces an alternative method called the two-station C-2 method, which uses a single station as a virtual source to retrieve surface wave phase velocities between asynchronous stations. Results show that this method can obtain reliable phase velocity measurements and can significantly improve ray path coverage and resolution in ambient noise tomography for areas between asynchronous seismic arrays.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Bruno Giammarinaro, Christina Tsarsitalidou, Gregor Hillers, Julien de Rosny, Leonard Seydoux, Stefan Catheline, Michel Campillo, Philippe Roux
Summary: Numerical experiments are conducted to explore subsurface imaging at subwavelength distances for dense seismic arrays in a laterally homogeneous layered medium. A time-reversal approach is used to simulate fundamental mode Rayleigh surface wavefields, and it is found that synthesized spatial autocorrelation fields support focal spot imaging. The accuracy of phase velocity and dispersion estimates obtained from focal spot properties is assessed through systematic tests involving different wave components and incidence conditions. The results indicate that dense array seismic Rayleigh wave focal spot imaging can increase depth sensitivity and support subwavelength resolution of lateral medium variations.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Can Oren, Jeffrey Shragge
Summary: The study proposes a methodology for microseismic image-domain wavefield tomography using the elastic wave equation and zero-lag and extended source images to improve the accuracy of elastic velocity models and event location precision.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
C. Alder, E. Debayle, T. Bodin, A. Paul, L. Stehly, H. Pedersen
Summary: Studying seismic anisotropy in the lithosphere has revealed significant radial anisotropy beneath the Apennines in Europe, differing from previous large-scale studies. This radial anisotropy is attributed to ductile horizontal flow in response to recent and present-day extension in the region.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Editorial Material
Geochemistry & Geophysics
Arjun Datta
Summary: The errors in the surface wave Green's tensor shown by Malkoti et al. have been acknowledged, as pointed out in the comment by Haney and Nakahara. The H/V amplitude ratio calculations were recomputed using expressions for Love and Rayleigh wave Green's tensors valid in the near-field provided by Haney and Nakahara. The differences due to the use of corrected Green's tensors only appear when the receivers are placed close to the edges of the modeling domain.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Fabrizio Magrini, Sebastian Lauro, Emanuel Kastle, Lapo Boschi
Summary: In order to enhance our understanding of the structure of the Earth's interior, seismologists utilize large amounts of data and automated tools for analysis. This study introduces SeisLib, an open-source Python package for multiscale seismic imaging. The functionalities of SeisLib, which include surface-wave tomography based on seismic ambient noise and teleseismic earthquakes, are demonstrated through theoretical explanations, algorithms, and applications to seismic data from North America. The results highlight the robustness and computational efficiency of SeisLib.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Yutong Zhang, Haiming Zhang
Summary: This paper reports on the synthesis of Rayleigh and Love waves in horizontally double-layered elastic half-space and analyzes their behaviors. The results show that the higher-order modes of Rayleigh waves behave differently from the fundamental mode, while different modes of Love waves exhibit similar patterns.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Chengyu Sun, Zhinong Wang, Dunshi Wu, Ruiqian Cai, Han Wu
Summary: This study derived dispersion curves of surface waves and guided waves using the transmission matrix method, and unified their characteristics through the relative amplitude dispersion map (RADM). Tests showed that RADM accurately reflects the dispersion energy of surface and guided waves, which is of great significance for inverting near-surface P and S wave velocities.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Wenyuan Fan
Summary: A new method using multiscale arrays to detect and locate seismic sources with both Love and Rayleigh surface waves is developed. The method estimates the surface wave propagation directions and arrival times independently using three-component records of three-station subarrays. The subarray estimates are then assembled to locate seismic sources and their origin times. It is found that using multiple, disconnected global networks improves location accuracy and that using both types of surface waves can enhance detection sensitivity and robustness.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Ryota Takagi, Kiwamu Nishida
Summary: We developed a method to determine multimode phase velocity dispersion curves based on the fitting of the synthetic cross-spectra to observed ones. The method can improve the depth resolution of subsurface imaging and has been shown to be stable and effective in ocean areas.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Can Oren, Jeffrey Shragge
Summary: Full-wavefield elastic imaging of active-source seismic data acquired by downhole receivers commonly offers higher-resolution subsurface images compared to conventional surface seismic data sets. However, building a accurate velocity model is a main difficulty for generating high-quality images. In this study, we adopt a 3-D image-domain elastic transmission tomography technique to construct plausible velocity models using active-source DAS VSP data. The results demonstrate the efficacy of the adopted elastic inversion technique in obtaining accurate subsurface images.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Michel Van Camp, Bruno Meurers, Olivier de Viron, Thomas Forbriger
JOURNAL OF GEODESY
(2016)
Article
Engineering, Geological
F. Garofalo, S. Foti, F. Hollender, P. Y. Bard, C. Cornou, B. R. Cox, M. Ohrnberger, D. Sicilia, M. Asten, G. Di Giulio, T. Forbriger, B. Guillier, K. Hayashi, A. Martin, S. Matsushima, D. Mercerat, V. Poggi, H. Yamanaka
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2016)
Article
Geochemistry & Geophysics
Lisa Groos, Martin Schaefer, Thomas Forbriger, Thomas Bohlen
Article
Geochemistry & Geophysics
Thomas Forbriger, Lisa Groos, Martin Schaefer
GEOPHYSICAL JOURNAL INTERNATIONAL
(2014)
Article
Geochemistry & Geophysics
Tobias Friedrich, Toni Zieger, Thomas Forbriger, Joachim R. R. Ritter
JOURNAL OF SEISMOLOGY
(2018)
Article
Geochemistry & Geophysics
Thomas Forbriger, Lingli Gao, Peter Malischewsky, Matthias Ohrnberger, Yudi Pan
GEOPHYSICAL JOURNAL INTERNATIONAL
(2020)
Article
Geochemistry & Geophysics
Thomas Forbriger, Walter Zurn, Rudolf Widmer-Schnidrig
Summary: By removing accelerations originating from atmospheric mass fluctuations, the sensitivity of vertical-component acceleration observations can be improved to levels below the specified model. Selecting time windows in recordings of high-quality sensors allows for lowering background signals to achieve lower detection levels.
SEISMOLOGICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
W. Zuern, T. Forbriger, R. Widmer-Schnidrig, P. Duffner, A. T. Ringler
Summary: The study analyzes the impact of regional atmospheric pressure changes on seismic records, attempting to model the ground accelerations caused by atmospheric pressure. The results show that at BFO, direct pressure has a significant impact, while the results obtained from Hilbert transform regression vary, possibly due to changes in the atmospheric pressure gradient.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Thea Lepage, Thomas Forbriger, Walter Zuern, Andreas Rietbrock
Summary: Contrary to popular belief, the vertical component seismic background level of Earth's body in the normal-mode band is lower than current low-noise models suggest. By correcting atmospherically induced disturbances, the low-noise level of the vertical component of the STS-1 at BFO is reduced below the Peterson low noise model. This is demonstrated through a moving window analysis of 10 years of data in the normal-mode band between 0.2 and 2 mHz.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Peter G. Malischewsky, Thomas Forbriger
GEOFISICA INTERNACIONAL
(2020)
Article
Geochemistry & Geophysics
Peter G. Malischewsky, Thomas Forbriger, Cinna Lomnitz
GEOFISICA INTERNACIONAL
(2017)
Article
Geochemistry & Geophysics
W. Zuern, T. Forbriger, R. Widmer-Schnidrig, P. Duffner, A. T. Ringler
Summary: The study reveals that tilting of the ground due to climate loading can be canceled out by pressure-induced accelerations in certain cases. Different types of seismic sensors respond differently to this effect, with sensors installed on piers being more affected.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Engineering, Geological
Sebastiano Foti, Fabrice Hollender, Flora Garofalo, Dario Albarello, Michael Asten, Pierre-Yves Bard, Cesare Comina, Cecile Cornou, Brady Cox, Giuseppe Di Giulio, Thomas Forbriger, Koichi Hayashi, Enrico Lunedei, Antony Martin, Diego Mercerat, Matthias Ohrnberger, Valerio Poggi, Florence Renalier, Deborah Sicilia, Valentina Socco
BULLETIN OF EARTHQUAKE ENGINEERING
(2018)