Article
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
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)
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
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
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
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
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
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
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)
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
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
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
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
Vadim Monteiller, Stephen Beller, Bastien Plazolles, Sebastien Chevrot
Summary: Injection methods are efficient means to compute synthetic seismograms of short-period teleseismic body waves in 3-D regional models, using either an incident plane wave or a complete wavefield. The effects of wave front and Earth curvature are negligible for moderate size regional domains and periods larger than 2 seconds.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Trine Dahl-Jensen, Lif Lund Jacobsen, Ann-Sophie Graulund Solund, Tine B. Larsen, Peter H. Voss
Summary: The article introduces the paper seismograms from 100 years of observations in Denmark and Greenland. Five case stories are used to illustrate the quality and variation of the seismograms, as well as the historical context of the operation of the stations.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
T. Ryberg, W. H. Geissler, W. Jokat, X. Yuan, T. Fromm, S. Pandey, B. Heit
Summary: The Walvis Ridge is a prominent hotspot track related to the opening of the South Atlantic Ocean. Through seismic experiments and tomography, the study investigates the crustal structure modified by the Tristan hotspot in the landward prolongation of the ridge and in adjacent oceanic basins. The results reveal the structural features of the crust in these areas.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Heidi Soosalu, Marja Uski, Kari Komminaho, Anu Veski
Summary: This study investigates four Estonian earthquakes in detail, including determining their focal parameters and their relationship with the regional stress field. The results indicate that these earthquakes are related to the stress field and plate movement in northern Europe.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Tabea Altenbernd-Lang, Wilfried Jokat, Wolfram Geissler, Christian Haberland, Nalin De Silva
Summary: This study presents findings on the crustal structure of southern Sri Lanka and the adjacent Indian Ocean based on seismic refraction and gravity measurements. The results show that the continental crust below southern Sri Lanka is up to 38 km thick, while the adjacent oceanic crust is 4.7 to 7 km thick and covered by sediment up to 4 km thick. The study also revealed P-wave velocity variations and unusual low upper mantle seismic velocities in certain areas.
Article
Geochemistry & Geophysics
L. Wiesenberg, C. Weidle, A. El-Sharkawy, M. Timko, S. Lebedev, T. Meier
Summary: Ambient seismic noise tomography is a well-established tool for imaging seismic properties of the Earth's crust. This paper presents an automated algorithm that fits the phase of the Hankel function to the phase of the causal symmetric part of the cross-correlation function (CCF) in order to determine phase velocity curves as continuous functions of frequency. Synthetic tests verify the reliability of the proposed method in the presence of low signal-to-noise ratio. The method is particularly useful at short inter-station distances and has been applied to waveform data from seismic stations in northern Oman.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
C. Weidle, L. Wiesenberg, A. El-Sharkawy, F. Krueger, A. Scharf, P. Agard, T. Meier
Summary: This study provides detailed information about the three-dimensional underground structure in the Semail Ophiolite region in eastern Arabia, and identifies two distinct geological units in the Arabian crust. By processing and analyzing seismological data, the study reveals the crustal variations in the Late Ophiolite region and its impact on the topography.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
M. Bagagli, I Molinari, T. Diehl, E. Kissling, D. Giardini
Summary: With the use of the AlpArray Seismic Network, a consistent seismicity-catalogue for the greater Alpine region has been established, providing high-precision hypocentre locations and consistent magnitude estimation. These findings serve as a foundation for future seismic hazard studies and improvements in the region.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geography, Physical
Jens Gruetzner, Jens Matthiessen, Wolfram H. Geissler, A. Catalina Gebhardt, Michael Schreck
Summary: This study presents a new age model for investigating the late opening phase of the central Fram Strait and the early history of oceanic circulation in the Atlantic-Arctic Gateway (AAG). The revised stratigraphy suggests that ice rafting events in the Fram Strait occurred around 10.8 million years ago, later than previously estimated. The study also reveals that sediment transport in the late Tortonian period was controlled by the western branch of the West Spitsbergen Current. Furthermore, the seismic reflectors in the late Pliocene to Pleistocene correlate with episodes of ice sheet growth in the Northern Hemisphere.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geochemistry & Geophysics
Riaz Ahmed Soomro, Saleem Iqbal, Muhammad Ali Shah, Talat Iqbal
Summary: In this study, a P-wave minimum 1D velocity model for central and northern Pakistan, along with station delays, is presented. The model and delays were obtained through travel time inversions using the VELEST code. The model consists of eight layers, with the top layer having a P-wave velocity of 5.4 km/s and the bottom layer having a velocity of 8.4 km/s. The Moho boundary is located at a depth of around 50 km. The use of this model improves the accuracy of local event location and data filtering.
JOURNAL OF SEISMOLOGY
(2022)
Article
Environmental Sciences
Malgorzata Wrobel, Iwona Stan-Kleczek, Artur Marciniak, Mariusz Majdanski, Sebastian Kowalczyk, Adam Nawrot, Justyna Cader
Summary: This paper proposes a multimethod approach for imaging the landslide structure and estimating ground motion. By integrating remote sensing and multi-method geophysical imaging, the spatial variability and surface area of the landslide can be modeled more precisely, as well as the velocity field in the nearest surface.
Article
Geochemistry & Geophysics
C. Weidle, L. Wiesenberg, A. Scharf, P. Agard, A. El-Sharkawy, F. Krueger, T. Meier
Summary: The geodynamic evolution of Eastern Arabia consists of three main events: Pan-African plate assembly, Infracambrian and Ordovician extension, and Permian Pangean breakup and rifting. The obduction of the Semail Ophiolite during the Late Cretaceous and the subsequent relaxation of the lithosphere are also significant. Seismological observations reveal the lithospheric thickness and crustal heterogeneity of Eastern Arabia, indicating the segmentation of the crust and the impact of various tectonic events. The configuration of the lithosphere in northeastern Arabia preserves imprints from multiple geological periods.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Energy & Fuels
Qamar Yasin, Ali Gholami, Mariusz Majdanski, Bo Liu, Naser Golsanami
Summary: The geologic structure plays a decisive role in controlling fluid flow in geothermal systems. Seismic data can provide high-resolution images of complex structures, but it is challenging to detect the characteristics of fault edges in deep-buried and structurally complex areas. In this study, an intelligent workflow based on structure-oriented filtering and sensitive seismic attributes is proposed to characterize fault edges and fractures in geothermal reservoirs.
Article
Ecology
Artur Marciniak, Marzena Osuch, Tomasz Wawrzyniak, Bartosz Owoc, Wojciech Dobinski, Michal Glazer, Mariusz Majdanski
Summary: This article presents the results of a geophysical survey, which obtained detailed images of glacial and periglacial landforms as well as subsurface structures. The study provides valuable information for reconstructing past glaciers and understanding how they respond to climate and environmental changes. The joint interpretation of three non-intrusive geophysical methods was applied to derive spatial information from complex geomorphological terrain. The findings reveal important insights into sediment and ice thickness, as well as bedrock topography in the studied area.
POLISH POLAR RESEARCH
(2022)
Article
Environmental Sciences
Patrick A. Hoyer, Karsten M. Haase, Marcel Regelous, John M. O'Connor, Stephan Homrighausen, Wolfram H. Geissler, Wilfried Jokat
Summary: The Rio Grande Rise in the South Atlantic Ocean is an oceanic plateau formed by mantle plume and rift-related volcanism, without a continental crust component.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)