Results 161 to 170 of about 48,699 (196)
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Error in shear‐wave polarization and time splitting
Geophysical Prospecting, 2004ABSTRACTShear‐wave polarization and time delay are attributes commonly used for fracture detection and characterization. In time‐lapse analysis these parameters can be used as indicators of changes in the fracture orientation and density. Indeed, changes in fracture characteristics provide key information for increased reservoir characterization and ...
Gwénola Michaud, Roel Snieder
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Splitting parameter yield (SPY): A program for semiautomatic analysis of shear-wave splitting
Computers & Geosciences, 2012SPY is a Matlab algorithm that analyzes seismic waveforms in a semiautomatic way, providing estimates of the two observables of the anisotropy: the shear-wave splitting parameters. We chose to exploit those computational processes that require less intervention by the user, gaining objectivity and reliability as a result.
Lucia Zaccarelli +2 more
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Multichannel analysis of shear wave splitting
Journal of Geophysical Research: Solid Earth, 2000A multichannel analysis is introduced to constrain seismic anisotropy from the shear wave splitting of SKS and SKKS. This technique utilizes simultaneously a set of records coming from different azimuths. The splitting intensity of SKS waves, measured by the amplitude of the transverse component, depends on the angle between the back azimuth of the ...
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Shear-wave splitting observations on Milos, Greece
Geothermics, 1989Abstract Seismograms from local earthquakes recorded on Milos have been analysed for shear-wave splitting diagnostic of seismic anisotropy. Many complex P- and shear-wave trains were observed, indicating the presence of much heterogeneity, but shear-wave splitting was identified in most shear-wave arrivals within the shear-wave window.
D.C. Booth +4 more
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Making Reliable Shear-Wave Splitting Measurements
Bulletin of the Seismological Society of America, 2013Shear-wave splitting (SWS) analysis using SKS, SKKS, and PKS (here- after collectively called XKS) phases is one of the most commonly used techniques in structural seismology. In spite of the apparent simplicity in performing SWS measure- ments, large discrepancies in published SWS parameters (fast direction and splitting time) suggest that a ...
K. H. Liu, S. S. Gao
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Implications of temporal changes in shear‐wave splitting
SEG Technical Program Expanded Abstracts 1988, 1988Details of the behaviour of shear-wave splitting have been observed to change before and after earthquakes and before and after hydraulic fracturing. The observations before earthquakes can be interpreted as the increasing aspect ratio (dilatation) of stress-aligned EDA-cracks, and the return to thin cracks after the earthquake has released the stress.
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A physical model study of shear wave splitting and fracture intensity
SEG Technical Program Expanded Abstracts 1987, 1987Abstract In a series of physical model experiments, fractured media are simulated by stacks of thin Plexiglas sheets clamped together tightly to form blocks. The plates are assembled underwater, and a very thin water layer between the sheets prevents formation of an effectively welded interface between them. Thus, the stacked material
Robert H. Tatham +4 more
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On shear-wave splitting in the Los Angeles basin
pure and applied geophysics, 1990Three-component seismograms at the three USC stations, PVP, GFP and DHB, have been examined. Most earthquakes, with magnitudes ranging from 1.4 to 5.0, within a period from 1985 to 1988, show evidence of shear-wave splitting. The preferred polarization of the first split-shear wave arrivals at PVP is nearly in N-S which is consistent with both regional
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Shear wave splitting and subcontinental mantle deformation
Journal of Geophysical Research: Solid Earth, 1991We have made measurements of shear wave splitting in the phases SKS and SKKS at 21 broadband stations in North America, South America, Europe, Asia, and Africa. Measurements are made using a retrieval scheme that yields the azimuth of the fast polarization direction ϕ and delay time δt of the split shear wave plus uncertainties.
Paul G. Silver, W. Winston Chan
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Shear-wave splitting in the Rajasthan craton, India
Journal of Asian Earth Sciences, 2019Abstract The shear-wave splitting parameters (i.e. fast axes orientation (ψ) and delay time (δt)) are measured at four broadband stations in Rajasthan, using SKS/SKKS core phases from three-component broadband waveforms of 30 events recorded during 2014–16.
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