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Shear-wave splitting measurements — Problems and solutions
Tectonophysics, 2008Abstract We compare sensitivity and reliability of three basic techniques of shear-wave splitting analysis – cross-correlation of wave components, minimization of covariance matrix eigenvalues and minimizing energy on the transverse component – of both synthetic and real data, point out some problems and propose solutions.
Ludek Vecsey +2 more
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Thin layers and shear-wave splitting
Geophysics, 1991Abstract The near-surface weathering layer is considered by many to be strongly anisotropic. Any shear-wave signal passing through this low-velocity layer will inherit, to some degree, the anisotropic response of this layer. For thin weathering layers, information about previous anisotropic events may be distorted; when the thickness ...
R. D. Slack +3 more
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Null Detection in Shear-Wave Splitting Measurements
Bulletin of the Seismological Society of America, 2007Shear-wave splitting measurements are widely used to analyze orien- tations of anisotropy. We compare two different shear-wave splitting techniques, which are generally assumed to give similar results. Using a synthetic test, which covers the whole backazimuthal range, we find characteristic differences, however, in fast-axis and delay-time estimates ...
Wüstefeld, A, Bokelmann, G
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A New Understanding of Shear-Wave Splitting
Proceedings, 1995Shear-wave splitting (shear-wave- bi-refringence) diagnostic of some form of azimuthal anisotropy is widely observed in all types of rock in the uppermost 15km of the Earth's crust (Crampin and Lovell 1991).
S. Crampin, S. V. Zatsepin
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Shear Wave Splitting in Himalaya
Chinese Journal of Geophysics, 2007AbstractWe analyze the records of 56 stations in Himalaya area with the method of minimizing the eigenvalue. Splitting was observed at thirty‐nine stations of them. The average splitting time is about 0.8s. The parameters of splitting vary not only from south to north, but are also different on the two sides of the line joining the station GAIG and ...
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Bootstrapping shear-wave splitting errors
Bulletin of the Seismological Society of America, 1994Abstract We have developed a bootstrap method to estimate errors associated with inverting SKS waveforms for shear-wave splitting parameters. Although presented for shear-wave splitting inversions, this method is suitable for any waveform inversion procedure.
Eric Sandvol, Thomas Hearn
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Shear-wave splitting in compliant rocks
The Leading Edge, 2010Shear-wave splitting is a phenomenon that has received a lot of attention primarily because of its connection with vertically aligned cracks or fractures within reservoirs. However, in most cases the largest amount of shear-wave splitting is observed to occur in the near-surface layers where the rocks are the least consolidated, and so are least likely
Peter Cary +3 more
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Shear-wave splitting near Guam
Physics of the Earth and Planetary Interiors, 1992Abstract Polarities of shear waves from intermediate-focus events underneath Guam are studied. For records from a group of ten events, shear-wave splitting with faster-arriving E-W components are observed. This event group occurred within, or above, one geographic portion of the Wadati-Benioff zone, with depths ranging between 57 and 148 km.
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Amplitude effects associated with shear‐wave splitting
SEG Technical Program Expanded Abstracts 2009, 2009Shear-wave anisotropy results in a time delay between two different shear-wave polarizations S1 and S2. If there are associated differences in attenuation of the amplitudes, then simple time shifting is insufficient to match the S1 and S2 images. This ―differential‖ attenuation leads to both an additional time delay and a frequency dependent amplitude ...
Bruno Gratacos +2 more
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Evaluation of anisotropy by shear-wave splitting
Geophysics, 1985Abstract The polarizations of three-component shear wave-trains carry unique information about the internal structure of the rock through which they pass: specifically, commonly observed shear-wave splitting may contain information about the orientation of crack distributions.
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