Results 251 to 260 of about 48,532 (287)

Shear-wave splitting near Guam

Physics of the Earth and Planetary Interiors, 1992
Abstract 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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Shear Wave Splitting in Himalaya

Chinese Journal of Geophysics, 2007
AbstractWe 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 ...
openaire   +1 more source

Detecting false indications of shear‐wave splitting

SEG Technical Program Expanded Abstracts 2002, 2002
Summary Observations of shear-wave splitting from converted-wave seismic surveys are becoming common. When interpreting 3-C data for shear-wave splitting, it is important to be able to distinguish true indicators of shear-wave splitting from false ones.
Bruno Gratacos, Richard Bale, Pierre‐Yves Granger   +2 more
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Measuring Shear-wave Splitting Using Seismic Anisotropy

Proceedings, 2014
In this study, we investigate the feasibility of using microseismic data to invert for fracture density, fracture strike and fracture compliance ratio from shear splitting results. We simulate microseismic waveforms by propagating a moment tensor point source disturbance in a heterogeneous isotropic media using a finite difference program.
Yousef, B. M., Angus, D. A., Hildyard, M. W., Verdon, J. P., Perry, M.   +4 more
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Multichannel analysis of shear wave splitting

Journal of Geophysical Research: Solid Earth, 2000
A 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, 1989
Abstract 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, S. Schleper, S. Crampin, N. Ochmann, J. Wohlenberg   +4 more
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Shear Wave Splitting Analysis Using SKS Phase

Proceedings, 2018
Summary Anisotropy is an intrinsic part of our real Earth and the simplified assumption of an isotropic subsurface is generally not satisfied. Seismic anisotropy is mostly indicated by splitting of shear waves. We have worked on two earthquake events from the Andaman and Nicobar Islands and performed anisotropic correction for the two events by ...
T. Dev, P. Kumar
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Shear wave splitting and subcontinental mantle deformation

Journal of Geophysical Research: Solid Earth, 1991
We 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
openaire   +1 more source

A New Understanding of Shear-Wave Splitting

Proceedings, 1995
Shear-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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Error in shear‐wave polarization and time splitting

Geophysical Prospecting, 2004
ABSTRACTShear‐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
openaire   +1 more source