THE SCATTERING OF SHEAR-WAVES IN THE CRUST

被引：31

作者：

CRAMPIN, S

机构：

[1] British Geological Survey, Edinburgh, EH9 3LA, Murchison House, West Mains Road

来源：

PURE AND APPLIED GEOPHYSICS | 1990年 / 132卷 / 1-2期

关键词：

EDA; extensive-dilatancy anisotropy; local SP-wave; Shear-wave splitting; stress-aligned cracks; surface interactions;

D O I：

10.1007/BF00874358

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

The two major sources of scattering for shear-waves in the crust, interactions with the topography at the surface and the effective anisotropy of aligned cracks throughout the rockmass, introduce first-order changes to the shear-wave particle-motion. At the surface, shear-waves are scattered by the topography within a wavelength or two of the recording site so that, unless the effective incidence angle is less than the critical angle sin-1VS/VP, the recorded waveforms may bear little relationship to the waveforms of the incident wave. Within the rockmass, shear-waves are scattered by extensive-dilatancy anisotropy (EDA), the distribution of stress-aligned fluid-filled cracks, microcracks, and preferentially oriented pore-space pervading most rocks in the crust. Analysis of this shear-wave splitting yields new information about the internal structure of the in situ rockmass which is not otherwise available. © 1990 Birkhäuser Verlag.

引用

页码：67 / 91

页数：25

共 48 条

[1]

Anderson D.L., Minster B., Cole D., The Effect of Oriented Cracks on Seismic Velocities, Journal of Geophysical Research, 79, pp. 4011-5015, (1974)

[2]

Atkinson B.K., Subcritical Crack Growth in Geologic Materials, Pure. Appl. Geophys., 89, pp. 4077-4114, (1984)

[3]

Booth D.C., Crampin S., Shear-wave Polarizations on a Curved Wavefront at an Isotropic Free-surface, Geophys. J. R. Astr. Soc., 82, pp. 31-45, (1985)

[4]

Booth D.C., Crampin S., Evans R., Roberts G., Shear-wave Polarizations near the North Anatolian Fault —I. Evidence for Anisotropy-induced Shear-wave Splitting, Geophys. J. R. Astr. Soc., 83, pp. 61-73, (1985)

[5]

Buchbinder G.G.T., Shear-wave Splitting and Anisotropy in the Charlevoix Seismic Zone, Quebec, Geophys. Res. Lett., 12, pp. 425-428, (1985)

[6]

Cooke P.A.V., Crampin S., Booth D.C., Shear-wave Splitting in the East African Rift Valley, EOS, 67, (1986)

[7]

Crampin S., Seismic Wave Propagation through a Cracked Solid: Polarization as a Possible Dilatancy Diagnostic, Geophysical Journal International, 53, pp. 467-496, (1978)

[8]

Crampin S., A Review of Wave Motion in Anisotropic and Cracked Elastic-media, Wave Motion, 3, pp. 343-391, (1981)

[9]

Crampin S., Evaluation of Anisotropy by Shear-wave Splitting, Geophysics, 50, pp. 142-152, (1985)

[10]

Crampin S., Evidence for Aligned Cracks in the Earth's Crust, First Break, 3, pp. 12-15, (1985)

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