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

[31]

Hudson J.A., Knopoff L., Predicting the Overall Properties of Composites Materials with Small-scale Inclusions or Cracks, Pure. Appl. Geophys., 131, pp. 551-576, (1989)

[32]

Johnson L.R., Green's Function for Lamb's Problem, Geophysical Journal International, 37, pp. 99-131, (1974)

[33]

Kaneshima S., Ando M., Crampin S., Shear-wave Splitting above Small Earthquakes in the Kinki District of Japan, Phys. Earth. Planet. Inter., 45, pp. 45-58, (1987)

[34]

Kaneshima S., Ito H., Sugihara M., Shear-wave Splitting Observed above Small Earthquakes in a Geothermal Area of Japan, Geophys. J., 94, pp. 399-411, (1988)

[35]

Kaneshima S., Ito H., Sugihara M., Shear-wave Polarization Anisotropy Observed in a Rift Zone in Japan, Tectonophysics, 157, pp. 281-300, (1989)

[36]

Kawasaki I., Suzuki Y., Sato R., Seismic Waves Due to a Shear Fault in a Semi-infinite Medium. Part 1: Point Source, J. Phys. Earth., 21, pp. 252-284, (1973)

[37]

Lapwood E.R., The Disturbance Due to a Line Source in A Semi-infinite Elastic Medium, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 242, pp. 63-100, (1949)

[38]

Leary P.C., Li Y.-G., VSP Fracture Study of Mojave Desert Hydrofracture Borehole, EOS, 67, (1986)

[39]

Li Y.-G., Leary P.C., Aki K., Seismic Ray Tracing for VSP Observations in Inhomogeneous Aligned Fractured Rock at Oroville, EOS, 67, (1986)

[40]

Mayer E.L., McEvilly T.V., Eastwood F.S., Fracture Mapping Using Shear-wave Profiling, EOS, 66, (1985)

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