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Detailed Reference Information |
Savage, M.K., Silver, P.G. and Meyer, R.P. (1990). Observations of teleseismic shear-wave splitting in the basin and range from portable and permanent stations. Geophysical Research Letters 17: doi: 10.1029/89GL03140. issn: 0094-8276. |
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Observations of shear-wave splitting were obtained from temporary and permanent stations in western Nevada and southern California. Measurements of fast polarization azimuth ϕ and delay time Δt were made on both SKS and direct S phases. For stations in the northern Basin and Range the results were consistent, yielding an averge of (ϕ, Δt)=(+75¿8¿, 0.9¿0.3 s). One station in the southern Basin and Range gave (+40¿11¿, 0.4¿0.1 s) and one in the Mojave Desert gave (-54¿3¿, 1.2¿0.1 s). Δt=0.9s is consistent with a 100 km-thick mantle layer characterized by 4% anisotropy. For the northern stations, the anisotropy appears unrelated to the present-day extension or absolute plate motion. Rather, we suggest that it is 'fossil' anisotropy associated with pre-Miocene extension, whose direction is about +68¿. For the California station ϕ is nearly parallel to the strike of the San Andreas Fault system, and is attributed to shear strain associated with relative plate motion. ¿ American Geophysical Union 1990 |
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Abstract |
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Keywords
Seismology, Body wave propagation, Information Related to Geographic Region, North America |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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