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Detailed Reference Information |
Ho-Liu, P., Kanamori, H. and Clayton, R.W. (1988). Applications of attenuation tomography to Imperial Valley and Coso-Indian Wells region, southern California. Journal of Geophysical Research 93. doi: 10.1029/88JB00554. issn: 0148-0227. |
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Spatial variations in seismic wave attenution were tomographically imaged from observed S to P wave amplitude ratios in the Imperial Valley and Coso-Indian Wells regions of southern California. In the Coso-Indian Wells region a highly attenuating body (S wave quality factor Qβ≈30) coincidence with a slow P wave anomaly mapped by Walck and Clayton (1987). This coincides suggests the presence of a 3- to 5-km depth magmatic or hydrothermal body in the Indian Wells region. In the Imperial Valley, slow P wave travel time anomalies and highly attenuating S wave anomalies were found in the Brawley seismic zone at a depth of 8--12 km. The effective S wave quality factor is very low (Qβb~20), and the P wave velocity is 10% slower than the surrounding areas. These results suggest either magmatic or hydrothermal intrusions, or fractures at depth, possibly related to active shear in the Brawley seismic zone. This attenuation tomographic technique is shown to be useful in delineating the spatial variations in seismic wave attenuation and in estimating the effective seismic quality factor of attenuation anomalies. |
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BACKGROUND DATA FILES |
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Abstract |
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Keywords
Seismology, Continental crust, Seismology, Body wave propagation, Volcanology, Hydrothermal systems, 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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