| Abstract: | We use seismograms of local earthquakes to image relative shear wave attenuation structure in the shallow crust beneath the region containing the Coso volcanic-geothermal area of E California. Seismograms of 16 small earthquakes show SV amplitudes which are greatly diminished at some azimuths and takeoff angles, indicating strong lateral variations in S wave attenuation in the area. 3-D images of the relative S wave attenuation structure are obtained from forward modeling and a back projection inversion of the amplitude data. The results indicate regions within a 20 by 30 by 10 km volume of the shallow crust (one shallower than 5 km) that severely attenuate SV waves passing through them. These anomalies lie beneath the Indian Wells Valley, 30 km S of the Coso volcanic field, and are coincident with the epicentral locations of recent earthquake swarms. No anomalous attenuation is seen beneath the Coso volcanic field above about 5 km depth. Geologic relations and the coincidence of anomalously slow P wave velocities suggest that the attenuation anomalies may be related to magmatism along the E Sierra front.-from Authors |
| Genre: | Article |
| ProdID: | 70014709 |
| Citation Author: | Sanders, C.; Ho-Liu, P.; Rinn, D.; Hiroo, Kanamori |
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| Citation End Page: | 3338 |
| Citation Issue: | B4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Geophysical Research |
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| Citation Number Of Pages: | 18 |
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| Citation Search Results Text: | Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic regionn, California ( USA).; 1988; Article; Journal; Journal of Geophysical Research; Sanders, C.; Ho-Liu, P.; Rinn, D.; Hiroo, Kanamori |
| Citation Start Page: | 3321 |
| Citation Volume: | 93 |
| Citation Year: | 1988 |
| Type: | citation/reference |
| Text: | Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic regionn, California ( USA).; 1988; Article; Journal; Journal of Geophysical Research; Sanders, C.; Ho-Liu, P.; Rinn, D.; Hiroo, Kanamori |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Fri, 1 Jan 1988 00:00 -0600 |
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