| Abstract: | We compare microtremor data to weak-motion 5-wave and coda recordings at sites in San Francisco in order to clarify the range of applicability of microtremor data to ground-motion prediction. We also compare 5-wave results to coda results. For each type of data, we compute spectral ratios of motions from two soil/rock station pairs and from an uphole/downhole pair in the Marina district. We compute horizontal/vertical ratios (Nakamura‘s method) at a soil site, a rock site, and the surface and borehole instruments. In the station-pair analyses, microtremor data show amplifications at the same fundamental frequency as S waves, but the frequencies of other peaks do not agree. The amplification at frequencies higher than 2 Hz is greater in the microtremor data. Station-pair ratios of coda data generally show spectral peaks occurring at the same frequencies, but with levels varying from one to four times the amplification from S-wave ratios. Nakamura‘s method of analyzing microtremors agrees better with S-wave station-pair results than the microtremor station-pair method over a limited frequency band that varies from station to station. |
| Genre: | Article |
| ProdID: | 70019021 |
| Citation Author: | Seekins, L. C.; Wennerberg, L.; Margheriti, L.; Liu, H. -P. |
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| Citation End Page: | 635 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Bulletin of the Seismological Society of America |
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| Citation Number Of Pages: | 9 |
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| Citation Search Results Text: | Site amplification at five locations in San Francisco, California: A comparison of S waves, codas, and microtremors; 1996; Article; Journal; Bulletin of the Seismological Society of America; Seekins, L. C.; Wennerberg, L.; Margheriti, L.; Liu, H. -P. |
| Citation Start Page: | 627 |
| Citation Volume: | 86 |
| Citation Year: | 1996 |
| Type: | citation/reference |
| Text: | Site amplification at five locations in San Francisco, California: A comparison of S waves, codas, and microtremors; 1996; Article; Journal; Bulletin of the Seismological Society of America; Seekins, L. C.; Wennerberg, L.; Margheriti, L.; Liu, H. -P. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Mon, 1 Jan 1996 00:00 -0600 |
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