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Local distribution of strong earthquake ground motions

Hudson, Donald E. (1972) Local distribution of strong earthquake ground motions. Bulletin of the Seismological Society of America, 62 (6). pp. 1765-1786. ISSN 0037-1106.

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Twenty ground stations distributed over a 40-square-mile area in Pasadena recorded strong ground shaking during the San Fernando earthquake of February 9, 1971. Relative responses at 10 of these same stations as measured for small earthquakes by standard Wood-Anderson torsion seismometers are available for comparison from a study made by Gutenberg in the 1950's. Frequency spectra of strong ground motions as calculated for four sites having time-recording accelerographs assist in the interpretation of seismoscope results at the other stations. Attempts to correlate local distributions with known features of local geology such as thickness of alluvium, distance from known faults, etc., indicate that no single feature plays a dominant role in the resulting patterns. The implications of such complicated distributions for the preparation of seismic risk maps are discussed, and it is concluded that it would not be possible in the present state of knowledge to assess meaningful variations in the seismic risk throughout the Pasadena area.

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Additional Information:© 1972 Seismological Society of America. Manuscript received June 26, 1972. Thanks are expressed to Drs. A. G. Brady and A. Vijayaraghavan for assistance with data processing, and to Dr. M. D. Trifunac of the Lamont-Doherty Geological Observatory of Columbia University and the California Institute of Technology for the development of computational techniques. I am grateful to Professor R. F. Scott for preparing the calculated seismoscope response plots. Mr. Richard J. Dietman very effectively carried out the instrumental program of field installation and maintenance. The field instruments are a part of the southern California network maintained by the Seismological Field Survey of the National Oceanic and Atmospheric Administration, U.S. Department of Commerce, whose cooperation is appreciated. The project has received basic support from the National Science Foundation and from the Earthquake Research Affiliates program of the California Institute of Technology.
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Caltech Earthquake Research AffiliatesUNSPECIFIED
Issue or Number:6
Record Number:CaltechAUTHORS:20140912-135246164
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:49672
Deposited By: Tony Diaz
Deposited On:12 Sep 2014 23:42
Last Modified:03 Oct 2019 07:15

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