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San Fernando earthquake, February 9, 1971

Steinbrugge, Karl V.; Schader, Eugene E.; Bigglestone, Harry C.; Weers, Carl A.

San Francisco, Calif. : Pacific Fire Rating Bureau, 1971, PDF (705.326 1971 S73)

The San Fernando earthquake occurred at 6:01 a.m. on February 9, 1971, inflicting severe damage and major losses along the foothills of the San Gabriel Mountains and along a narrow east-west band of faulting on the valley floor. Overall strong motion lasted about 12 seconds. Its epicenter was in the San Gabriel Mountains about 5 miles north of the San Fernando Valley, much of which is a north-western section of the City of Los Angeles. The earthquake's moderate Richter magnitude of 6.6 released its energy as a result of movements on an approximately 45-degree dipping ("thrust") fault which caused surface ruptures within the cities of San Fernando and Los Angeles. The earthquake's energy release was therefore much closer to heavily populated regions than indicated by the epicenter. A total of 58 deaths and over 2500 hospital treated injuries were recorded among the current San Fernando Valley population of over 1,200,000. Losses to buildings and other structures are (August, 1971) estimated to exceed $511,000,000, of which $240,000,000 is in the private sector and $271,000,000 in the public sector. This report investiagtes damage and losses by structure type and reports on fire, communications, water and energy supply, and medical response to the earthquake.

Available online: (8 MB)