Starting in March of 1978 and continuing sporadically through July, 1978, a swarm of small earthquakes--called microearthquakes-- occurred underneath the northeastern end of the Santa Barbara Channel. This swarm did not arouse much concern, however, because microearthquakes occur frequently underneath the Santa Barbara Channel. Toward the end of the microearthquake swarm, in July and early August of 1978, however, Santa Barbara residents complained of an unusually large amount of oil and tar on local beaches. Another common occurrence for the Santa Barbara area, the oil from these natural seeps was considered only a minor nuisance.

Then, on August 13, 1978, on a sunny Sunday afternoon, the earth shifted abruptly underneath the channel causing a M 5.2 earthquake. The initial rupture started on an offshore fault, south of the city of Santa Barbara, at a depth of about 9 kilometers (5.5 miles). The earthquake then ruptured northwestward, focusing its energy toward Goleta, where the most intense ground motion was between Turnpike Road and Winchester Canyon Road, an area that includes the University of California, Santa Barbara.

A strong-motion seismograph on the UCSB campus recorded an acceleration of 0.45 times that of gravity. Another seismograph, located at the top of North Hall, recorded an acceleration of 0.94 times that of gravity. One-third of the books at the UCSB library--some 400,000 volumes--were thrown to the floor. Total damage at UCSB was over $5.5 million. Elsewhere in Goleta, store goods were thrown to the ground, windows of businesses and residences were shattered, the Santa Barbara airport terminal was left leaning, dozens of mobile homes were thrown from their supports, and a landslide blocked San Marcos Pass. Ten minutes after the earthquake a freight train heading through Goleta derailed at a kink in the tracks.

Sixty-five people were treated for injuries at local hospitals. No deaths occurred, but had classes been in session at UCSB, it is almost certain that many more serious injuries would have resulted.

Images

Map--enlarged version of above inset (51 kb)

Goleta store (66 kb)