Southern California Earthquake Data Center

Significant Earthquakes and Faults

Chronological Earthquake Index

Santa Barbara Earthquake

Type of Faulting: thrust, with a small left-lateral component
Time: August 13, 1978 / 3:55 pm PDT
Location: 34° 24' N, 119° 41' W about 1 km (less than 1 mile) southeast of Santa Barbara
Magnitude: ML5.1
Fault Involved: unknown; focal mechanism suggests a fault plane dipping NNE at about 26 degrees (see below)
Depth: 12.7 km

 

There is some dispute over the exact magnitude of this earthquake. Surely, the amount of damage it caused seems excessive for its size; however, it should always be cautioned that the magnitude of an earthquake and the damage it causes by no means have an exact correlation, though certainly the two are related.

 

Whatever the case, the 1978 Santa Barbara earthquake was a certainly a damaging quake. Some 65 people sustained injuries (mostly minor), and roughly $15 million property damage occurred. Near Goleta, a freight train was derailed by the shock, several buildings were damaged, and there was minor damage to a bridge. One roof collapsed in Santa Barbara (though the building was of poor construction), some walls were cracked, and other minor damage was reported.

 

This quake and its aftershocks would have been more poorly located had it not been for an amazing coincidence -- four new seismographs were installed in the area near the epicenter just one day before the earthquake happened! From the data gathered, there is reason to suspect that this quake occurred on a shallow, north-dipping decollement underneath the Santa Barbara area. Its depth and focal mechanism are very similar to that of the Whittier Narrows earthquake, for which a similar model has been suggested.

 

The derailment of a freight train, caused by damage from the 1978
Santa Barbara earthquake. (Photo: Robin McGuire)

 

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