Chronological Earthquake Index
TYPE OF FAULTING: reverse
Time: July 13, 1986 / 6:47 am PDT
LOCATION: 32° 58' N, 117° 52.3' W 51 km (32 miles) WSW (offshore) from the city of Oceanside 55 km (35 miles) NW of San Diego
DEPTH: 8.8 km
FAULT INVOLVED: unidentified south-dipping fault; may be part of the San Diego Trough fault zone, Palos Verdes-Coronado Bank fault zone, or possibly some system connecting the two
At least twenty-nine injuries and one death are attributed to the 1986 Oceanside earthquake, the epicenter of which was located offshore, beneath the Pacific Ocean. At least 50 buildings were damaged, from Newport Beach to San Diego. Some damage was also reported in the Tijuana, Mexico, area. A small landslide occurred near Lakeside, in eastern San Diego county. Damage estimates reached nearly one million dollars.
This earthquake had a large aftershock sequence for its size, but because of its location offshore, the hypocenters of those aftershocks were not well located. This, combined with generally incomplete submarine geologic data have kept the causative fault something of a mystery.