Parkfield, California, earthquake of June 27, 1966: A three-dimensional moving dislocation

Abstract

Recordings from five strong-motion accelerograph stations have been used to derive a three-dimensional dislocation model for the Parkfield Earthquake. The model consists of a buried fault which extends from a depth of 3 km to a depth of 9 km below the ground surface. It appears from the analysis, which considers various fault lengths, that the zone of significant faulting was the 20-km-long northwestern section of the fault. The rupture velocity has been found to be between 2.4 and 2.5 km/sec and the dislocation amplitudes have been found to be about 120 cm. There have been comparisons made of the model results with geodetic data on static deformations and creep measurements following the event. In contrast with several other source mechanism studies of the Parkfield event, this model yields a picture which appears to be very consistent with both the dynamic strong-motion measurements as well as the available geodetic and creep data.