Dynamic rupture in a layered medium: The 1966 Parkfield earthquake

Abstract

A method for computing ground motion from a propagating stress relaxation in a vertically heterogeneous medium was developed wherein computational efficiency is enhanced by separating the source, a three-dimensional calculation, from the wave propagation, a two-dimensional calculation. As an application of this technique, displacement-time histories were computed corresponding to those determined from accelerograms recorded during the 1966 Parkfield, California earthquake. On the basis of these comparisons, an effective stress of 25 bars, an average slip of 43 cm, and a moment of 2.32 × 10²⁵ dyne-cm were determined for the Parkfield earthquake.