Near-field seismograms from a two-dimensional propagating dislocation

The exact mathematical formulation for displacements on the surface of an isotropic, homogeneous, perfectly elastic half-space due to an embedded line dislocation source is developed. This formulation is then used to model the observed strong-motion accelerometer records generated at Pacoima Dam during the San Fernando earthquake of February 9, 1971. A number of model accelerograms are generated using several dislocation time histories, fault geometries, and fault rupture propagation velocities. The dislocation time histories considered are the simple finite ramp and its first and second order continuous counterparts for rise times of 0.1, 0.25, and 0.5 seconds. Fault rupture propagation velocities are considered over the approximate range of from 2.0 kilometers/second to 2.5 kilometers/second.