We develop a generic finite‐fault source model for simulation of large earthquakes: the distributed slip model (DSM). Six geometric and seven kinematic parameters are used to describe a smooth pseudo‐Gaussian slip distribution, such that slip decays from peak slip within an elliptical rupture patch to zero at the borders of the patch. The DSM is implemented to initiate seismic‐wave propagation in a finite‐difference code.
Radiation pattern and spectral characteristics of the DSM are compared with those of commonly used finite‐fault models, that is, the classical Haskell’s model (HM) and the modified HM with radial rupture propagation (HM‐RRP). The DSM accounts for directivity effects in the fault‐parallel direction, as well as fault‐normal ground motions, and overcomes the unrealistic uniform slip and stress singularities of the Haskell‐type models.
We show the potential of the DSM to estimate the ground motions of strong earthquakes. We use this model to initiate seismic‐wave propagation during the 1927 ML 6.25 Jericho earthquake and compare calculated macroseismic intensities to reported intensities at 122 localities. The root mean square of intensity residuals is 0.68, with 56% of the calculated intensities matching the reported intensities and 98% of the calculated intensities within a single unit from the reported intensities. The DSM is an essential step toward robust ground‐motion prediction in earthquake‐prone regions with a long return period and limited instrumental coverage.
Online Material: Animation of rupture and wave propagation.