  A high-resolution finite volume method approach to incorporating
time-dependent slip across rectangular subfaults when modeling general fault
geometry is presented. The fault slip is induced by a modification of the
Riemann problem to the linear elasticity equations across cell interfaces
aligned with the subfaults. This is illustrated in the context of the
high-resolution wave-propagation algorithms that are implemented in the open
source Clawpack software (www.clawpack.org), but this approach could be easily
incorporated into other Riemann solver based numerical methods. Surface
deformation results are obtained in both two and three dimensions and compared
to those given by the steady-state, homogeneous half-space Okada solution.
