


We use a
standard methodology in which regional distance ground motions recorded on
very broadband instruments are inverted for slip following the representation
theorem for an elastic dislocation.
We use a variety of simplifying assumptions including constant rupture
velocity and dislocation rise time.
We further apply slip positivity, seismic moment minimization and
smoothing constraints to provide stability to the inversion.




The simulation
of nearsource strong ground motions in our methodology involves either:


1. The application of a directivity capable
attenuation relationship such as that determined by Somerville et al. (1997)




2. Or solves the forward problem (above)
using Green’s functions appropriate for the nearsource region and the regionally derived fault slip map.




We will show
that a combination of 1 & 2 to produce a source specific conservative map
(largest value of the two methods) produces reasonable ground motions and is
found to work well when integrated with observed strong motion values
