The development of this velocity and strain rate model is discussed in the following publication: Smith-Konter, B., D. T. Sandwell, Stress evolution of the San Andreas Fault System: recurrence interval versus locking depth, Geophys. Res., Lett., 35, L13304, doi:10.1029/2009GL037235, 2009.

One aditional step in the model construction is to compute the difference between the GPS velocities and the model velocities.  These are gridded using a buharmonic spline program and the results are added to the mode velocity to
form a total velocity that both conforms to the model and fist the GPS data.

Bridget Smith-Konter
September 2009