Application of DInSAR-GPS optimization for derivation of three-dimensional surface motion of the southern California region along the San Andreas fault

We present here a methodology that allows the combination of GPS and Differential InSAR data for the calculation of continuous three-dimensional (3D) high-resolution velocity maps with corresponding errors. It is based on analytic minimization of the Gibbs energy function, which is possible in the case when neighborhood pixels of the velocity maps are considered independent. By joining scalar DInSAR data and vector GPS data, the technique allows us to achieve significant improvement in accuracy in the components of the velocity vector in comparison with the GPS data alone. In the accompanying example, the method is used for the investigation of the creep motion of the southern San Andreas fault around the Salton Sea region. The velocity maps are calculated for two time periods (1992-1998 and 1997-2001) and also for 3D and 2D cases. The preliminary analysis of the optimized data suggests that creep on the San Andreas fault in this region is time-dependent. (C) 2007 Elsevier Ltd. All rights reserved.