Numerical simulations of tectonic processes in Southern California

Summary. A relaxation model for crustal tectonics, using the Finite Element method, was developed and applied to the region of Southern California. Both the existence of the Transverse Ranges and the geometry of the San Andreas fault in the region of Southern California, imply a stress pattern deviating from the simple horizontal shear which parallels the spreading between the Pacific and the North American plates. A number of possible mechanisms responsible for this anomalous stress field were examined quantitatively in the light of seismicity and other tectonic observations, and in particular to the Palmdale uplift which was reported to have occurred between the years 1960–65.