WOLF, RICH, Division of Geological & Planetary Sciences, California, Institute of Technology, Pasadena, CA, and KENNETH W. HUDNUT, U.S. Geological Survey, Pasadena, CA
ABSTRACT: A Review of Recent Crustal Deformation Studies in the Southern California Borderland Region
Empirical observation and modeling of the deformation field has created a consensus among geophysicists that the relative plate motion in the southern California borderland region, southwest of the San Andreas fault, is approximately 5 +/-1 mm/yr. For instance, analysis and revision of VLBI and GPS data sets have shown that the Vandenberg GPS site moves at nearly the full Pacific-plate rate as predicted by the NUVEL-1 plate tectonic model (47-48 mm/yr). Furthermore, recent studies have documented deformation across the Santa Barbara Channel, the Ventura basin, and the Los Angeles basin, as well as the region surrounding the southern Channel Islands. These studies show that the spatial distribution of deformation across the borderland is complex, and since the rates of motion are relat vely low, the task of calculating individual rates across varying fault zones is a challenging one. Moreover, much of the work to date relies on historical survey data, and the comparison of GPS results to these data obtained from historical trilateration, triangulation, and leveling surveys has been difficult as well. Nonetheless, research continues in order to provide better constraints for earthquake hazards and a better understanding of the active tectonics in this region.
AAPG Search and
Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach,
California, May 5-7, 1993.