9706690 Kellogg Using a combination of Global Positioning System (GPS) measurements, historical data, and viscoelastic modeling, The PI will determine the deformation on the White Wolf Fault, southern California. This fault was responsible for the 1952 Kern County Earthquake (magnitude 7.8). The research plan includes: (1) reoccupation of the previously studied geodetic network to establish the long-term deformation rates and examine the effects of the Northridge earthquake; (2) occupation of geodetic sites near the northern end of the fault to determine the strain associated with seismic activity in this region; (3) analysis of available geodetic data from 1952 and 1953 to determine the deformation associated with the Kern county earthquake, and (4) simulation of the deformation using a numerical model of a faulted, viscoelastic medium to determine the crustal rheology. ***