Fault creep in central California



Since its initial recognition twelve years ago, fault creep has been found to be occurring at a number of localities in California. Evidence for fault creep has now been observed along the Hayward-Calaveras fault from Richmond to Hollister and along the San Andreas fault system from San Juan Bautista to Cholame. On the San Andreas fault the active fault slippage is occurring where there has not been large offset in a major earthquake in historic time. San Juan Bautista is at the southern end of fault breakage in the earthquake of 1906, and Cholame, with some historical uncertainty, is at the northern end of fault breakage in the earthquake of 1857. The situation is different on the Hayward fault, where the fault slippage is found both within and beyond the ends of the segment that faulted in the earthquake of 1868.