9706122 Rockwell This research is to continue paleoseismic excavations at a site on the central Garlock fault in southern California that could potentially provide a longer record of prehistoric earthquakes than any site studied and published to date. A long record of prehistoric earthquakes is critical for determining the distribution of earthquake recurrence intervals along faults and for placing constraints on physical models of earthquake recurrence. In prior work, these scientists showed that the central Garlock fault has produced 5-8 large earthquakes in the past 5145 years, on average at intervals of 700-1230 years. The radiocarbon ages of earthquakes exposed in the initial trench indicate that the recurrence intervals for the central Garlock fault are irregular and that earthquakes may be clustered in time. This research will extend the earthquake record to 10-15 large earthquakes and better document the timing of all events. This research is a component of the National Earthquake Hazard Reduction Program. ***
