SLIP RATE, EARTHQUAKE RECURRENCE, AND SEISMOGENIC POTENTIAL OF THE RODGERS CREEK FAULT ZONE, NORTHERN CALIFORNIA - INITIAL RESULTS

Instrumental seismicity defines a seismic gap along the Rodgers Creek fault zone (RCFZ) between Santa Rosa and San Pablo Bay. Results of a paleoseismicity study within the gap, using offset channels in late Holocene alluvial deposits as piercing points, indicate a minimum slip rate of 2.1 to 5.8 mm/yr for the past 1300 years, a preferred range for the maximum recurrence interval of 248 to 679 years, and a surface offset of 2 +0.3,-0.2 m during the most recent event. The RCFZ has produced past M7 earthquakes, and historical seismicity data indicate a minimum elapsed time of 182 years since the most recent earthquake of this size.