High-resolution seismic data from the Frijoles Fault of the San Gregorio Fault zone, Año Nuevo, California
Description
The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at Año Nuevo, California in 2012. The SGFZ is a Holocene-active, dominantly right-lateral fault system that trends more than 200 km along the California coastline. The Frijoles Fault is one of several onshore strands of the SGF system, and together the strands represent a 3- to 4-km wide fault zone at Año Nuevo. Prior paleoseismology studies indicate highly variable slip-rate estimates, indicating considerable uncertainty about the slip history of the SGFZ and the seismic hazard it poses. Amongst the onshore strands of the SGFZ at Año Nuevo, the Frijoles Fault presented the fewest logistical challenges for our seismic survey; thus, the goal of this data acquisition was to better understand the structure, geometry, and precise location of the Frijoles Fault strand of the SGFZ at Año Nuevo.