Investigating the spatial and temporal distribution of earthquakes and tremor along the Cholame segment of the San Andreas fault

The Parkfield Experiment to Record MIcroseismicity and Tremor (PERMIT) is a thirteen-station broadband array deployed between May 2010 and July 2011 near Cholame, California, to improve seismic network coverage south of the High Resolution Seismic Network (HRSN). The array is located along a portion of the San Andreas fault that transitions from locked to creeping northward along fault strike. The goal of the project is to explore the spatiotemporal relationships between low-frequency earthquakes (LFEs) and local earthquake activity reported in the Northern California Seismic Network (NCSN) catalog and identified in the temporary array data. We identify LFEs from a catalog of tremor episodes automatically detected using a neural network approach. Previous studies have shown that tremor activity increased along this section of the San Andreas fault before and after the 2004 Parkfield earthquake, suggesting that stress interactions exist between earthquakes in the shallow, seismogenic zone and processes in the deeper transition zone. Understanding the range of fault slip behaviors, including how tremor and earthquakes interact, will provide critical information for assessing seismic hazard.