High-resolution seismic data acquired near seismic station CE.57213 in Fremont, California

In September 2021, the U.S. Geological Survey acquired high-resolution P- and S-wave data near seismic station CE.57213 in Fremont, California, approximately 100 m east of the mapped trace of the Hayward Fault. We acquired the seismic data to evaluate the time-averaged shear-wave velocity in the upper 30 m (VS30) and to better understand ground-shaking near the station CE.57213. The seismic data were acquired using a linear array of SmartSolo 3-component nodal seismometers (nodes), which continuously recorded at 2000 samples per second (0.5-ms sampling rate). We deployed 60 nodes, spaced at 2-m increments, along a 180-m-long, northeast-southwest-trending linear array. We generated P-wave seismic sources (shots) adjacent to each node at a 1-m offset using a 3.5-kg sledgehammer to vertically strike a steel plate on the ground surface. S-wave sources (shots) were generated adjacent to each node by horizontally striking an aluminum block with a 3.5-kg sledgehammer. For each shot point, we extracted approximately 2 seconds of data from each node following the shot times, combined the seismic traces into a single shot gather, and stored the data in SEG-Y format (Barry et al, 1975). This report provides the metadata needed to analyze the seismic data.