Optimizing multi-station earthquake template matching through re-examination of the Youngstown, Ohio, sequence

- Optimized template matching identified 566 induced earthquakes in Youngstown, OH.
- Seismicity propagated ∼1 km in a direction consistent with the fault plane solution.
- Seismicity began after injection started and abruptly reduction when injection ceased.
- b-values are consistent with hydraulic fracturing near the beginning of injection.

A series of earthquakes in 2011 near Youngstown, OH, has been a focal point for discussions of seismicity induced by a nearby wastewater disposal well. Utilizing an efficient waveform template matching procedure, the optimal correlation template to study the Youngstown sequence was identified by varying parameters such as the stations utilized, frequency passband, and seismogram length. A catalog composed of 566 events was identified between January 2011 and February 2014. Double-difference relocation refines seismicity to a ∼800 m linear streak from the Northstar 1 injection well to the WSW along the same strike as the fault plane of the largest event. Calculated Gutenberg-Richter b-values are consistent with trends observed in other regions with seismicity induced by fluid injection.