Characterizing injection-induced seismicity in the United States
Injection-induced seismicity is frequently characterized by swarms of low magnitude earthquakes. The identification of these small magnitude earthquakes can greatly aid our understanding of induced seismicity, but traditional earthquake detection approaches struggle to identify these earthquakes with low signal-to-noise ratios. The Repeating Signal Detector (RSD) algorithm was created to increase the detection sensitivity of earthquakes swarms on both the local and regional scale. RSD can quickly identify low magnitude, repeating earthquakes buried within years of seismic records by grouping signals based on spectral and time domain characteristics. The identification of a characteristic repeating waveform, the primary limitation of seismic waveform template matching, is also addressed through the use of RSD. By using RSD and multi-station template matching to improve the completeness of earthquake catalogs in the United States, we are able to better characterize injection-induced earthquake sequences. We find that the likelihood of injection-induced earthquakes is primarily controlled by the proximity of injection to the Precambrian basement, and seismicity induced by hydraulic fracturing is much more common than previously recognized.