Seismicity Associated with Geothermal Systems

Studying natural and induced seismicity associated with geothermal systems can provide information regarding the location and magnitude of hydraulic fracturing. Understanding the fracture system can aid geothermal exploration. In addition, seismicity can affect the output of a geothermal reservoir, and potentially be a seismic hazard to the surrounding area. This study focuses on two geothermal systems: the Raft River Geothermal System (RRGS) in southern Idaho and the Mt. Princeton Geothermal System (MPGS) in central Colorado. The seismic data analyzed for the RRGS is from the broadband sensors that are part of the EarthScope Project’s Transportable Array (TA), while the seismic data from the MPGS is from broadband and short-period sensors from the IRIS PASSCAL Instrument Center. A significant increase in seismic activity was measured on the TA station L14A near the RRGS, indicating pump testing and production caused induced seismicity. At MPGS, local events were identified, possibly related to natural hydraulic fracturing caused by near-surface hot fluid movement