Assessing whether the 2017 M w 5.4 Pohang earthquake in South Korea was an induced event

Abstract

Triggering quakes in a geothermal space Enhanced geothermal systems (EGSs) provide a potentially clean and abundant energy source. However, two magnitude-5 earthquakes recently occurred in South Korea during EGS site development. Grigoli et al. and Kim et al. present seismic and geophysical evidence that may implicate the second of these earthquakes, which occurred in Pohang, as an induced event. The combination of data from a local seismometer network, well logs, satellite observations, teleseismic waveform analysis, and stress modeling leads to the assessment that the earthquake was probably or almost certainly anthropogenically induced. The possibility remains that the earthquake occurred coincidentally at the EGS site location, but the aftershock distribution and other lines of evidence are concerning for future development of this geothermal resource. Science , this issue p. 1003 , p. 1007