Extrapolation of populations of small earthquakes to predict consequences of low- probability high impact events: The Pohang case study revisited

•Magnitudes of earthquakes for the Pohang EGS project are underestimated.•Reason one is the low Nyquist frequency of digital recording at regional stations•Reason two is miscalibration of the local magnitude scale in Korea.•Reason three is miscalibration of magnitude estimation by ‘template matching’.•Accurate magnitudes and b-values are essential for interpretation of EGS seismicity.