Ground‐Motion Prediction Equation for Small‐to‐Moderate Events at Short Hypocentral Distances, with Application to Induced‐Seismicity Hazards

Abstract The evaluation of seismic hazard from induced seismicity requires the development of ground‐motion prediction equations (GMPEs) that are tuned to the key magnitude–distance range for such applications. I use events of M  3–6 at hypocentral distances less than 40 km, drawn from the Next Generation Attenuation‐West 2 (NGA‐West 2) database, to develop a GMPE that accounts correctly for point‐source scaling in both magnitude and distance space for such events. The developed GMPE is in demonstrable agreement with the NGA‐West 2 database and with the predictions of a stochastic point‐source simulation model. The database is sparse at close distances, implying epistemic uncertainty of as much as a factor of 2 in ground‐motion amplitudes within 10 km of the hypocenter. An important conclusion from this study is that the ground‐motion amplitudes for moderate induced events could be much larger near the epicenter than predicted by most of the NGA‐West 2 GMPEs. The potential for large motions is a consequence of the shallow depth of induced events, which places the earthquake fault only a short distance beneath the epicenter.