The intensity signature of induced seismicity

We analyze a comprehensive database of ∼63,000">∼63,000 geocoded community intensity observations from >400">>400 earthquakes of moment magnitude M≥3.5">M≥3.5 in Oklahoma from 2010 to 2016 to define the intensity signature of induced events. We show that natural and induced events have similar average intensities within 10 km of the epicenter. At greater distances, induced events have low‐average intensities compared with deeper natural events. These trends are predictable based on ground‐motion prediction equations. They are a consequence of two focal‐depth effects that have offsetting impacts on the strength of ground motion: (1) the epicenter is near the source for shallow events, and (2) the stress parameter scales with focal depth.