Summary of UCERF3 (see Madden et al., 2013) database by event age; historic versus prehistoric (Madden et al., 2013). EQ—earthquake. (A) Measurement methods for historic earthquakes (EQ). (B) Number of offset measurements (blue) versus unique geographic sites (red) for historic earthquakes. (C) Measurement methods for prehistoric earthquakes. (D) Number of offset measurements (blue) versus unique geographic sites (red) for prehistoric earthquakes. *NFTS—North Frontal thrust system.