The SEA99 Ground-Motion Predictive Relations for Extensional Tectonic Regimes: Revisions and a New Peak Ground Velocity Relation

The values of r3 listed in table 1 of Pankow and Pech-mann (2004) are too large by a factor of Z2 because they were calculated using equation (3) of Boore et al. (1993), which has an error in it as reported by Boore (2005) and Spudich and Boore (2005). The r3 for the peak ground ve-locity (PGV) should be changed from 0.106 to 0.075. The rest of the r3 values are originally from table 2 of Spudich et al. (1999), and their corrections are discussed in Spudich and Boore (2005). The r3 values are needed for calculating the standard deviation of the ground-motion prediction for a randomly oriented horizontal component. The results for the horizontal-component geometric mean are unaffected by the error. References Boore, D. M. (2005). Erratum: Equations for estimating horizontal response spectra and peak acceleration from western North American earth-quakes: a summary of recent work, Seism. Res. Lett. 76, 368–369