In areas with sparse seismicity such as the central and eastern United States (CEUS), the peak ground motions expected over time periods of years to decades are typically dominated by regional-distance (>100 km) surface waves (Petersen et al., 2014). Nevertheless, there are large differences in the decay of seismic energy with distance from the hypocenter-termed seismic attenuation-across the continental United States (e.g.