Seismic strain rates in the Central and Eastern United States

Seismic strain rates for the entire Central and Eastern United States are estimated from historical seismicity and from several seismicity models. Typical strain rates are estimated to be the on the order of 10−12 to 10−11 per year, except near historical sites of large earthquakes where higher rates pertain. Uncertainties in strain rates are large. Deformation caused by strain rates less than 10−10 yr−1 is very small compared to average denudation rates. Denudation and deposition may control the rate of earthquake occurrence in some parts of the Central and Eastern United States by modifying the vertical stress due to load. A simple quantitative model predicts the earthquake occurrence rate in the Appalachian Mountains from an estimate of the regional denudation rate.