Revisions to the 2023 U.S. 50‐State National Seismic Hazard Model

We present an update to the 2023 U.S. 50‐state National Seismic Hazard Model, based on questions and comments received from a range of users, as well as additional internal and building code reviews since its initial release. For the conterminous United States, the update includes (1) revised weighting of ground motion models in the Intermountain West, (2) revised weighting of seismicity models across the stable crust of the central and eastern United States, (3) corrections to fault rupture input files and hazard codes, and (4) adjustments to stable crust nonlinear site amplification terms at soft soil sites. The model also updates the implementation of moment magnitude 7–8 subduction interface earthquake ruptures for Alaska and includes an alternate, full‐catalog rate model for Hawaii. The revised model is available through the U.S. Geological Survey online tools and is accompanied by a data release of high‐resolution hazard datasets for eight site conditions (from soft soil to hard rock with a time‐averaged shear‐wave velocity, V S30 , ranging from 150 to 1500 m/s) in terms of peak horizontal ground acceleration, peak ground velocity, and 5% damped pseudo‐spectral accelerations at 21 spectral periods. It has been approved as the basis for updated design provisions and is being considered for inclusion in other hazard and risk assessment products.