UCLA

The 2025 update of the National Seismic Hazard Model (NSHM) for Puerto Rico and the Virgin Islands (PRVI) replaces a previous version of the model from 2003. The 2025 update has two major components – a seismic source characterization (SSC) model and a ground motion characterization (GMC) model. In August 2024, the Steering Committee for the NSHM formed this Panel to review the GMC component of the NSHM work for PRVI. The panel is advisory, meaning that we provide input on technical issues for consideration by the Steering Committee and the USGS NSHM team, but we do not have decision making authority. Final modeling decisions are presented in separate USGS documents, including Shumway et al. (2025), Moschetti et al. (2025), Moschetti (2025), and Withers et al. (2025). Where modeling decisions depart from our recommendations, the rationale is explained in those publications.