The Earthquake Engineering Research Institute (EERI) and the U.S. Geological Survey (USGS) are pleased to announce the publication of a special collection of articles in Earthquake Spectra, EERI’s peer-reviewed journal, detailing the 2023 update of the United States National Seismic Hazard Model (NSHM). Additional papers on the 2023 national maps are also available in other peer reviewed journals, including from the Seismological Society of America; view a list here.
The 2023 NSHM is a comprehensive assessment of seismic hazard for all 50 states—it refines the previous model for the continental U.S. published in 2018, while integrating the first updates for Alaska since 2007 and for Hawaii since 1998. “This was a massive, multi-year collaborative effort between federal, state and local governments and the private sector,” said Mark Petersen, USGS geophysicist and project lead. “The new seismic hazard model represents a touchstone achievement for enhancing public safety.”
Significant updates to this model include refinements to input earthquake catalogs, refinement of approaches to develop earthquake rupture forecasts and ensure more uniform methodologies are used nationwide, enhanced consideration of sedimentary basins, and new ground motion models. The model incorporates new science on seismicity statistics, fault ruptures, ground motions, and probabilistic techniques, and aims to produce a standard of practice for public policy and engineering applications. “The model will have wide-ranging impacts to efforts such as building codes, regional risk assessments, communication efforts, and other safety plans and legislation,” said Spectra Editor-in-Chief Jack Baker.
The Spectra special collection is fully open access and features thirteen articles published to date, with additional forthcoming papers to be added. The articles include an overview of the project, a description of key models and inputs, and a summary of the hazard results, as well as papers on specific model components and supporting studies. The papers represent the collective work of dozens of authors, as well as insights and input from hundreds of additional contributors and from experts who provided formal reviews of project components to participants in more than 25 related workshops and public meetings.
The 2023 United States National Seismic Hazard Model Special Collection is available at the Earthquake Spectra website here—select the “Articles” tab to see all contents.
EERI-USGS Webinar Series: 2023 United States National Seismic Hazard Model
On April 30th and May 7th 2025, EERI and USGS will also present a two-part webinar series on the 2023 NSHM. The first webinar, on Wednesday April 30, will provide an overview of the science that went into the 2023 NSHM, including earthquake rupture forecasts, ground-motion characterization, and hazard modeling changes. The second webinar, on Wednesday May 7, will look at the engineering uses, including building code adoption, design ground motion standard, geohazards design guidelines, and earthquake loss estimates. Both webinars will take place from 11:00 AM-12:30 PM.
See the full list of speakers and a link to register here. Registering for the series will allow you to attend either or both sessions. To register, you will need to sign into your account on EERI’s new member portal. Non-members can register for the webinar by creating a free my.eeri.org account. Click the "Register to Attend" button on the event page and select the "create an account" option. Please contact us at
