New Seismic Hazard Research Capabilities and Software Improvements in OpenSHA v26.8

Akash Bhatthal, Kevin R. Milner, Scott Callaghan, & Ahmed E. Elbanna

Submitted August 30, 2026, SCEC Contribution #15563, 2026 SCEC Annual Meeting Poster #204

OpenSHA is an open-source, SCEC- and USGS-developed tool for performing seismic hazard analysis. Over the past year, OpenSHA has continued to advance its seismic hazard analysis capabilities, culminating in the release of version 26.8 which includes both new scientific and technical enhancements.

Version 26.8 includes updates to U.S. National Seismic Hazard Models (NSHMs) in OpenSHA applications. The 2025 NSHM for Puerto Rico and the U.S. Virgin Islands is now available, as well as revision 2 of the 2023 NSHM for the western U.S. Both models now support tectonic-regime-specific ground motion model (GMM) assignment, and the GMMs developed for each included tectonic regime in NSHM23 and NSHM25 are available.

Additional site data providers are now available, including basin depth and sediment thickness for the Conterminous U.S. from the 2023 and 2018 NSHMs, and basin depth for California from the Multi-Scale California (MUSCAL) basin depth velocity model.

This release marks a platform-wide upgrade from Java 11 to Java 21. This modernization ensures the platform's continued support as Java 11 reaches its end-of-life, while enabling the use of modern language features to enhance both performance and maintainability. To streamline software accessibility, OpenSHA v26.8 debuts native hosting on the Maven Central Repository under the org.opensha namespace, allowing researchers and developers to import the platform directly into Gradle and Maven projects without managing fat JARs. For end-users, a new built-in Application Updater Subsystem automatically detects stable updates on startup, providing seamless single-click updates, release note summaries, and configurable deferral options.

Key Words
opensha,nshm23,nshm25,seismic hazard analysis, velocity models

Citation
Bhatthal, A., Milner, K. R., Callaghan, S., & Elbanna, A. E. (2026, 08). New Seismic Hazard Research Capabilities and Software Improvements in OpenSHA v26.8. Poster Presentation at 2026 SCEC Annual Meeting.

Related Projects & Working Groups
Research Computing (RC)