Exciting news! We're transitioning to the Statewide California Earthquake Center. Our new website is under construction, but we'll continue using this website for SCEC business in the meantime. We're also archiving the Southern Center site to preserve its rich history. A new and improved platform is coming soon!

The USGS 2023 Conterminous U.S. Time‐Independent Earthquake Rupture Forecast

Edward H. Field, Kevin R. Milner, Alex Hatem, Peter M. Powers, Fred F. Pollitz, Andrea L. Llenos, Yuehua Zeng, Kaj M. Johnson, Bruce E. Shaw, Devin McPhillips, & . et al

Published December 22, 2023, SCEC Contribution #13392

We present the 2023 U.S. Geological Survey time‐independent earthquake rupture forecast for the conterminous United States, which gives authoritative estimates of the magnitude, location, and time‐averaged frequency of potentially damaging earthquakes throughout the region. In addition to updating virtually all model components, a major focus has been to provide a better representation of epistemic uncertainties. For example, we have improved the representation of multifault ruptures, both in terms of allowing more and less fault connectivity than in the previous models, and in sweeping over a broader range of viable models. An unprecedented level of diagnostic information has been provided for assessing the model, and the development was overseen by a 19‐member participatory review panel. Although we believe the new model embodies significant improvements and represents the best available science, we also discuss potential model limitations, including the applicability of logic tree branch weights with respect different types of hazard and risk metrics. Future improvements are also discussed, with deformation model enhancements being particularly worthy of pursuit, as well as better representation of sampling errors in the gridded seismicity components. We also plan to add time‐dependent components, and assess implications with a wider range of hazard and risk metrics.

Field, E. H., Milner, K. R., Hatem, A., Powers, P. M., Pollitz, F. F., Llenos, A. L., Zeng, Y., Johnson, K. M., Shaw, B. E., McPhillips, D., & et al, .. (2023). The USGS 2023 Conterminous U.S. Time‐Independent Earthquake Rupture Forecast. Bulletin of the Seismological Society of America,. doi: 10.1785/0120230120.