The Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3)—The Time-Independent Model 42ºN 38ºN 34ºN M ≥ 6.7 Earthquake Participation Rates (per year) 10 -6 10 -4 10-2 122°W 120°W 118°W USGS Open-File Report 2013–1165 CGS Special Report 228 Southern California Earthquake Center Publication 1792 U.S. Department of the Interior U.S. Geological Survey COVER 3D perspective view of California, showing the average long-term rate at which different areas of the state participate in M≥6.7 earthquake ruptures. Black rectangles represent explicitly modeled faults (for UCERF3 Fault Model 3.1). Ruptures associated with the Cascadia megathrust are not shown. Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3)—The Time-Independent Model By Edward H. Field, Glenn P. Biasi, Peter Bird, Timothy E. Dawson, Karen R. Felzer, David D. Jackson, Kaj M. Johnson, Thomas H. Jordan, Christopher Madden, Andrew J. Michael, Kevin R. Milner, Morgan T. Page, Tom Parsons, Peter M. Powers, Bruce E. Shaw, Wayne R. Thatcher, Ray J. Weldon, II, and Yuehua Zeng (Working Group on California Earthquake Probabilities) U.S. Geological Survey Open-File Report 2013–1165 California Geological Survey Special Report 228 Southern California Earthquake Center Publication 1792 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia 2013 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Suggested citation: Field, E.H., Biasi, G.P., Bird, P., Dawson, T.E., Felzer, K.R., Jackson, D.D., Johnson, K.M., Jordan, T.H., Madden, C., Michael, A.J., Milner, K.R., Page, M.T., Parsons, T., Powers, P.M., Shaw, B.E., Thatcher, W.R., Weldon, R.J., II, and Zeng, Y., 2013, Uniform California earthquake rupture forecast, version 3 (UCERF3)—The time-independent model: U.S. Geological Survey Open-File Report 2013–1165, 97 p., California Geological Survey Special Report 228, and Southern California Earthquake Center Publication 1792, http://pubs.usgs.gov/of/2013/1165/. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. STATE OF CALIFORNIA EDMUND G. BROWN JR. GOVERNOR THE NATURAL RESOURCES AGENCY JOHN LAIRD SECRETARY FOR NATURAL RESOURCES DEPARTMENT OF CONSERVATION MARK NECHODOM DIRECTOR CALIFORNIA GEOLOGICAL SURVEY JOHN G. PARRISH, Ph.D. STATE GEOLOGIST This page intentionally left blank. Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3)—The Time-Independent Model Table of Contents List of Abbreviations Used in this Report....................................................................................................................... ix Contributors to UCERF3 ................................................................................................................................................ x Executive Committee (ExCom) ................................................................................................................................... x Key Contributors ......................................................................................................................................................... x Management Oversight Committee (MOC) ................................................................................................................ x Scientific Review Panel (SRP) ................................................................................................................................... xi UCERF3 Deformation Model Evaluation Committee ................................................................................................. xi California Earthquake Authority Multidisciplinary Research Team ............................................................................ xi External Evaluation of UCERF3 ................................................................................................................................ xii Abstract .......................................................................................................................................................................... 1 Introduction .................................................................................................................................................................... 2 Background ................................................................................................................................................................ 2 Model Framework ....................................................................................................................................................... 5 Model Uncertainties .................................................................................................................................................... 7 Participants, Review, and Consensus Building ........................................................................................................... 8 Fault Models................................................................................................................................................................. 11 Definition .................................................................................................................................................................. 11 Fault Zone Polygons ................................................................................................................................................. 11 Logic Tree Branches ................................................................................................................................................ 12 Development Process .............................................................................................................................................. 12 Deformation Models ..................................................................................................................................................... 15 Geologic Slip Rate Constraints ................................................................................................................................. 15 Geologic Deformation Model .................................................................................................................................... 16 Deformation Models from Joint Inversion of Geodetic and Geologic Data ............................................................... 17 Creep and Aseismicity .............................................................................................................................................. 19 Implied Moment Rates .............................................................................................................................................. 22 Logic Tree Branch Weights ...................................................................................................................................... 26 Earthquake Rate Models and the “Grand Inversion” .................................................................................................... 26 Methodology ............................................................................................................................................................. 27 Implementation Ingredients ...................................................................................................................................... 29 Inversion Setup and Associated Gridded Seismicity ................................................................................................ 41 Gardner-Knopoff Aftershock Filter ............................................................................................................................ 49 Results ..................................................................................................................................................................... 50 Sensitivity Tests........................................................................................................................................................ 80 Discussion .................................................................................................................................................................... 84 Improvements Over UCERF2 ................................................................................................................................... 85 Model Limitations ...................................................................................................................................................... 87 Future Improvements ............................................................................................................................................... 89 Conclusions and Recommendations ............................................................................................................................ 90 Acknowledgements