Analysis of Mean Seismic Ground Motion and Its Uncertainty Based on the UCERF3 Geologic Slip‐Rate Uncertainty for California

Abstract

Research Article| April 25, 2018 Analysis of Mean Seismic Ground Motion and Its Uncertainty Based on the UCERF3 Geologic Slip‐Rate Uncertainty for California Yuehua Zeng Yuehua Zeng aUSGS Geologic Hazards Science Center, MS 966, Box 25046, Denver, Colorado 80225 U.S.A., zeng@usgs.gov Search for other works by this author on: GSW Google Scholar Author and Article Information Yuehua Zeng aUSGS Geologic Hazards Science Center, MS 966, Box 25046, Denver, Colorado 80225 U.S.A., zeng@usgs.gov Publisher: Seismological Society of America First Online: 25 Apr 2018 Online Issn: 1938-2057 Print Issn: 0895-0695 © Seismological Society of America Seismological Research Letters (2018) 89 (4): 1410–1419. https://doi.org/10.1785/0220170114 Article history First Online: 25 Apr 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Yuehua Zeng; Analysis of Mean Seismic Ground Motion and Its Uncertainty Based on the UCERF3 Geologic Slip‐Rate Uncertainty for California. Seismological Research Letters 2018;; 89 (4): 1410–1419. doi: https://doi.org/10.1785/0220170114 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search ABSTRACT The Uniform California Earthquake Rupture Forecast v.3 (UCERF3) model (Field et al., 2014) considers epistemic uncertainty in fault‐slip rate via the inclusion of multiple rate models based on geologic and/or geodetic data. However, these slip rates are commonly clustered about their mean value and do not reflect the broader distribution of possible rates and associated probabilities. Here, we consider both a double‐truncated 2σ Gaussian and a boxcar distribution of slip rates and use a Monte Carlo simulation to sample the entire range of the distribution for California fault‐slip rates. We compute the seismic hazard following the methodology and logic‐tree branch weights applied to the 2014 national seismic hazard model (NSHM) for the western U.S. region (Petersen et al., 2014, 2015). By applying a new approach developed in this study to the probabilistic seismic hazard analysis (PSHA) using precomputed rates of exceedance from each fault as a Green’s function, we reduce the computer time by about 105‐fold and apply it to the mean PSHA estimates with 1000 Monte Carlo samples of fault‐slip rates to compare with results calculated using only the mean or preferred slip rates. The difference in the mean probabilistic peak ground motion corresponding to a 2% in 50‐yr probability of exceedance is less than 1% on average over all of California for both the Gaussian and boxcar probability distributions for slip‐rate uncertainty but reaches about 18% in areas near faults compared with that calculated using the mean or preferred slip rates. The average uncertainties in 1σ peak ground‐motion level are 5.5% and 7.3% of the mean with the relative maximum uncertainties of 53% and 63% for the Gaussian and boxcar probability density function (PDF), respectively. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.