Probabilistic Seismic Hazard Analysis in California Using Nonergodic Ground Motion Models

Research Article| July 02, 2019 Probabilistic Seismic Hazard Analysis in California Using Nonergodic Ground‐Motion Models Norman A. Abrahamson; Norman A. Abrahamson aDepartment of Civil Engineering, University of California, Berkeley, 447 Davis Hall, Berkeley, California 94720‐1792 U.S.A. Search for other works by this author on: GSW Google Scholar Nicolas M. Kuehn; Nicolas M. Kuehn Corresponding Author bB. John Garrick Institute for the Risk Sciences, University of California, Los Angeles, Engineering VI 5th Floor, 404 Westwood Plaza, Los Angeles, California 90095 U.S.A., kuehn@ucla.edueAlso at Richmond Field Station, Building 451, Office 22, 1301 S. 46th Street, Richmond, California 94804‐4698 U.S.A. Search for other works by this author on: GSW Google Scholar Melanie Walling; Melanie Walling cGeoEngineers Inc., 17425 NE Union Hill Road Suite 250, Redmond, Washington 98052 U.S.A. Search for other works by this author on: GSW Google Scholar Niels Landwehr Niels Landwehr dLeibniz Institute for Agricultural Engineering and Bioeconomy Potsdam‐Bornim, Max‐Eyth‐Allee 100, 14469 Potsdam, Germany Search for other works by this author on: GSW Google Scholar Bulletin of the Seismological Society of America (2019) 109 (4): 1235–1249. https://doi.org/10.1785/0120190030 Article history first online: 02 Jul 2019 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Norman A. Abrahamson, Nicolas M. Kuehn, Melanie Walling, Niels Landwehr; Probabilistic Seismic Hazard Analysis in California Using Nonergodic Ground‐Motion Models. Bulletin of the Seismological Society of America 2019;; 109 (4): 1235–1249. doi: https://doi.org/10.1785/0120190030 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 SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract With an increasing number of strong‐motion records over the past decade, it has become clear that there are significant differences in ground‐motion scaling even within relatively small regions such as California. These differences are not modeled in typical ground‐motion models (GMMs) that are based on the ergodic assumption. By including systematic source, path, and site effects in fully nonergodic GMMs, it is possible to reduce the value of the aleatory variability by about 30%–40%; however, to use this reduced aleatory variability, it is important to account for the epistemic uncertainty in the nonergodic terms.We build a nonergodic GMM for California that explicitly accounts for nonergodic source, path, and site effects by combining the results and methods outlined by Dawood and Rodriguez‐Marek (2013) and Landwehr et al. (2016). The deviation of the systematic terms form the ergodic mean is constrained by observed ground‐motion data. The uncertainty of the systematic terms is tracked and explicitly taken into account. The uncertainty becomes small in the vicinity of observed data and large in regions that lack data. We calculate seismic hazard for three different sites in California using the nonergodic GMM. The results show that the mean hazard can change significantly for sites that have data in the vicinity compared to an ergodic hazard analysis, whereas the epistemic uncertainty associated with hazard results increases for sites with no observed data as compared to the ergodic approach. This presents the first fully nonergodic seismic hazard analysis with the systematic effects based on observed ground‐motion and fully including their uncertainty. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.