Earthquake Spectra recently launched a new special collection of 13 articles based on the work of the Fault Displacement Hazard Initiative (FDHI), led by Yousef Bozorgnia (M.EERI 1986), professor of Civil and Environmental Engineering and founding Director of the Natural Hazards Risk and Resiliency Research Center (NHR3) at the University of California, Los Angeles. Findings from this special collection will also be presented in a special session at the 13th National Conference on Earthquake Engineering (13NCEE) in Portland next summer.
This Fault Displacement Hazard Initiative (FDHI) was a multi-year collaborative research program that developed a global database of surface fault displacement measurements and four new fault displacement models (FDMs). This Special Collection contains papers documenting the FDHI project, the database, supplementary studies, and the new fault displacement models.
The FDHI Database contains systematically collected and quality-assured data from 75 surface-rupturing earthquakes (M 4.9-8.0) spanning all faulting styles. Using this database, modeling teams developed FDMs that predict either principal displacement on individual ruptures or aggregate displacement combined across principal and distributed ruptures. Two models apply to all faulting styles while two are for reverse or strike-slip faulting. The models utilize various statistical distributions and data transformations to improve upon previous predictions of fault displacement characteristics. Compared to earlier models, the FDHI FDMs produce average displacements about 40% higher for M ~7 earthquakes but predict smaller displacements at both lower and higher magnitudes. The models incorporate nonlinear magnitude scaling and improved aleatory variability treatment, with upper tail predictions showing reasonable agreement with empirical maximum displacement observations. This supports their application in probabilistic fault displacement hazard analysis at long return periods.
The 13 papers in this special collection are available to EERI members and Spectra subscribers at the collection page here.
