Seismic Source Characterization for Greater Phoenix Area Earthquake Hazard

Abstract

We have developed a model for active seismogenic faults for the greater Phoenix area. The Quaternary geologic record was used to delineate the local seismic sources, assess potential earthquake size, and estimate earthquake recurrence to support an integrated regional probabilistic evaluation of the seismic hazard. The probabilistic seismic hazard analysis is summarized as uniform hazard spectra and contour maps of peak ground acceleration and spectral acceleration at one second for weak rock site conditions at two percent probability of exceedance in 50 years. As building codes typically allow some level of reduction in design spectral accelerations from values obtained from the National Seismic Hazard Maps, we compared our results to values obtained from the National Seismic Hazard Maps. No reduction in building code seismic design requirements is justified in the areas addressed herein on the basis of our site specific analysis.