Assessing the Impact of Additional Seismic Sources on the Probabilistic Seismic Hazard Assessment for the Las Vegas Valley, Nevada

Introduction • The densely populated (~2M) Las Vegas Valley, Nevada (LVV) is underlain by sediments that are cut by six mapped, active normal faults that comprise the Las Vegas Valley Fault System (LVVFS). Recent research indicates that these faults have the potential to generate earthquakes up to a maximum magnitude of 6.8. • The current (2008) USGS national seismic hazard model (NSHM) explicitly considered only the Eglington fault of the LVVFS (the remaining 5 LVVFS sources were classified as "Class B" in the USGS fault and fold database and effectively given a weight of zero in the 2008 NSHM) and also did not consider four regional faults outside of the LVV due to insufficient documentation. • We conducted a probabilistic seismic hazard analysis (PSHA) for rock-site conditions for the LVV that included consideration of these eight faults and modified properties of two others with respect to the 2008 USGS NSHM.