Impacts on Network Infrastructure Performance Assessments from Multi-Segment and Multi-Fault Ruptures in UCERF3

Session: Forthcoming Updates of the USGS NSHMs: Hawaii, Conterminous U.S. and Alaska [Poster]
Type: Poster
Date: 4/28/2020
Time: 08:00 AM
Room: Ballroom
Description: 

One of the influential modeling assumptions in Version 3 of the Uniform California Earthquake Rupture Forecast (UCERF3) [Field et al., 2013] is that relaxation of fault segmentation allows multi-segment and multi-fault ruptures. Utilizing this assumption results in more larger-magnitude and longer-length ruptures in the system than were in the previous model (UCERF2). Lee (2019) examined the impact that super long ruptures (greater than 500 km up to 1200 km) along the San Andreas Fault made to seismic risk assessments for a state-wide real estate portfolio in California. The results showed that these long ruptures made significant contributions to earthquake risks. In this study, the influence of the multi-fault ruptures on system-level seismic risks for a large local water pipeline network in Southern California is examined. Southern California is a complex seismotectonic environment with numerous local faults. Modeling fault-to-fault jumps within this region also results in a significant number of ruptures in the system that connects multiple local faults. These ruptures can have significant impacts on seismic performance assessments for spatially distributed infrastructures. Our results show that multi-fault ruptures play a significant role on assessing network performances at the return periods that are crucial to meet seismic resilience criteria.

Presenting Author: Yajie Lee

Authors