Stranger Quakes: Capturing the Complexity of the Earth in Seismic Hazard Models
Morgan Page, USGS - ESC
Wednesday, February 27, 2019 at 10:30 AM
- Building 3, Rambo Auditorium
Seismic hazard models in California have evolved from simple segmented prescriptive models to much more complex representations of multi-fault and multi-segment earthquakes in an interconnected fault network. During the development of the 3rd Uniform California Earthquake Rupture Forecast (UCERF3), the prevalence of multi-fault ruptures in the modeling was controversial. Yet recent earthquakes, for example, the 2016 M7.8 Kaikoura earthquake – have validated this approach. If anything, connectivity in the UCERF3 may be underestimated, although spatio-temporal clustering in the model may mitigate some modeling simplifications.
Future iterations of hazard models should continue to improve the modeling of the connectivity of the fault system and include the largest, strangest events. The goal should not be to predict the exact rupture process likely to happen in a future Kaikoura-like rupture, but to capture enough connectivity so that the hazard estimation is accurate.