SPEAKER: Prof. Roby Douilly (UC Riverside)
DATE: 4:00pm, Friday, April 9th, 2021
TITLE: Crustal Deformation Revealed by Complex Rupture Modeling and Seismic Observations
ABSTRACT:
In my Observational and Computational lab, we use seismic source imaging technique to derive crustal properties and we also use dynamic rupture simulation to investigate the effects of complex fault systems on rupture path during an earthquake. In this talk, I will discuss a recent and ongoing studies on dynamic models of earthquake rupture in CA and seismic imaging in Nepal, with a focus on crustal faulting.
In the case study of the rupture modeling in the eastern San Gorgonio Pass region in CA, we examined the effect of different assumptions about fault geometry and initial stress pattern on the dynamic rupture process to test multiple rupture scenarios. We find that a rupture on the Coachella segment is more likely to branch to the Mission Creek rather than to the Banning fault strand.
In the observational study, we used arrival time data from local aftershocks occurring between June 2015 and April 2016 following the M7.8 Gorkha earthquake to determine a 3D Vp velocity structure and hypocenter location in the upper crust of the Main Himalayan Thrust (MHT). Results from the tomographic images show two parallel sub-horizontal low velocity anomalies along profiles perpendicular to the MHT and the velocity contrast is in agreement with surface geological studies.