Exciting news! We're transitioning to the Statewide California Earthquake Center. Our new website is under construction, but we'll continue using this website for SCEC business in the meantime. We're also archiving the Southern Center site to preserve its rich history. A new and improved platform is coming soon!

Poster #135, Fault and Rupture Mechanics (FARM)

Numerical modelling of rupture dynamics constrained by past seismicity for ground motion prediction

Elif Oral, Jean-Paul Ampuero, Javier Ruiz, & Domniki Asimaki
Poster Image: 

Poster Presentation

2021 SCEC Annual Meeting, Poster #135, SCEC Contribution #11235 VIEW PDF
Predicting ground motion by physics-based modelling, particularly at magnitudes and distances that lack empirical data, has been an attractive avenue for seismic hazard assessment studies. In the proximity of a fault, both source- and site-related complexities control the final ground motion; understanding the impact of these complexities on ground motion, therefore, matter to reason and constrain the associated variability of ground motion. Initial stress heterogeneity is one of the acknowledged source-related complexities to account for, and we hypothesize that it results from the superposition of residual stresses left by past seismicity. Here we develop a new method to generate initial s...tress heterogeneity that is governed by the regional statistics of past seismicity, including the Gutenberg-Richter frequency-magnitude distribution and the hypocentral depth distribution. Our modelling conforms with fracture mechanics theory and applies scale-dependent fracture energy, and we calibrate rupture models to satisfy empirical earthquake scaling laws and ground motion prediction equations. We validated our method through Mw 7 earthquake models suitable for California and investigated the impact of background seismicity on rupture dynamics and near-field ground motion. Our results, with 3 Hz resolution, suggest a notable spatial variation of ground motion metrics close to faults due to background stress heterogeneity. The outputs of our study promises to disentangle source and site effects on near-field ground motion with the use of regional statistical data.