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!

Computing Elastic‐Rebound‐Motivated Earthquake Probabilities in Unsegmented Fault Models: A New Methodology Supported by Physics‐Based Simulators

Edward H. Field

Published March 31, 2015, SCEC Contribution #2065

A methodology is presented for computing elastic-rebound-based probabilities in an un-segmented fault or fault system, which involves computing along-fault averages of renewal-model parameters. The approach is less biased and more self-consistent than a logical extension of that applied most recently for multi-segment ruptures in California. It also enables the application of magnitude-dependent aperiodicity values, which the previous approach does not. Monte Carlo simulations are used to analyze long-term system behavior, which is generally found to be consistent with that of physics-based earthquake simulators. Results cast doubt that recurrence-interval distributions at points on faults look anything like traditionally applied renewal models, a fact that should be considered when interpreting paleoseismic data. We avoid such assumptions by changing the “probability of what” question (from offset at a point to the occurrence of a rupture, assuming it is the next event to occur). The new methodology is simple, although not perfect in terms of recovering long-term rates in Monte Carlo simulations. It represents a reasonable, improved way to represent first-order elastic-rebound predictability, assuming it is there in the first place, and for a system that clearly exhibits other un-modeled complexities like aftershock triggering.

Citation
Field, E. H. (2015). Computing Elastic‐Rebound‐Motivated Earthquake Probabilities in Unsegmented Fault Models: A New Methodology Supported by Physics‐Based Simulators. Bulletin of the Seismological Society of America, 105(2A), 544-559. doi: 10.1785/0120140094.