SCEC Award Number 15008 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Improvement of Earthquake Simulators: Focus on On-Fault Aftershocks and Forecasting
Name Organization
John Rundle University of California, Davis
Other Participants 1 Graduate Student Researcher, TBD
SCEC Priorities 4e, 2e, 1e SCEC Groups Simulators, CS, SDOT
Report Due Date 03/15/2016 Date Report Submitted 03/02/2016
Project Abstract
We addressed the problem of verifying the self-­‐consistency of earthquake simulators with the data from which their parameters are drawn. Earthquake simulators are a class of computational simulations which attempt to mirror the topological complexity of fault systems on which earthquakes occur. In addition, the physics of friction and elastic interactions between fault elements can be included in these simulations. Verification of simulations against current observed earthquake seismicity is necessary. We present two methods for addressing this discrepancy: a simplistic approach whereby observed earthquakes are shifted to the nearest fault element and a variation of the Epidemic-­‐type aftershock (ETAS) model, which distributes the simulator catalog seismicity over the entire test region. To test these methods, a Receiver Operating Characteristic (ROC) plot was produced by comparing the rate maps f o r t h e f o u r simulators tested in the Tullis et al. testing project to observed m > 6.0 earthquakes since 1980. We found that the nearest-­‐neighbor mapping produced poor forecasts, while the modified ETAS method produced rate maps that agreed with observations.
Intellectual Merit none submitted
Broader Impacts none submitted
Exemplary Figure Figure 2: Time-independent log rate maps for AllCal (upper left), Virtual Califiornia (upper right, ViscoSim (lower left), and RSQSim (lower right. Maps produced by applying a modified ETAS field for each simulated event. Color scale is different for each to show detail.