SCEC Award Number 11029 View PDF
Proposal Category Workshop Proposal
Proposal Title Workshop on Comparison and Validation of Earthquake Simulators
Name Organization
Terry Tullis Brown University
Other Participants
SCEC Priorities A6, A10, A9 SCEC Groups EFP, FARM, Seismology
Report Due Date 02/29/2012 Date Report Submitted N/A
Project Abstract
This was a workshop again to bring together those in the SCEC community who are working on various types of computer simulators of earthquake sequences. The principal purposes of the workshop were 1) to compare our first results for an all-California fault model and 2) to prepare for a joint workshop with the WGCEP in June, 2011. The purpose of that joint June workshop is to consider the value that Earthquake Simulators might play in developing UCERF3 and subsequent versions of UCERF. The SCEC workshop was held at the end of an ACES meeting, the last day of which had a focus on earthquake simulations. Thus that last day involved more general presentations on our earthquake simulators and was attended by many of the ACES participants. Then, after that last day of the ACES workshop, a subsequent day was specifically devoted to considering how the results of our different simulators compare and to prepare for the joint workshop in June.
Intellectual Merit Clearly one of the biggest tasks facing the earthquake simulator community is to determine how meaningful are their simulations. During our 2011 workshop it became evident that two of the simulators (ALLCAL and RSQSim) behave quite similarly and are similar to observations, whereas two others (VIRTCAL and ViscoSim) behave somewhat differently, but in opposite ways. We were able to identify likely reasons for these differences and this led to ongoing work to explore what modifications might be appropriate to bring them into better agreement with observations. The VIRTCAL simulator shows more characteristic earthquakes, with more large events and fewer smaller events as compared to the other simulators. This is a result of setting a parameter that encourages ruptures to propagate once started in a way that encourages rupture propagation more than do the other simulators. In contrast, ViscoSim shows fewer large events and more frequent smaller ones, a result of it’s not having a parameter that encourages rupture propagation.
Broader Impacts This workshop assists in developing an understanding of possible earthquake histories that we anticipate will be useful for developing physics-based understanding of the probability of occurrence of earthquakes, both time-independent and time-dependent. This can help develop better versions of the UCERF which is required by statute to be used in developing earthquake insurance rates by CEA.
Exemplary Figure No figures - this is only a workshop report. Figures are in the reports for the EQ Simulator Comparison grants.