SCEC Award Number 22092 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Testing earthquake recurrence models with paleoseismic time series
Investigator(s)
Name Organization
Michael Oskin University of California, Davis Bruce Shaw Columbia University
Other Participants Kevin Milner, Tom Rockwell
SCEC Priorities 5a, 5b, 5c SCEC Groups EFP, Geology, SAFS
Report Due Date 03/15/2023 Date Report Submitted 03/14/2024
Project Abstract
 This project aimed to test earthquake recurrence interval models against data, with
the aid of earthquake simulators. Comparison of recurrence intervals in trenches against
earthquake simulator data was used to better understand the data and the model. In initial
comparisons, one difference was that many smaller intervals were seen in the data compared
to the model. One contribution of CPI Shaw was to point out that uncertainties in the
trench dating needed to be accounted for in the comparison.
Intellectual Merit Earthquake simulators have the potential to contribute to our understanding of earthquake hazard and earthquake physics in a number of different ways. One way is in directly estimating earthquake rupture forecasts, which, when combined with ground motion models, give hazard estimates which compare very well with traditional statistical model estimates [Shaw et al., 2018]. This ability to replicate statistically based seismic hazard estimates by a physics-based model cross-validates standard methods and provides a new alternative approach needing fewer inputs and assumptions for estimating hazard. A second way is to use the models to help develop and constrain assumptions in the statistical models. Improving rupture sets using the simulators contributed in this way [Milner, Shaw, and Field, 2022]. A third way is to use the simulators as source models for ground motion studies [Milner, Shaw, et al., 2021]. All of these approaches help advance our understanding of hazard, and the potential underlying earthquake physics. This project fit into the goal of working to compare against a vast variety of observational datasets.
Broader Impacts The project contributes to improving seismic hazard estimates, which helps society better mitigate the hazards.
Exemplary Figure Figure 1: Coefficient of variation in timing between events. (a) Map view of COV. Fault ends
tend to have higher values. (b) COV as a function of fault slip rate. Note the fastest moving faults
appear to be more regular than slower ones.