SCEC Award Number 23167 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Flexible and Scalable Earthquake Forecasting
Investigator(s)
Name Organization
Emily Brodsky University of California, Santa Cruz
Other Participants Gaspard Farge (Postdocs)
SCEC Priorities 5c, 5d, 5e SCEC Groups EFP, Seismology, FARM
Report Due Date 03/15/2024 Date Report Submitted 11/08/2024
Project Abstract
 Establishing the extent of earthquake predictability is a central goal of SCEC. The key goal of this work was to apply forecasting methods to Parkfield, where slow slip and low frequency earthquakes are thought to interacts. As a few step, investigated the interactions between the existing low-frequency earthquake catalog and the ordinary earthquakes. We found low-frequency earthquakes do not appear to trigger earthquakes in Parkfield, contrary to common wisdom on this problem. However, earthquakes do trigger low-frequency earthquakes, and by implication, perhaps slow slip. This work stimulated a new line of thinking into tremor synchronization and its relationship to regional seismicity rates that has predictive value as discussed at the 2024 CSEP workshop.
Intellectual Merit A basic tenet of 21st century seismology is that slow slip earthquakes should trigger ordinary earthquakes. This work showed that this is not the case in Parkfield, California. Low-frequency earthquakes have no predictive value here for ordinary earthquakes.
Broader Impacts This work directly addresses the societally significant question of earthquake predictability by delineating what is useful, or not, for improving predictions at this site. In addition, the work provided support for an early career scientist, Dr. Gaspard Farge, who was a postdoc under this grant. This grant also supported his professional development by allowing him to participate in the SCEC annual meeting.
Exemplary Figure
Figure 1. An evaluation of earthquakes potentially triggering low-frequency earthquakes at Parkfield. The data show no significant correlation, which is counter to the accepted thinking on this problem that low-frequency earthquakes are symptomatic of slow slip that triggers earthquakes.
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