SCEC Award Number 25295 View PDF
Proposal Category Individual Research Project (Single Investigator / Institution)
Proposal Title Building a statewide creep rate model from repeating earthquake sequences and geodetic data
Investigator(s)
Name Organization
Gareth Funning University of California, Riverside
SCEC Milestones A3-5 SCEC Groups Seismology, Geodesy, SDOT
Report Due Date 03/15/2026 Date Report Submitted 05/08/2026
Project Abstract
 The goal of the project was to work towards building a statewide creep rate model using slip rate estimates derived from geodetic data and repeating earthquakes. This work primarily involved the detection, characterization and validation of repeating earthquake families across the San Andreas Fault System, which can ultimately be combined with geodetic data to estimate the creep rate distributions on faults of interest. The combination of repeating earthquake information with geodetic data will improve our constraints on fault creep at all depths compared with either data type alone. In the project to date, we have analyzed over 7 million earthquake waveforms across the state of California, both north and south, and identified over 12,000 repeating earthquake families. Faults in southern California show very few repeating earthquakes, compared to the faults of the San Andreas system in central and northern California, likely reflecting a fundamental difference in fault zone properties and materials between the two regions. Results from this work will provide insight into how creep at depth is distributed across California faults, an important constraint on seismic potential and seismic hazard. The project was led by UC Riverside graduate student Norma Contreras, supervised by PI Gareth Funning.
SCEC Community Models Used Community Fault Model (CFM)
Usage Description We use the CFM to associate repeating earthquakes with structures.
Intellectual Merit The goal of the project was to work towards building a statewide creep rate model using slip rate estimates derived from geodetic data and repeating earthquakes. In the project to date, we have analyzed over 7 million earthquake waveforms across the state of California, both north and south, and identified over 12,000 repeating earthquake families. Faults in southern California show very few repeating earthquakes, compared to the faults of the San Andreas system in central and northern California, likely reflecting a fundamental difference in fault zone properties and materials between the two regions.
Broader Impacts The project supported the ongoing training of a graduate student. A repeating catalog for California will contribute to future versions of the National Seismic Hazard Model, which is widely used to inform seismic mitigation efforts.
Project Participants Gareth Funning, PI
Norma Contreras, Graduate Student
Exemplary Figure Figure 5: RE sequences for northern California (left) and southern California (right). Sequences are color-coded according to their duration (time elapsed between the first and last event in a sequence).
Linked Publications

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