By: Tran Huynh, Edric Pauk, Scott Marshall, Patricia Persaud
Published June 1, 2025
The SCEC Science Collaboration
The SCEC Science Plan outlines a roadmap for distributing research efforts across southern, central, and northern California to achieve the Center’s science goals as the Statewide California Earthquake Center. SCEC prioritizes investigator-driven, interdisciplinary research, fostering connections with scientific, engineering, and community stakeholders. This collaborative approach sustains earthquake science research, explores new avenues, welcomes new investigators, and provides a global platform for multidisciplinary research, workforce development, and community engagement.
Each year, SCEC solicits projects through a competitive process, attracting hundreds of investigators. In 2024, with funding from NSF, USGS, DOE, and NASA, SCEC awarded over $2.0 million in mini-grants to support 62 research projects, six workshops, and one technical skills training, involving 110 investigators across 39 institutions and over 400 participants. These projects have concluded, and their outcomes are now available in the SCEC awards database. Below, we highlight one area — the Community Earth Models — that showcases how the collective efforts of the SCEC community are more than the sum of their parts.
In response to the 2025 Science Plan announced in October 2024, SCEC received 33% more proposals compared to the previous year, with total funding requests exceeding $3.8 million. Among the 160 investigators, 47 were first-time principal investigators submitting proposals to SCEC. Nearly two-thirds of the proposed projects, spanning from mapping hidden faults to studying the shaking from earthquakes, indicated they will contribute to or use SCEC Community Earth Models.
This year, SCEC will award $1.93 million to support 64 research projects and seven science workshops selected for the 2025 Collaboration Plan. Many investigators across 36 institutions have begun their work. Their preliminary results will be showcased at the 2025 SCEC annual meeting, scheduled for September 7-10.
Community-Built Models for Earthquake Studies
In 2024, SCEC made significant strides in developing Community Earth Models (CEMs) to describe California’s lithosphere and asthenosphere statewide. These models provide an integrated framework to simulate and study earthquake-related phenomena throughout the San Andreas Fault System (SAFS). In March 2024, we co-hosted the “California Community Models for Seismic Hazard Assessments Workshop” with the USGS, CGS, NASA, LLNL, CIG, and other academic partners to foster collaboration and build a strong community around developing and maintaining CEMs for California. The workshop highlighted key scientific and societal use cases and emphasized the importance of making these models publicly accessible and regularly updated through ongoing scientific collaboration. See the workshop report, where we assess the quality and availability of existing models and data for different regions of the SAFS.
Many groups of experts, using diverse methods and data and incorporating input from various user groups, continue to refine and merge existing models to create a more comprehensive representation throughout the entire Pacific-North American Plate boundary system. The new SCEC Community Fault Model CFM 7.0 now covers all of California using uniform guidelines for inventory, fault hierarchy, documentation, and model access. It includes 556 fault objects, with 113 new ones in central and northern California that are currently under evaluation. The SCEC Community Stress Model v2024 also covers the entire land area of California and parts offshore, with the integration of eight new stress orientation models and three new stressing rate models.
The SCEC Community Fault Model v7.0
Presented by Scott Marshall at the 2025 USGS Northern California Earthquake Hazards Workshop
The 2024 SCEC Community Geodetic Model (CGM) workshop aimed to broaden the geographic scope and expertise, particularly early-career researchers, for statewide CGM efforts. Advances for the SCEC CGM include an expanded GNSS time series coverage for all of California and northern Baja California, Mexico and a new method to integrate GNSS and InSAR data to produce a 3D velocity field at the Earth’s surface to study crustal deformation in California and western Nevada from three decades of data. These groups have initiated a “Community Velocity Field Exercise” to collaboratively develop derived velocity and strain rate products for all of California.
The Community Rheology Model (CRM) and Geological Framework Model (GFM) were tested for their relevance to the California lithosphere by comparing their predictions with actual observations. The tests revealed discrepancies, such as unrealistic strain rates and incorrect seismic velocity trends with depth. A community workshop is planned later this year to tackle these issues and to make progress on the SCEC Community Thermal Model.
Use Cases and Required Components of a Statewide Seismic Wavespeed Model
Presented by Artie Rodgers at the 2025 SCEC workshop on Multi-Scale Seismic Velocity Models for the San Andreas Fault System in the Western US
A major goal of SCEC is to develop multi-scale models to capture the complexity of the entire San Andreas Fault System at a wide range of scales. The April 2025 SCEC workshop on “Multi-Scale Seismic Velocity Models for the San Andreas Fault System in the Western US” gathered 80 experts to accelerate the development of multiscale seismic velocity models for accurate ground motion simulations and seismic hazard assessments for engineering applications. Key topics discussed included tomography workflows, strategies for merging high-resolution local and regional models, integrating diverse geophysical data, and developing robust uncertainty quantification methods. During the Spring of 2025, a new CVM Explorer was introduced, providing easy access and visualization of 23 seismic velocity models covering all of California and some parts offshore. While significant progress has been made, challenges remain in integrating new data, improving resolution, merging models, and assessing uncertainties for major sedimentary basins across California, tested for wave propagation simulations.
To make Community Earth Models accessible for research and education, and to enable opportunities for continuous validation against real-world data, SCEC launched in 2024 a dedicated CEM homepage on scec.org. This serves as a one-stop shop for all SCEC CEM products, linking to individual model homepages, web-based explorers, and publicly accessible archives. These pages provide essential documentation for interoperability and reusability, while the web-based explorers enhance accessibility for both new and advanced users. The SCEC community continues to collaborate with partners, including the new Cascadia Region Earthquake Science Center (CRESCENT), to fill in critical data gaps and accelerate the development and refinement of Community Earth Models in overlapping areas of interest such as the Mendocino Triple Junction.
The SCEC Community Earth Models embody decades of collaborative research by hundreds of scientists and developers worldwide. As earthquake science evolves, it increasingly depends on more accessible data and models that capture key Earth parameters. SCEC continues to lead by offering expert-curated models for California with enhanced accessibility, documentation, and spatial coverage. These models will support next-generation simulations and drive progress in earthquake system science.
We encourage you to register your SCEC-funded research in the SCEC publications database and share news about your results and collaborations with the SCEC Science Steering Committee (SSC) to highlight in future communications.
These select publications and presentations showcase recent advances in SCEC Community Earth Model development:
- Plesch, A., Marshall, S. T., Shaw, J. H., Su, M., Maechling, P. J., Huynh, T. T., & Pauk, E. (2024, 09). CFM 7.0: Integration of southern, central, and northern California 3d fault representations into a uniform, statewide Community Fault Model. Poster Presentation at 2024 SCEC Annual Meeting. SCEC Contribution Number 13870
- Becker, T., Schulte-Pelkum, V., & Kilb, D. (2025, 08). Comparative analysis of transform fault evolution from lithospheric seismic anisotropy along the San Andreas system. Oral Presentation at International Association of Geomagnetism and Aeronomy/International Association of Seismology and Physics of the Earth’s Interior Joint Scientific Meeting 2025. SCEC Contribution Number 14177
- Schulte-Pelkum, V., & Kilb, D. (2025, 01). Imaging northern California faults across the brittle- ductile transition using receiver function anisotropy, seismicity, and focal mechanisms. Oral Presentation at Northern California Earthquake Hazards workshop. SCEC Contribution Number 14173
- Kilb, D., Schulte-Pelkum, V., & Becker, T. (2024, 12). Fault fabric as a function of fault maturity and its interaction with preexisting structures: Examples from the San Andreas plate boundary system. Oral Presentation at American Geophysical Union. SCEC Contribution Number 14172
- Schulte-Pelkum, V., Kilb, D., & Becker, T. W. (2024, 09). Fault imaging past the brittle-ductile transition: Relationship between fault fabric and maturity from anisotropic receiver function analysis of the San Andreas plate boundary system. Poster Presentation at 2024 SCEC Annual Meeting. SCEC Contribution Number 13810
