Multi-Scale Seismic Velocity Models for the San Andreas Fault System in the Western US
Date: April 4, 2025 (08:30am – 4:30pm Pacific)
Location: Online via Zoom
Workshop Organizers: Patricia Persaud (U Arizona), Kim Olsen (SDSU), Artie Rodgers (LLNL), Phil Maechling (USC), Yehuda Ben-Zion (USC)
SCEC is hosting a workshop to accelerate the development and improvement of multiscale seismic velocity models that are essential for accurate ground motion simulations and seismic hazard assessments in California and beyond. While significant progress has been made, challenges remain in integrating new data, improving resolution, merging models, and assessing uncertainties. This workshop will focus on planning a coordinated research approach to develop multiscale P- and S-wave velocity models for the San Andreas fault system in the Western US, targeting simulations up to 5-10 Hz, a frequency range critical for engineering applications. Participants will discuss tomography workflows, strategies for merging high-resolution local models and regional models, integrating diverse geophysical data, and developing robust uncertainty quantification methods. The workshop will also address the development of essential IT tools for model management and access, ensuring practical implementation of workshop recommendations. Join us to contribute to the next generation of SCEC CVMs and enhance our understanding of crustal structures and seismic hazards.
Time | Agenda Item | Speaker | |
---|---|---|---|
08:30 - 08:40 | Welcome and Overview of Workshop Objectives | Yehuda Ben-Zion | |
Session 1: Current Seismic Velocity Models for the SAFS in the Western US Moderators Rob Graves and Patricia Persaud | |||
08:40 - 09:00 | Use Cases for Velocity Models & Required components of Statewide Velocity Model | Artie Rodgers | |
09:00 - 09:15 | Overview from SCEC March '24 Workshop report | Brad Aagaard | |
Resolution of Current Velocity Models | |||
09:15 - 09:30 | Regional Tomographic models | Cliff Thurber | |
09:30 - 09:45 | Geology-based models | Oliver Boyd | |
09:45 - 10:00 | Basin-scale models | John Shaw | |
10:00 - 10:15 | Near surface | Domniki Asimaki | |
10:15 - 10:30 | Discussion: needs and opportunities | All | |
10:30 - 10:50 | Break | ||
Observational Data Gaps | |||
10:50 - 11:05 | Geographic areas with critical data needs | Albert Kottke | |
11:05 - 11:20 | Seismic attenuation | Chiara Nardoni | |
11:20 - 12:00 | Discussion: needs and opportunities | All | |
12:00 - 13:00 | Break | ||
Session 2: Methods to Combine and Evaluate Velocity Models Moderators Kim Olsen and Cliff Thurber | |||
13:00 - 13:15 | Fusion methods - embedding and smoothing | Alan Juarez-Zuniga | |
13:15 - 13:30 | Fusion methods - machine learning | Te-Yang Yeh | |
13:30 - 13:50 | Estimating epistemic uncertainty in ground motions from 3-D simulations | Norman Abrahamson | |
13:50 - 14:30 | Discussion: needs and opportunities | All | |
14:30 - 14:50 | Break | ||
Session 3: Tools for Using Models Moderators Patricia Persaud and Artie Rodgers | |||
14:50 - 15:10 | Practical aspects of seismic velocity model tools | Phil Maechling | |
15:10 - 16:00 | Discussion: needs and opportunities | All | |
16:00 - 16:30 | Wrap-up | ||
Workshop Adjourns |
March 4-5, 2024
September 1, 2020
September 7, 2019
October 2, 2018
CEMs are collaborative platforms featuring community-contributed data, models, and tools for earthquake system analysis. They enable 3D visualization, data exploration, sharing, and integrated modeling.
Unified Community Velocity Model (UCVM)
seismic velocities for several California regions
Community Geodetic Model (CGM) Explorer
Earth surface displacement from GNSS and InSAR
Community Fault Model (CFM) Explorer
3D geometric representations of faults in California
Community Stress Model (CSM) Explorer
suite of models of stress and stressing rate
Community Rheology Model (CRM) Viewer
3D ductile rheology of lithosphere in S. California
Geologic Slip Rate Database (GSRD)
geologic slip rates for CA, NV, and northern Mexico
Precariously Balanced Rock (PBR) Database
field-derived data for PBRs in California
The Statewide California Earthquake Center (SCEC) fosters a diverse and inclusive community where everyone feels safe, productive, and welcome. We expect all participants in SCEC-supported events to uphold this commitment by adhering to the SCEC Activities Code of Conduct.
The SCEC Annual Meeting brings together 400-500 participants worldwide to share breakthroughs, assess progress, and chart a collaborative path for earthquake science. All of the Center activities are presented, analyzed, and woven into a set of priorities for SCEC to pursue in the future.
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