2025 SCEC CVM Workshop

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)

Overview

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.

April 4, 2025

TimeAgenda ItemSpeaker
08:30 - 08:40Welcome and Overview of Workshop ObjectivesYehuda Ben-Zion

Session 1: Current Seismic Velocity Models for the SAFS in the Western US

Moderators Rob Graves and Patricia Persaud

08:40 - 09:00Use Cases for Velocity Models & Required components of Statewide Velocity ModelArtie Rodgers
09:00 - 09:15Overview from SCEC March '24 Workshop reportBrad Aagaard
Resolution of Current Velocity Models
09:15 - 09:30Regional Tomographic models Cliff Thurber
09:30 - 09:45Geology-based models Oliver Boyd
09:45 - 10:00Basin-scale modelsJohn Shaw
10:00 - 10:15Near surfaceDomniki Asimaki
10:15 - 10:30Discussion: needs and opportunitiesAll
10:30 - 10:50Break
Observational Data Gaps
10:50 - 11:05Geographic areas with critical data needsAlbert Kottke
11:05 - 11:20Seismic attenuationChiara Nardoni
11:20 - 12:00Discussion: needs and opportunitiesAll
12:00 - 13:00Break

Session 2: Methods to Combine and Evaluate Velocity Models

Moderators Kim Olsen and Cliff Thurber

13:00 - 13:15Fusion methods - embedding and smoothingAlan Juarez-Zuniga
13:15 - 13:30Fusion methods - machine learningTe-Yang Yeh
13:30 - 13:50Estimating epistemic uncertainty in ground motions from 3-D simulationsNorman Abrahamson
13:50 - 14:30Discussion: needs and opportunitiesAll
14:30 - 14:50Break

Session 3: Tools for Using Models

Moderators Patricia Persaud and Artie Rodgers

14:50 - 15:10Practical aspects of seismic velocity model toolsPhil Maechling
15:10 - 16:00Discussion: needs and opportunitiesAll
16:00 - 16:30Wrap-up
Workshop Adjourns

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