CyberShake hazard with the MUSCAL velocity model

Scott Callaghan, Xiaofeng Meng, Robert W. Graves, Kim B. Olsen, Mei-Hui Su, Fabio Silva, Akash Bhatthal, Morgan P. Moschetti, Albert R. Kottke, Kevin R. Milner, Te-Yang Yeh, Yehuda Ben-Zion, & Ahmed E. Elbanna

Submitted August 30, 2026, SCEC Contribution #15464, 2026 SCEC Annual Meeting Poster #TBD

The SCEC CyberShake platform implements physics-based probabilistic seismic hazard analysis in California. CyberShake performs 3D wave propagation simulations using AWP-ODC through velocity meshes generated with UCVM to generate strain Green tensors (SGTs) at locations of interest. The SGTs are then convolved with individual slip time histories generated with the Graves-Pitarka kinematic rupture generator for hundreds of thousands of events of interest, generating three-component seismograms. The seismograms are post-processed to yield intensity measures and hazard data products such as curves and regional maps, and these data products are made available to the community.

We will present new CyberShake hazard runs using the MUSCAL 3D (Yeh et al., 2026) velocity model, including the extended MUSCAL model delivered through UCVM for portions of simulation volumes outside of California and Nevada. We will present comparisons between CyberShake hazard calculated using MUSCAL and the two previous CyberShake studies, 24.8 (northern California) and 22.12 (southern California), which used different velocity models. We find moderate, site-specific changes in hazard with the updated model. These preliminary results lay the groundwork for the next large CyberShake study with the MUSCAL model planned for 2027.

Additionally, we now calculate an additional CyberShake data product: smoothed effective amplitude spectrum (smoothed EAS), generated using the SCEC GMSV Toolkit. The addition of smoothed EAS to the CyberShake suite of data products will facilitate CyberShake simulation usage by ground motion model developers and the engineering community.

Key Words
seismic hazard analysis, high performance computing, computational seismology

Citation
Callaghan, S., Meng, X., Graves, R. W., Olsen, K. B., Su, M., Silva, F., Bhatthal, A., Moschetti, M. P., Kottke, A. R., Milner, K. R., Yeh, T., Ben-Zion, Y., & Elbanna, A. E. (2026, 08). CyberShake hazard with the MUSCAL velocity model. Poster Presentation at 2026 SCEC Annual Meeting.

Related Projects & Working Groups
Ground Motions (GM)