The Community Stress Drop Validation Study

Rachel E. Abercrombie, Annemarie S. Baltay, Dino Bindi, Oliver S. Boyd, Xiaowei Chen, Elizabeth S. Cochran, Hao Guo, Rebecca M. Harrington, Evan T. Hirakawa, Yihe Huang, Chen Ji, Zhe Jia, Olga-Joan Ktenidou, Shiying Nie, Adrien Oth, Grace A. Parker, Camilo Ignacio Pinilla Ramos, Colin N. Pennington, Peter M. Shearer, Minkyung Son, Mariano Supino, Taka'aki Taira, Clifford H. Thurber, Elisa Tinti, Daniel T. Trugman, & Hongfeng Yang

Submitted August 30, 2026, SCEC Contribution #15600, 2026 SCEC Annual Meeting Poster #TBD

The SCEC/USGS Community Stress Drop Validation Study aims to reduce uncertainties in estimated spectral stress drop and related source parameters, strengthening their use in empirical ground motion models and earthquake source simulations. This newly supported SCEC Technical Activity Group has already built a global research community focused on understanding the physical and methodological causes of variability in earthquake stress drop and source parameter estimates. In Phase I, we demonstrated and quantified the challenges with existing methods of characterizing small earthquake source parameters in a community analysis of the 2019 Ridgecrest earthquake sequence. The focus of the new TAG is to understand the causes of the discrepancies and uncertainties, develop and test improved approaches to characterize earthquake source parameters, and improve ground motion modeling. We will benchmark emerging spectral and time-domain methods using a new Bay Area dataset, synthetic data, and continued analysis of the 2019 Ridgecrest sequence. We will also focus on seismic moments and site amplification and attenuation effects, which strongly tradeoff with source parameters such as fitted spectral corner frequency. We will continue to hold regular workshops, and more informal online updates aimed at both seeking input from related communities who depend on measurements of source and site effects. We welcome new participants at any time, to perform analysis, lead subgroups, contribute to discussion or simply learn more about stress drop.

Key Words
earthquake, stress drop, scaling, source physics

Citation
Abercrombie, R. E., Baltay, A. S., Bindi, D., Boyd, O. S., Chen, X., Cochran, E. S., Guo, H., Harrington, R. M., Hirakawa, E. T., Huang, Y., Ji, C., Jia, Z., Ktenidou, O., Nie, S., Oth, A., Parker, G. A., Pinilla Ramos, C., Pennington, C. N., Shearer, P. M., Son, M., Supino, M., Taira, T., Thurber, C. H., Tinti, E., Trugman, D. T., & Yang, H. (2026, 08). The Community Stress Drop Validation Study. Poster Presentation at 2026 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology