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Finite-source Attributes of M4 to 5.5 Ridgecrest, California Earthquakes

Wenyuan Fan, Haoran Meng, Daniel T. Trugman, Jeff J. McGuire, & Elizabeth S. Cochran

In Preparation December 7, 2022, SCEC Contribution #12876

Resolving earthquake rupture processes is essential for understanding earthquake physics and determining seismic hazards. However, it remains challenging to solve the finite-source attributes of moderate and small earthquakes directly; rupture processes of such events are traditionally resolved using spectral methods in the frequency domain. In this study, we apply a time-domain approach that makes minimal assumptions to estimate the second-degree seismic moments of M 4 to 5.5 earthquakes from the 2019 Ridgecrest, California sequence. The second moments can characterize earthquake finite-source attributes, including the rupture length, width, duration, velocity, and directivity. The Ridgecrest high-quality dataset offers an opportunity to quantitatively evaluate the uncertainties of the finite-source models. We aim to examine the impacts on the obtained source parameters from the model assumptions and data imperfections by performing a suite of statistical evaluations and estimating the extreme models. We will further compute the earthquake static stress-drop with the kinematic attributes and compare the results with frequency-domain estimates obtained using spectral analysis to better understand the strengths and limitations of different approaches to source characterization.

Fan, W., Meng, H., Trugman, D. T., McGuire, J. J., & Cochran, E. S. (2022, 12). Finite-source Attributes of M4 to 5.5 Ridgecrest, California Earthquakes. Poster Presentation at AGU Fall Meeting 2022.