Finite-source attributes of M 4 to 5.5 Ridgecrest, California earthquakes

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

Submitted September 11, 2022, SCEC Contribution #12317, 2022 SCEC Annual Meeting Poster #045

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 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 compute and estimate of the earthquake static stress drop directly from the kinematic attributes and compare the results with frequency-domain estimates obtained using spectral analysis from a few prior studies to better understand the strengths and limitations of different approaches to source characterization.

Fan, W., Meng, H., Trugman, D., McGuire, J. J., & Cochran, E. S. (2022, 09). Finite-source attributes of M 4 to 5.5 Ridgecrest, California earthquakes. Poster Presentation at 2022 SCEC Annual Meeting.

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