Crustal Architecture Across Southern California and Its Implications on San Andreas Fault Development

Abstract

In this study, we perform a 2‐frequency sequential receiver function stacking investigation in Southern California. The resulting Moho depths exhibit similar patterns to previous studies while the crystalline crustal Vp/Vs values show more regional variations. Most Vp/Vs variations can be explained by compositional differences. We observe a dichotomy in Moho depth, Vp/Vs, and crustal strain rates between the Peninsular Ranges and Southern San Andreas Fault system. Comparisons between strain rates, Vp/Vs, and temperature suggest that crustal compositional variations may have played a more critical role in influencing the crustal strain rate variations in the Peninsular Ranges and Southern San Andreas than temperature. The structural and compositional variations provide a new insight into the causes of the migration of the Southern San Andreas Fault system and the formation of the “Big Bend.”

A method for correcting InSAR interferogram errors using GNSS data and the K-means algorithm

“…Regarding the corresponding LOS deformation rate variations across the fault profiles (shown in the right panels of Figs. 8 and 12), the deformation rates of 137A and 144D have significant steps on both sides of the faults, especially at the 1st and 3rd intersection points of the San Andreas fault and the intersection point of the Garlock fault (approximately 5 mm), which is in agreement with the findings of previous studies conducted by other scholars (Dolan et al 2016;Scharer and Yule 2020;Sui et al 2023). In addition, since the experiments in this paper use publicly released interferogram data from scientific research institutions, the cumbersome process of InSAR data processing is avoided, the computational efficiency of acquiring high-precision InSAR deformation time series is improved, and the application difficulty for the GNSS correction of interferogram errors is decreased.…”