Characterizing Deep, Shallow, and Surface Fault Zone Deformation of the 2021 Mw 7.4 Maduo, China, Earthquake

Abstract

Abstract Long-term fault growth involves the evolution of fault zone architecture, structural maturity, and physical properties. Accurate characterization of these features is essential for improving the understanding of fault mechanics and earthquake hazards. Here, we integrate relocated aftershocks (Wang, Fang, et al., 2021), optical satellite imagery (Li et al., 2023), and field measurements (Yuan et al., 2022) to study the aftershock zone thickness and decay, coseismic surface strain, off-fault deformation, and the buried shallow fault slip of the 2021 Mw 7.4 Maduo earthquake, which occurred on an immature fault based on the total cumulative displacement of 4–5 km. We comprehensively characterize the deep, shallow, and surface fault zone deformation and link the observed variations of kinematic features to the structural maturity of the fault zone structure. Our study provides a macroscopic description of the fault zone deformation and their patterns across earthquake ruptures for the Maduo earthquake, and may have broader implications for the continental immature faults.