Comparing Quasi-Dynamic and Fully Dynamic Earthquake Cycle Simulations on Dip-Slip Faults

Zizhuang Tang, & Benchun Duan

Published September 8, 2024, SCEC Contribution #13959, 2024 SCEC Annual Meeting Poster #151

Quasi-dynamic (QD) earthquake cycle simulations typically use radiation damping (Rice, 1993) to approximate the coseismic rupture process and ignore seismic wave propagation. They are computationally efficient. However, previous studies on strike-slip faults have shown obvious difference in earthquake behaviors from these models, compared with fully dynamic (FD) earthquake cycle simulations that capture spontaneous rupture and seismic wave propagation by solving equations of motion during the coseismic process. How do QD perform on dip-slip faults, comparing with FD? This question has not been addressed in the scientific community.
In this study, we use our code EQdyna to perform FD simulations on dip-slip faults in a 3D medium. We implement radiation damping into the quasi-static part of EQdyna to perform QD simulations on these faults and compare the results. EQdyna is an advanced finite element method (FEM) code designed to simulate earthquake cycles by accurately modeling both seismic and aseismic fault slip behaviors in a 3D medium. Our research aims to explore the differences between QD and FD simulations, focusing on their ability to represent slip velocities, rupture speeds during seismic events, and the interaction with asperity regions. The goal is to assess the applicability of QD simulations on dip-slip faults and understand their potential limitations when compared to FD simulations. This ongoing work will help inform the broader use of QD simulations, particularly where computational efficiency is a priority.

Citation
Tang, Z., & Duan, B. (2024, 09). Comparing Quasi-Dynamic and Fully Dynamic Earthquake Cycle Simulations on Dip-Slip Faults . Poster Presentation at 2024 SCEC Annual Meeting.

Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)