Abstract
AbstractFew studies have focused on the supershear transition mechanism induced by fault step overs, although seismic observations suggest that rupture speed transitions occur at geometrical complexities on faults. Based on dynamic rupture simulations on fault systems with step overs in a 3‐D full space where the initial stresses preclude a supershear transition on a single buried fault according to the Burridge‐Andrews mechanism, we show that rupture speeds can transit from subshear on the primary fault to supershear on the secondary fault. The low normal stress zone and the high shear stress zone beyond the fault step, which radiate from the end of the primary fault if its rupture arrest is sudden, determine the supershear rupture occurrence on the secondary fault. However, a low shear stress zone traveling at the shear wave speed is also radiated, making the rupture speed return to subshear in most cases. Sustained supershear ruptures are also possible on compressional step overs under certain conditions. Self‐arresting ruptures are observed in the overlap area on the secondary fault. In a half‐space model where supershear rupture is induced by the free surface on the primary fault, the rupture speed on the secondary fault rapidly transits to subshear near the fault step if its width exceeds a critical value.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.