Ground motion characteristics of idealized supershear ruptures: Do they matter for engineering applications?

Mohamed Abdelmeguid, Grigorios Lavrentiadis, Ares J. Rosakis, & Domniki Asimaki

Submitted September 7, 2025, SCEC Contribution #14571, 2025 SCEC Annual Meeting Poster #TBD

We study ground motion characteristics of supershear earthquake ruptures, where the rupture velocity exceeds the shear wave speed. Using dynamic rupture simulations, we compare supershear and subshear ruptures to identify similarities and differences in patterns of ground motion intensity measures. Our findings reveal that supershear ruptures consistently produce stronger ground motion amplitudes than their subshear counterparts across all examined metrics. Peak Ground Velocity (PGV) values for supershear ruptures maintain elevated values beyond 20 km from the fault due to the mildly attenuating nature of Rayleigh Mach Cones. We find that in the near-fault regions ($<$7km), supershear ruptures generate longer shaking durations than subshear ruptures. Furthermore, we find that supershear ruptures generate larger spectral accelerations, particularly in the high-frequency regime (2-3Hz). These findings highlight the importance of considering supershear rupture effects in seismic hazard assessment, and suggest that current building codes may be insufficient for structures exposed to supershear ruptures in the near-field.

Citation
Abdelmeguid, M., Lavrentiadis, G., Rosakis, A. J., & Asimaki, D. (2025, 09). Ground motion characteristics of idealized supershear ruptures: Do they matter for engineering applications?. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Ground Motions (GM)