Unraveling Supershear Dynamics of the 1995 Mw 7.2 Multi-segment Nuweiba Earthquake in the Gulf of Aqaba
Description:
The Dead Sea Transform Fault in the Gulf of Aqaba (GoA) functions as an ~180 km long left-lateral strike-slip plate boundary that separates the Arabian plate from the Sinai micro-plate. The GoA is the seismically most active region of the Red Sea and has hosted several large historic earthquakes and thus poses a high seismic hazard to coastal communities. The rapid development of the NEOM project near the GoA highlights the need for enhanced seismic hazard assessment (SHA), however, the offshore nature of the fault system and limited data complicate SHA efforts. Studying past earthquakes provides valuable insights into stress loading, failure mechanisms, and the likelihood for cascading rupture on complex multi-segment fault systems. Such information is critical for accurate seismic hazard assessment in the region.
In this study, we use back-projection and dynamic simulations to analyze the 1995 Mw 7.2 Nuweiba earthquake, the largest instrumentally recorded event in the GoA and along the entire Dead Sea Fault. Our findings reveal a multi-segment cascading rupture on strike-slip and step-over normal fault segments. Our simulations indicate supershear rupture on the optimally pre-stressed Aragonese fault, in agreement with the back-projection observations and surface-wave analysis of Rayleigh waves. Supershear rupture significantly amplifies expected shaking, and hence consequences for coastal communities of this narrow gulf region, with energy radiation more concentrated within the Mach cone causing intensified and prolonged ground motions. The 1995 event only partially ruptured the GoA fault system, notably increasing Coulomb failure stress on the unbroken southern Arnona Fault, which has likely remained silent since 1588. This stress loading could accelerate a future rupture on this vulnerable segment, requiring close monitoring and heightened preparedness for a potential large earthquake in the region.
Session: Numerical Modeling in Seismology: Theory, Algorithms and Applications [Poster]
Type: Poster
Date: 4/17/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Paul
Student Presenter: No
Invited Presentation:
Poster Number: 124
Authors
Bo Li Corresponding Author bo.li.3@kaust.edu.sa King Abdullah University of Science and Technology |
Paul Martin Mai Presenting Author martin.mai@kaust.edu.sa King Abdullah University of Science and Technology |
Thomas Ulrich ulrich@geophysik.uni-muenchen.de Ludwig Maximilian University of Munich |
Suhendi Cahli cahli.suhendi@kaust.edu.sa King Abdullah University of Science and Technology |
Alice-Agnes Gabriel algabriel@ucsd.edu University of California, San Diego |
Yann Klinger klinger@ipgp.fr Paris Institute of Earth Physics |
Sigurjon Jónsson sigurjon.jonsson@kaust.edu.sa King Abdullah University of Science and Technology |
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Unraveling Supershear Dynamics of the 1995 Mw 7.2 Multi-segment Nuweiba Earthquake in the Gulf of Aqaba
Session
Numerical Modeling in Seismology: Theory, Algorithms, and Applications