Impact of 2019 Mw 5.8 Marmara Sea Earthquake on the seismic cycle of locked North Anatolian Fault segment

Sopacı E., ÖZACAR A. A.

Tectonophysics, vol.859, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 859
  • Publication Date: 2023
  • Doi Number: 10.1016/j.tecto.2023.229888
  • Journal Name: Tectonophysics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), Artic & Antarctic Regions, Communication Abstracts, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: Earthquake triggering, Failure time advance, Full-dynamic simulation, Main Marmara Fault, Rate-and state friction, Spring-slider
  • Middle East Technical University Affiliated: Yes


The Mw5.8 earthquake in the Marmara Sea west of the locked segment of the North Anatolian Fault sparked a debate on whether this event may trigger or advance the expected large (Mw>7) earthquake close to Istanbul in time. Its potential effect on the major earthquake cycle is analyzed using rate-and-state friction (RSF) dependent spring-slider models by considering miscellaneous views of friction and different simulation strategies. Dynamic and static effects are simulated using recorded seismic waveforms and computed static stress change. Results indicated that this moderate earthquake cannot produce instant triggering on the locked fault segment but can advance the failure time noticeably. Simulations display no sensitivity to the inertial damping term; thus, quasi-dynamic and full-dynamic approaches agree. On the other hand, strong brittle-ductile coupling, smaller asperity size, and reduced clamping due to normal stress variations shorten the seismic cycle and increase the induced failure time advances. If failure is far in time (>5% of the recurrence time), the long-term effect on the seismic cycle is static and especially exceeds Coulomb failure predictions considerably when the system is strongly coupled. If fault failure is close, which is likely in this case, dynamic effects lead to responses that differ among state laws. The Ruina (slip) law which has a weakening rate more consistent with the laboratory velocity step tests, shows the highest failure time advance (≈ 1% of the recurrence interval), implying that the failure time is more imminent than before for the locked fault segment beneath the Marmara Sea.