Sub- and super-shear ruptures during the 2023 Mw 7.8 and Mw 7.6 earthquake doublet in SE Türkiye

Melgar D., Taymaz T., Ganas A., Crowell B., Öcalan T., Kahraman M., ...More

Seismica, vol.2, no.3, pp.1-10, 2023 (Peer-Reviewed Journal)

  • Publication Type: Article / Article
  • Volume: 2 Issue: 3
  • Publication Date: 2023
  • Doi Number: 10.26443/seismica.v2i3.387
  • Journal Name: Seismica
  • Journal Indexes: Other Indexes
  • Page Numbers: pp.1-10
  • Yıldız Technical University Affiliated: Yes


An earthquake doublet (Mw 7.8 and M7.6) occurred on the East Anatolian Fault Zone (EAFZ) on February 6th, 2023. The events produced significant ground motions and caused major impacts to life and infrastructure throughout SE Türkiye and NW Syria. Here we show the results of earthquake relocations of the first 11 days of aftershocks and rupture models for both events inferred from the kinematic inversion of HR-GNSS and strong motion data considering a multi-fault, 3D geometry. We find that the first event nucleated on a previously unmapped fault before transitioning to the East Anatolian Fault (EAF) rupturing for ~350 km and that the second event ruptured the Sürgü fault for ~160 km. Maximum rupture speeds were estimated to be 3.2 km/s for the Mw 7.8 event. For the Mw 7.6 earthquake, we find super-shear rupture at 4.8 km/s westward but sub-shear eastward rupture at 2.8 km/s. Peak slip for both events were as large as ~8m and ~6m, respectively.