ANALYSIS OF COULOMB STRESS TRANSFER AND EARTHQUAKE HAZARD IN THE ÇALDIRAN FAULT ZONE AND ITS ADJACENT REGION


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Alkan H., Öztürk S., Akkaya İ.

Mühendislik Bilimleri ve Tasarım Dergisi, vol.11, no.2, pp.519-534, 2023 (Peer-Reviewed Journal)

  • Publication Type: Article / Article
  • Volume: 11 Issue: 2
  • Publication Date: 2023
  • Journal Name: Mühendislik Bilimleri ve Tasarım Dergisi
  • Journal Indexes: TR DİZİN (ULAKBİM)
  • Page Numbers: pp.519-534
  • Van Yüzüncü Yıl University Affiliated: Yes

Abstract

Çaldıran fault zone and its vicinity are significant seismically active zone that generated many destructive earthquakes. In this fault system, the last of these major earthquakes occurred on November 24, 1976 (Ms = 7.3). Therefore, based on the seismotectonic b-value, earthquake probability, recurrence times and Coulomb stress changes, we investigate the future earthquake potential and positive/negative stress changes in this fault zone. The events with a magnitude greater than 3.6 are used to investigate stress transfer direction regarding the seismotectonic parameters. The results indicate that the regions having smaller b-values are obtained along with the southeast part of the Çaldıran fault zone, whilst higher b-values are calculated around the eastern part of Lake Van. On the other hand, the northeast part of the Çaldıran fault zone represents current stress accumulation. Similarly, the Coulomb stress variations of the 1976 earthquake show that stress accumulated at different depths in the northwest of this fault system. In addition, considering the long-term slip rates and horizontal offset in previous studies, the recurrence time of the earthquakes has approximately 302 years for a magnitude greater than 6.0. Finally, these comprehensive analyses explain the implications of seismic hazard evaluation and forecasting of possible next earthquake occurrences in this region.