Fault modeling around southern Anatolia using the aftershock sequence of the Kahramanmaraş earthquakes (Mw = 7.7 and Mw = 7.6) and an interpretation of potential field data.


Büyüksaraç A., Bektaş Ö., Alkan H.

Acta Geophysica, no.01192, pp.1-12, 2023 (SCI-Expanded)

  • Publication Type: Article / Article
  • Publication Date: 2023
  • Doi Number: 10.1007/s11600-023-01192-4
  • Journal Name: Acta Geophysica
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication Abstracts, Compendex, Geobase, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.1-12
  • Van Yüzüncü Yıl University Affiliated: Yes

Abstract

On February 6, 2023, southeastern Türkiye experienced devastating doublet earthquakes (Mw = 7.7 and Mw = 7.6) with a series of aftershocks along the East Anatolian Fault Zone. The mainshocks were followed by ~ 15,000 aftershocks mainly distributed in the NNE–SSW direction, including ~ 400 events with an Mw ≥ 4.0 in the following 30 days. Although many moderate to large earthquakes have occurred in the historical and instrumental periods of this region, these double earthquakes and their aftershocks majorly impacted lives and released great seismic energy. In this study, we interpret the gravity-magnetic data and the epicenter and hypocenter distributions of the aftershocks to correlate the tectonic structures and the active fault zones. The results of potential field anomalies reveal that the rotational anomalies in the southwestward direction are associated with the tectonic structure of Anatolia. Results show that shallow aftershocks are associated with high-gravity anomalies, whereas deeper aftershocks are associated with low-gravity anomalies and they become shallower in places where gravity values increase. After the derivative transformations are applied to the magnetic anomalies, it is seen that the faults and regions of magnetic discontinuity are in good agreement. Consequently, the findings on gravity, magnetic anomalies and aftershock sequences demonstrate that the first mainshock occurred in the unbroken segment of the East Anatolian Fault Zone.