Source Parameters of the 2023 Kahramanmaraş Earthquake Aftershocks in the East Anatolian Fault Zone


Batman O., Akbaşak S., Demirtaş B. S., Tanircan G.

7th International Conference on Earthquake Engineering and Seismology (7ICEES), Antalya, Türkiye, 6 - 10 Kasım 2023

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Doi Numarası: 10.1007/978-3-031-57357-6_6
  • Basıldığı Şehir: Antalya
  • Basıldığı Ülke: Türkiye
  • İstanbul Gelişim Üniversitesi Adresli: Evet

Özet

Abundant strong motion recordings from the 6 February 2023 Kahramanmaraş and Elbistan Earthquake aftershocks provide invaluable information on source characteristics of events on the East Anatolian Fault Zone (EAFZ). In this study, basic source parameters of 61 moderate-size aftershock have been deduced from more than 200 strong motion recordings. Three approaches are employed to estimate the source corner frequency (fc) of events from S-wave spectra following the Brune’s source model fitting: visual inspection, numerical (RMSE), the spectral ratio of empirical Green’s functions (EGF). Power spectral ratio calculation of Andrews is utilized as the fourth approach. Source areas and stress drops are calculated following the circular static crack model and constant rupture velocity. Results indicate that the numerical and Andrews’ approaches provide the highest and lowest fc, respectively. All approaches are strongly sensitive to filter cut offs. Andrews’ approach underestimates the fc of small magnitude events (Mw < 4.9). Nevertheless, fc values converge to similar values for (Mw ≥ 5) for all approaches except the numerical fitting. The Mw calculated from seismic recordings are consistently lower than those reported by institutions. The stress drop results found in this study match with those of previous studies for the same region.