A comprehensive analysis of the ground motions of the 2023 Kahramanmaraş, Türkiye earthquakes

With a focus on the dynamic characteristics of the ground motion recorded in Kahramanmaraş, Türkiye, this study provides an overview of the historical seismicity of the Eastern Anatolian Fault Zone (EAFZ) as well as the characteristics of the Pazarcik and Elbistan earthquakes (Mw=7.7 and Mw=7.6) that resulted in property loss and casualties on February 6, 2023. Analyzing the ground motion and local site effects for the earthquake region has been the subject of extensive research in the past. Ground Motion Prediction Equations (GMPEs) are one of the evaluation techniques utilised in the literature. Previous research employing this approach and other techniques suggested that the earthquake region’s geotechnical and seismological conditions are complicated, particularly in Hatay City. In this study, to further investigate the ground motions, six GMPEs, which were previously proposed for the USA, Europe and the Middle East, are adopted. The findings of this study are integrated with those from previous research for comprehensive assessments. This study shows that the PGA of the Kahramanmaraş earthquakes cannot be fully predicted using GMPEs, which use epicentral distance (Repi) in the equation. As a result, further research into rupture distance (Rrup) or Joyner-Boore distance (Rjb)-based equations is necessary. Also, the complexity of the region (i.e., irregularities present in alluvial deposits) and the high PGA values could be responsible for such a result. This study emphasizes the region’s need to have more sophisticated GMPEs in the future.