Assessment of seismic parameters for 6 February 2023 Kahramanmaras earthquakes

On February 6, 2023, Turkiye woke up with a strong ground motion felt in a wide geography. As a result of the Kahramanmaras, Pazarcik and Elbistan earthquakes, which took place 9 hours apart, there was great destruction and loss of life. The 2023 Kahramanmaras earthquakes occurred on active faults known to pose a high seismic hazard, but their effects were devastating. Seismic code spectra were investigated in Hatay, Adiyaman and Kahramanmaras where destruction is high. The study mainly focuses on the investigation of ground motion parameters of 6 February Kahramanmaras earthquakes and the correlation between ground motion parameters. In addition, earthquakes greater than Mw 5.0 that occurred in Turkiye were compared with certain seismic parameters. As in the strong ground motion studies, seismic energy parameters such as Arias intensity, characteristic intensity, cumulative absolute velocity and specific energy density were determined, especially considering the duration content of the earthquake. Based on the study, it was concluded that the structures were overloaded far beyond their normal design levels. This, coupled with significant vertical seismic components, is a contributing factor to the collapse of many buildings in the area. In the evaluation made on Arias intensity, much more energy (approximately ten times) emerged in Kahramanmaras earthquakes compared to other Turkiye earthquakes. No good correlation was found between moment magnitude and peak ground accelerations, peak ground velocities, Arias intensities and ground motion durations in Turkiye earthquakes. Both high seismic components and long ground motion durations caused intense energy to be transferred to the structures. No strong correlation was found between ground motion durations and other seismic parameters. There is a strong positive correlation between PGA and seismic energy parameter AI. Kahramanmaras earthquakes revealed that changes should be made in the Turkish seismic code to predict higher spectral acceleration values, especially in earthquake -prone regions in Turkiye.