Hakan B., Demirci A.
International Journal of Innovative Research in Engineering, cilt.7, sa.2, ss.17-24, 2026 (Hakemli Dergi)
Özet
The Datça Peninsula and its vicinity in southwestern Anatolia represent one of the most seismically active regions of Turkey, characterized by complex tectonic interactions between the Aegean extensional regime and the western termination of the North Anatolian Fault Zone. In this study, we investigate the frequency-dependent attenuation characteristics of body waves (P and S) using the extended coda normalization technique. We analyzed 299 three-component broadband seismic records from 668 earthquakes with local magnitudes (Ml) ≥ 3.5 that occurred between 2016 and 2022. The data were recorded at three regional seismic stations (DALY, DAT, and BODT) operated by the Kandilli Observatory and Earthquake Research Institute (KOERI). The analysis was performed at ten center frequencies ranging from 1.5 Hz to 18 Hz. The quality factor Q exhibits strong frequency dependence, following the power-law relationship Q(f) = Q₀fⁿ. For P waves, we obtained Qp = (17 ± 3)f1.40±0.07, while for S waves, Qs = (90.2 ± 20)f0.89±0.09. The Qs/Qp ratio averages approximately 1.63 for frequencies greater than 1 Hz, indicating that P waves attenuate more rapidly than S waves. These attenuation functions are essential input parameters for seismic hazard assessment, ground motion simulations, and focal mechanism studies in the region. The relatively low Q values reflect the highly fractured and heterogeneous crustal structure associated with the active extensional tectonics of the Aegean region