Probabilistic seismic hazard assessment for east anatolian fault zone using planar source models

Menekşe, Akın
The objective of this study is to perform probabilistic seismic hazard assessment (PSHA) using planar seismic source characterization models for East Anatolian Fault Zone (EAFZ) and to update the design ground motions to be used in the region. Development of planar seismic source models requires the definition of source geometry in terms of fault length, fault width, fault plane angles and segmentation points for each segment and associating the observed seismicity with defined fault systems. This complicated task was performed with the help of Updated Active Fault Maps of Turkey (Emre et al., 2012), previously conducted geological site studies in the literature, and Unified Instrumental Earthquake Catalogue of Turkey (Kalafat et al., 2011). The state-of-the-art seismotectonic model developed in this study includes the fault segments, rupture sources, rupture scenarios, and fault rupture models that are combined with composite magnitude distribution model to properly represent thecharacteristic behavior of faults. This study is also novel in terms of the employed ground motion characterization framework. Recently published global Next Generation Attenuation (NGA-West2) ground motion prediction models (Bozorgnia et al., 2014) and Turkey-Adjusted NGA-West1 models (Gülerce et al., 2015) are used in the ground motion logic tree with equal weights. The results are presented in terms of the hazard curves and deaggregation of the hazard for six selected locations (Bingöl, Elazığ, Kahramanmaraş, Osmaniye, Pütürge, and Hasanbeyli) and compared with the Turkish Earthquake Code (TEC, 2007) requirements. Seismic hazard maps for accepted hazard levels in TEC (2007) for different spectral periods and forgeneric rock (VS30=760 m/s and VS30=1100 m/s) site conditions are also provided. Results of this study will provide an update of the previous seismic hazard maps of EAFZ and design ground motions proposed for the region.