Akademik Veri Yönetim Sistemi
TURKIYE JEOLOJI BULTENI-GEOLOGICAL BULLETIN OF TURKEY, cilt.51, sa.2, ss.63-76, 2008 (ESCI, TRDizin)
Determination of source, path and site characteristics in the Western Anatolia Region, which is one of the most seismically and tectonically active continental regions in the world, is a very important issue in the sense of scaling the seismic hazard of a possible large earthquake. For that reason, the soil behavior of the sedimentary fills of the Gediz Graben in the region was investigated. At first, site amplifications and natural resonance frequencies of the two sites (IZM/Izmir and BRN/Bornova stations) in Izmir were determined using micro and moderate sized earthquake data from two accelerometers operated by the Turkish National Strong Motion Network. After that, the detailed geology, stratigraphy, seismic reflection, gravity, resistivity, hydrogeology, water supply and well-logging studies in the graben were examined in order to obtain vertical distributions of average velocity and regional (anelastic) attenuation values for the sedimentary fill of the Gediz Graben. The Estimated vertical velocity and anelastic attenuation distributions were used as input parameters for the Quarter-Wavelength Approximation in order to determine an average site amplification function. Utilizing these amplification values, the Peak Ground Acceleration (PGA) and Spectral Acceleration (5% damped spectral acceleration, SA) values of a hypothetical earthquake, with M-w=7.0 and hypocentral depth=10 km, were simulated in order to see the interaction between structures and this event, at different distances on the sedimentary fill of the Gediz Graben. The results implied that an obtained maximum PGA value is 0.42 g and the maximum horizontal SA value is 1.2 g at 0.3 sec at the epicentral location of the hypothetical earthquake. Dominant periods are 0.3 sec for hypocentral distances of 10-30 km and 0.5 sec for the hypocentral distance of 100 km in the Gediz Graben.