EMPIRICAL ATTENUATION RELATIONSHIP OF PEAK GROUND ACCELERATION FOR EASTERN MARMARA REGION IN TURKEY

A new attenuation relation for peak ground acceleration ( PGA) in the Marmara region of northwestern Turkey has been developed. The data base consists of 751 horizontal components of peak ground acceleration recorded from 78 earthquakes, including the 1999 Izmit (M-w = 7.4) and the 1999 Duzce (M-w = 7.2) earthquakes. All the raw records are of the main earthquakes and their aftershocks. Baseline and instrument corrections have been applied to these raw records. Fast Fourier Transforms (FFT) have been calculated for all the records to select the high-pass and low-pass filters after these corrections. Multiple regression analyses have been used to calculate the relationship. The proposed attenuation relationship is