A local ground-motion predictive model for Turkey, and its comparison with other regional and global ground-motion models

We examined the differences between the ground-motion estimations of local and global prediction equations and explored some seismological parameters that may explain these differences. To achieve this objective, we first derived a set of ground-motion prediction equations (GMPEs) for estimating peak horizontal acceleration, velocity, and pseudospectral acceleration using the recently compiled Turkish ground-motion database. The new GMPEs are comparable with the recent global GMPEs in terms of model sophistication, and they are based on a well-studied national dataset. Using global GMPEs from the Next Generation Attenuation of Ground Motions project (Power et al., 2008) and the pan-European Akkar and Bommer (2010) model, we observed that the discrepancy between local and global GMPEs is more prominent at small magnitudes provided that the GMPEs possess similar magnitude limits. Our more detailed comparisons with the pan-European Akkar and Bommer (2010) predictive model, as well as with the estimations from a combined Italian and Turkish accelerometric dataset, indicate that depth can be of importance for delineating the differences between local and global GMPEs.