A Test of the Applicability of NGA Models to the Strong Ground-Motion Data in the Iranian Plateau

Abstract

The Next Generation Attenuation (NGA) project has now published several new sets of empirical ground-motion prediction equations (GMPEs) for PGA, PGV, and response spectral ordinates. These models significantly advance the state-of-the-art empirical ground-motion modeling and account for many effects that have not been directly accounted for in the existing Iranian GMPEs. Assuming that the present strong-motion database in Iran is unlikely to drastically change in the near future, the question we ask in this study is: Can the NGA models be applied in Iran? In order to answer this question, the NGA models of Boore and Atkinson [2008], Campbell and Bozorgnia, [2008], and Chiou and Youngs [2008], which are shown to be representative of all NGA models, are compared with the Iranian strong-motion database. The database used in this study comprises 863 two-component horizontal acceleration time series recorded within 100 km of epicentral distances for 166 earthquakes in Iran with magnitudes ranging from 4.0–7.4. The comparisons are made using analyses of residuals. The analysis indicates that the NGA models may confidently be applied within the Iranian plateau. To provide more reliable constraint on finite-fault effects and nonlinear site response in the Iranian equations, it would be useful to drive new GMPEs based on a merger of the NGA and Iranian databases.