Ground-motion prediction equations for the western Kingdom of Saudi Arabia

Ground-motion prediction equations (GMPEs) for the western Kingdom of Saudi Arabia are developed by employing a mixed-effects regression model to modify the Boore and others (2014) Next Generation Attenuation-West2 (NGA-West2) project GMPEs. NGA-West2 addressed several key issues concerning GMPEs for shallow crustal earthquakes in active tectonic regions. However, the NGA-West2 input data do not include many earthquakes in extensional regimes, such as those occurring in Saudi Arabia. This deficiency is redressed by calculating a magnitude scaling of the new Saudi Arabia-specific GMPEs compared to those of Boore and others (2014). Furthermore, there is a clear difference in distance scaling for the Saudi Arabian GMPEs in comparison with the NGA-West2 GMPEs. This difference is especially significant at large distances and is mainly due to lower anelastic attenuation in the crystalline crust of western Saudi Arabia. Our empirical data demonstrate that the GMPEs presented here are in good agreement with observed earthquake ground motions in western Saudi Arabia.