SYNTAGMA - Synthetic ground motions to support the Fennoscandian GMPEs

The relevance of near-field earthquakes to the safety of nuclear power plants (NPPs) in Fennoscandia is very high. De-aggregation from probabilistic seismic hazard assessment (PSHA) studies indicates that the prevailing source of hazard from ground accelerations of engineering interest is from mid-magnitude earthquakes at less than 50 km distance from the NPPs. Unfortunately, there are very few recordings of Fennoscandian earthquakes in the range of distances of this highest interest. We have developed a method to generate synthetic ground motions by physics-based modeling. Since the ground motion prediction (GMPE) is an essential part of PSHA computation we verify the simulation results with the G-16 GMPE (Graizer) developed for hard rock sites. The agreement between G-16 and our results is good at distances up to 30 km. Leader organisation: VTT Technical Research Center of Finland.