Evolving the Fennoscandian GMPEs (EVOGY)

Evolving the Fennoscandian GMPEs (EVOGY) project was targeted at proposing an updated ground motion prediction equation (GMPE) for probabilistic seismic- hazard analyses of Finnish nuclear installations. We collected and archived the available recordings of earthquakes in Fennoscandia and created a database with all spectral components important for engineering evaluation.
For developing the GMPE, we used the backbone curves of the G16 equation proposed by Graizer (2016) for central and eastern North America. We adjusted the peak ground acceleration (PGA) prediction of G16 to cover lower magni-tudes and very hard-rock conditions of Fennoscandia, but keep it unchanged for magnitudes above Mw4. We adjust the normalized spectral shape prediction of G16 using combined Fennoscandian and NGA-East data for very hard rock.
We evaluated the mean prediction and error using the calibration data, and compared the adjusted GMPE to the subset of hard-rock recordings from the NGA-East database. We used a set of synthetic ground motions created using a hybrid modeling method to confirm the prediction in the near field.
We conclude that the adjusted G16 formulation is adequate for predicting ground motions in Fennoscandia. Due to the compatibility with the original G16 backbone curve and additional comparisons, we estimate that the validity of the proposed formulation is up to the range of 2.0≤Mw≤6.5 and 0≤Rrup≤300km for the hard-rock conditions.