PROBABILISTIC SEISMIC HAZARD ASSESSMENT FOR THE NETHERLANDS

This probabilistic seismic hazard analysis for The Netherlands is based on the catalogue of European earthquakes published by the Commission of the European Communities. The seismic hazard is assessed by applying a modified version of the McGuire program. This method uses for each seismotectonic zone a linear frequency-intensity relation, an upper bound of intensity, an average depth for large earthquakes and an azimuth-dependent attenuation. It assumes a Poisson process for large earthquakes. The annual probability versus intensity is calculated for sites at gridpoints with 7 km spacing. Hazard intensity maps are presented for the annual probabilities of occurrence 0.02, 0.01, 0.005, 0.001, 0.0004 and 0.0001. A rough estimate of the error is approximately one half of an intensity unit for all probabilities. The highest seismic hazard in The Netherlands is found in the south-east with intensity VIII for a 0.0001 annual probability and is decreasing to the north-west in line with the seismicity.