PROBABILISTIC SEISMIC HAZARD ASSESSMENT FOR THE NETHERLANDS

This probabilistic seismic hazard analysis for The Netherlands is base d on the catalogue of European earthquakes published by the Commission of the European Communities. The seismic hazard is assessed by applyi ng a modified version of the McGuire program. This method uses for eac h seismotectonic zone a linear frequency-intensity relation, an upper bound of intensity, an average depth for large earthquakes and an azim uth-dependent attenuation. It assumes a Poisson process for large eart hquakes. The annual probability versus intensity is calculated for sit es at gridpoints with 7 km spacing. Hazard intensity maps are presente d 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 VI II for a 0.0001 annual probability and is decreasing to the north-west in line with the seismicity.