Probabilistic seismic hazard maps for the North Balkan region

A set of seismic hazard maps, expressed as horizontal peak ground acceleration, have been computed for a large area of Central and Eastern Europe covering the North Balkan area (Former Yugoslavia, Hungary, Romania). These are based on: a) a compound earthquake catalogue for the region; b) a seismic source model of 50 zones compiled on the basis of tectonic divisions and seismicity, and c) a probabilistic methodology using stochastic (Monte Carlo) modelling. It is found that the highest hazard in the region comes from intermediate focus earthquakes occurring in the Vrancea seismic zone; here the hazard exceeds 0.4 g at return periods of 475 years. Special account has been taken of the directional nature of attenuation from this source.