New Generation of Probabilistic Seismic Hazard Assessment for the Area Cologne/ Aachen Considering the Uncertainties of the Input Data

摘要

A new earthquake catalogue for central, northern and northwestern Europe with unified M_w magnitudes, in part derived from chi-square maximum likelihood regressions, forms the basis for seismic hazard calculations for the Lower Rhine Embayment. Uncertainties in the various input parameters are introduced, a detailed seismic zonation is performed and a recently developed technique for maximum expected magnitude estimation is adopted and quantified Applying the logic tree algorithm, resulting hazard values with error estimates are obtained as fractile curves (median, 16% and 84% fractiles and mean) plotted for pga (peak ground acceleration; median values for Cologne 0.7 and 1.2 m/s~2 for probabilities of exceedence of 10% and 2%, respectively, in 50 years), 0.4 s (0.8 and 1.5 m/s~2) and 1.0 s (0.3 and 0.5 m/s~2) pseudoacclerations, and intensity (I_0 = 6.5 and 7.2), For the ground motion parameters, rock foundation is assumed. For the area near Cologne and Aachen, maps show the median and 84% fractile hazard for 2% probability of exceedence in 50 years based on pga (maximum median value about 1.5 m/s~2), and 0.4 s (>2 m/s~2) and 1.0 s (about 0.8 m/ s~2) pseudoaccelerations, all for rock. The pga 84% fractile map also has a maximum value above 2 m/s~2 and shows similarities with the median map for 0.4 s. In all maps, the maximum values fall within the area 6.2-6.3 deg E and 50.8-50.9 deg N, i.e., east of Aachen.