S13F-08:
TOWARD NON-ERGODIC AND SITE-SPECIFIC PROBABILISTIC SEISMIC HAZARD ASSESSMENT: REQUIREMENTS FOR THE NEXT GENERATION OF STRONG MOTION NETWORK AND DATABASES.

Monday, 15 December 2014: 3:25 PM
Fabrice Cotton1,2, Olga Joan Ktenidou2, Boumediene Derras2,3, Zafeiria Roumelioti4, Bard Pierre-Yves2 and Fabrice Hollender2,5, (1)Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany, (2)ISTerre, Universite Joseph Fourier Grenoble, CNRS, Grenoble, France, (3)Université Dr Tahar Moulay, Saïda, Algeria, (4)Aristotle University Thessaloniki, Thessaloniki, Greece, (5)CEA, Cadarache, France
Abstract:
Ground-motion models used in engineering seismology are usually calibrated on global databases that are usually created by mixing data from different regions. These models also assume that the ground-motion variability observed in a global dataset is the same as the variability in ground motion at a single site-source combination. This assumption is referred to as the ergodic assumption.

New data give a unique opportunity to remove the ergodic assumption and take into account regional source, path and site specificities. Using recent data analysis performed on the EUROSEISTEST valley (Greece) and global ground-motion datasets (Kiknet, Knet, NGA2 and the European strong-motion databases) we will show the impact of source parameters, site monitoring and site-characterisation on the uncertainty of the ground motion estimates and associated hazard curves.

Our results suggest that future strong-motion networks should use higher sampling rates (to better evaluate site-specific high frequency attenuations) and record both strong and weak motions (to evaluate single-station sigma). These results also quantify the impact of a better characterisation of source parameters (depth, fault maturity, source to site distances) ans site parameters on ground-motion models.

We finally will show how new networks and high-level strong-motion databases may help to built consistent ergodic PSHA at a regional scale and non-ergodic, site specific,  PSHA.