RESEARCH AND DEVELOPMENT
3D ground motion modeling
KEM-04: Project on 3D Ground motion modelling and data analysis for understanding heterogeneity effects
in the Groningen gas field (the Netherlands)
Project sponsor: Dutch Minister of Economic Affairs
Project partners: Fugro, Politecnico di Milano,
GR8-GEO, Hanze Hogeschool Groningen
The KEM-04 project aimed at addressing a number of important issues related to the Groningen seismic risk assessment, in particular ground motion modelling (GMM) component.
The workflow involved collection and analysis of recorded ground motions, 3D numerical simulations using the SPEED code and the empirical Greens function approach, analysis of local soil response and comparison with the V5 GMM.
Results are relevant for better understanding the spatial variability of observations, for constraining uncertainties and for characterizing the spatial variability in ground motion fields. Importantly, the chosen project approach has shown convincingly that advanced 3D physics-based numerical approaches to characterize earthquake ground motion are feasible and can be a diagnostic tool to understand the relevance of specific geologic conditions.
Finally, the project led to recommendations for the evolution/improvement of the GM component of the hazard and risk model.
Methods and tools innovations for seismic risk assessment
Project sponsor: EU
Project partners: Geodynamique & Structure, EDF R&D, GEM
Launched in September 2020, METIS is a 48 month long Horizon 2020 project funded under the Euratom research and training programme that brings together 16 partners from 9 different countries. METIS mission is to develop and improve tools and methodologies employed in seismic safety assessments of nuclear reactors and translate this research into practice for industry use.
Seister is currently involved in WP3 and WP4 and our major objective is to develop a method to simulate ground motions for reference rock conditions by first removing source and site terms from small magnitude records by spectral inversion techniques and then using empirical Green’s functions simulations for larger magnitudes.
This approach is applied to the METIS test case in WP3.
SIGMA -2 project
Constraining seismicity parameters in PSHA application using strain rate estimates in a Bayesian framework
Project sponsor: Orano Year: 2018/22
Predicting recurrence rates of large Mw earthquakes is associated to large uncertainty. These uncertainties and the strategies adopted to quantify and model the uncertainties may affect the PSHA results in particular at large return periods. There is the need to identify in complex logic-trees the most and least plausible combinations of parameters and to adjust the weighting scheme if needed, to be more representative of the current state of knowledge.
To this aim, we evaluated the benefit of using the annual seismic strain rate to better constrain the earthquake scenarios accounted for in PSHA. This approach is implemented at two selected sites in South-Eastern France.