Geological schematisation of the shallow subsurface of Groningen for site response to earthquakes for the Groningen gas field

The NAM is preparing a new "Winningsplan", to be submitted in 2016. For this new Winningsplan, a new generation of Ground Motion Prediction Equations (GMPEs) will be developed. The Geological model for the Site response at the Groningen Field (GSG-model) is, among other data sources, based on the beta version of GeoTOP (a 3D geological model of the Netherlands), provided by TNO Geological Survey of the Netherlands. The GSG-model built by Deltares consists of a map defining geological areas and voxel stacks containing stratigraphy and lithological class with depth. Additionally, a state-of-the-art Vs30 map was derived for the Groningen field +5 km buffer, taking into account Groningen-specific Vs relations and the geology from the GSG-model. This report describes the method for the construction and the results of version 1 of the GSGmodel, the quality checks performed on the model and recommendations for future versions. When more data becomes available, updates of the GSG-model are anticipated.