A regional site-response model for the Groningen gas field

Abstract

A key element in the assessment of induced seismic hazard and risk due to induced earthquakes in the Groningen gas field is a model for the prediction of ground motions. Rather than use ground - motion prediction equations (GMPEs) with generic site amplifica tion factors conditioned on proxy parameters such as V S30 , a field - wide zonation of frequency - dependent non - linear amplification factors has been developed. Each amplification factor is associated with a measure of site - to - site variability that captures th e variation of V S profiles and hence amplification factors across each zone, as well as the influence of uncertainty in the modulus reduction and damping functions for each soil layer. This model can be used in conjunction with predictions of response spec tral accelerations at a reference rock horizon at a depth of about 80 0 m to calculate fully probabilistic estimates of the hazard in terms of ground shaking at the surface for a large region potentially affected by induced earthquakes.