Received: 10 March 2020 Revised: 19 July 2020 Accepted: 22 September 2020 DOI: 10.1002/eqe.3367 SPECIAL ISSUE PAPERS Earthquake ground motion modeling of induced seismicity in the Groningen gas field R. Paolucci 1 I. Mazzieri 2 G. Piunno 1 C. Smerzini 1 M. Vanini 1 A.G. Özcebe 3 1 Department of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy 2 Department of Mathematics, Politecnico di Milano, Milan, Italy 3 EUCENTRE—European Centre for Training and Research in Earthquake Engineering, Pavia, Italy Correspondence G. Piunno, Department of Civil and Envi- ronmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133, Italy. Email: giovanni.piunno@polimi.it Abstract A physics-based numerical approach is used to characterize earthquake ground motion due to induced seismicity in the Groningen gas field and to improve empirical ground motion models for seismic hazard and risk assessment. To this end, a large-scale (20 km × 20 km) heterogeneous 3D seismic wave propagation model for the Groningen area is constructed, based on the significant bulk of available geological, geophysical, geotechnical, and seismological data. Results of physics-based numerical simulations are validated against the ground motion recordings of the January 8, 2018, M L 3.4 Zeerijp earthquake. Taking advan- tage of suitable models of slip time functions at the seismic source and of the detailed geophysical model, the numerical simulations are found to reproduce accurately the observed features of ground motions at epicentral distances less than 10 km, in a broad frequency range, up to about 8 Hz. A sensitivity analysis is also addressed to discuss the impact of 3D underground geological features, the stochastic variability of seismic velocities and the frequency dependence of the quality factor. Amongst others, results point out some key features related to 3D seismic wave propagation, such as the magnitude and distance dependence of site amplification functions, that may be relevant to the improvement of the empirical models for earthquake ground motion prediction. KEYWORDS earthquake ground motion, induced seismicity, Groningen gas field, high-performance com- puting, physics-based numerical simulations 1 INTRODUCTION The Groningen gas field, in the Netherlands, has been in operation since mid-1960s for hydrocarbon production. Since 1991, a moderate earthquake activity was recorded in the area that was attributed to nontectonic origin and directly related to the reservoir depletion. 1 An accelerometric network was installed in the area, that recorded a gradual increase of seis- micity starting from about 2003 (Figure 1). However, it was only after the August 16, 2012 Huizinge earthquake with local magnitude (M L ) 3.6, causing a maximum Mercalli intensity of the 6th degree, that a series of research studies was pro- moted for the hazard and risk assessment for induced seismicity in the area. 2 In spite of the substantial reduction of the gas production activity, further important earthquakes occurred, such as the M L 3.4 Zeerijp event on January 8, 2018, and the M L 3.4 on May 22, 2019. Earthquake Engng Struct Dyn. 2020;1–20. © 2020 John Wiley & Sons Ltd. 1 wileyonlinelibrary.com/journal/eqe