Revealing the seismic structure of the crust and upper mantle beneath Groningen (NL) through fine-scale teleseismic P-wave tomography

The Groningen region in the northern Netherlands has experienced significant induced seismicity over the past decade due to long-term gas extraction. In addition to hydrocarbon production, the area is considered promising for geothermal energy development and CO₂ storage, highlighting the need for a detailed understanding of the deep subsurface structure. Such knowledge is crucial for enhanced seismic hazard assessment and sustainable subsurface utilization.

We present a teleseismic P-wave tomographic study of the crust and upper mantle beneath the Groningen region, using data recorded by the regional seismic network over the past 6 years. Teleseismic P-wave arrivals are enhanced through stacking and alignment across the network to mitigate high noise levels and improve the accuracy of picking. The resulting first-arrival times form the input dataset for a tomographic inversion performed using FMTomo. Although the Groningen dataset is characterized by high noise levels, the large volume of available data combined with the stacking approach yields a robust set of arrivals suitable for inversion. Due to the dense dataset covering a relatively small region, the resulting model will offer a high-resolution P-wave velocity model of the crust and upper mantle beneath Groningen. This tomographic model provides a foundation for improved waveform simulations of induced seismicity, enhancing our understanding of seismic wave propagation and ground-motion patterns, and contributing to more accurate seismic risk evaluation for current and future subsurface activities.