It is well known that the seismicity in the Groningen area is due to gas extraction. The dynamics of how the site and rate of extraction is related to the magnitude and frequency of seismicity, however, is not understood. In a synergetic collaboration between the Department of Applied Mathematics at the University of Twente and the Department of Earth Sciences at Utrecht University, we develop state-of-the-art tools to comprehensively address this extraction-seismicity causality.
Our work package explored the estimation of earthquake hazard using adaptive kernel estimation. The crucial parameter in this approach is the bandwidth that governs the amount of spatial smoothing. We derived asymptotically optimal choices for this parameter as well as a practical non-parametric scheme.
A second line of research is concerned with modifications of the rate-and-state models that relate seismicity to gas extraction and measured pore pressure and that are widely used in the geo-sciences to allow for uncertainty in the pressure measurements.
The project is part of a larger NWO programme (DEEPNL) that was set up in response to the advice of the Dutch Safety Board: ensure that there is a structural and long-term research programme into the gas-extraction related problems in Groningen.
Results
M.N.M. van Lieshout. Infill asymptotics and bandwidth selection for kernel estimators of spatial intensity functions. Methodology and Computing in Applied Probability 22:995-1008, 2020.
M.N.M. van Lieshout. Infill asymptotics for adaptive kernel estimators of spatial intensity functions. Australian and New Zealand Journal of Statistics 63:159-181, 2021.
Z. Baki and M.N.M. van Lieshout. The influence of gas production on seismicity in the Groningen field. Proceedings of the 10th International Workshop on Spatio-Temporal Modelling, C. Comas and J. Mateu (Eds.), 163-167, 2022.
M.N.M. van Lieshout and Z. Baki. Exploring seismic hazard in the Groningen gas field using adaptive kernel smoothing. Mathematical Geosciences, published online, July 24, 2023.
M.N.M. van Lieshout. Non-parametric adaptive bandwidth selection for kernel estimators of spatial intensity functions. Annals of the Institute of Statistical Mathematics, published online, December 22, 2023.