PhD position on constraining the maximum earthquake magnitude in Groningen using 3D multi-physics,...

The Department of Earth Sciences is now looking for a highly-motivated, high-potential applicant to fill a PhD position on constraining the maximum earthquake magnitude in Groningen using 3D multi-physics, data-driven modelling (4 years).

The seismic hazard due to induced seismicity in the Groningen gas field (the Netherlands) is largely determined by the maximum earthquake magnitude (Mmax) and the likelihood of its scenarios. Mmax is thus critical for political decision-making and hazard perception by society. Current Mmax estimates are determined using extrapolations from observed small earthquakes using event-based statistics and expert judgement. A physical basis is thus largely missing. Such a physical component is consistently challenging to include in any probabilistic seismic hazard assessments (PSHA) due to very high demands on computational costs. Particularly, the challenge in Groningen is to include the key physical processes on a particularly complex network of many, curved and intersecting faults. The PhD candidate will utilise recent advances in several computational communities to advance physics-based PSHA and provide physics-based estimates of Mmax in Groningen.

The PhD candidate will develop a 3D multi-physics, data-driven framework through linking two existing state-of-the-art methods and adding a third, novel semi-analytical model that will be further developed. First, probabilistic fault stresses will be provided by a semi-analytical reservoir simulator MACRIS1. These fault stresses will take into account improved geometries of the Groningen faults and the production history of the field. Subsequently, these pre-earthquake fault stresses, along with friction parameters derived in the laboratory in Utrecht on Groningen rocks, will be exported to 3D dynamic earthquake rupture simulations powered by High Performance Computing in SeisSol 2,3,4,5. Third, these dynamic simulations will serve to validate and extend a semi-analytical model based on linear elastic fracture mechanics (LEFM) theory for straight faults6 to complex fault geometries. This theory allows for a fast and probabilistic assessment of the likelihood of different Mmax scenarios across the field, while accounting for key uncertainties. The aim is that the results of this PhD project will be embedded in the Groningen risk assessment framework housed at the Geological Survey of the Netherlands (TNO). In the future, this new physical framework may also be of great value in determining the earthquake risk for induced and natural earthquakes in the Netherlands and worldwide. This could thus provide an important contribution in allowing for a safe and sustainable usage of the subsurface to facilitate our society’s transition to sustainable energy. The project can therefore serve as a stepping stone for a career in fundamental earthquake physics or various societally and economically relevant industries.

This project is part of DeepNL , a long-term Dutch research programme into a better understanding of how the deep subsurface behaves under the influence of human interventions, e.g. in the gas reservoir in the province of Groningen (The Netherlands), and that aims to develop a knowledge base for geothermal energy extraction and underground CO2 and hydrogen storage. The research team includes project leader Dr Ylona van Dinther (UU), Prof. Dr Jan-Diederik van Wees (TNO, UU), Dr Alice Gabriel (LMU Munich), Prof. Dr Jean-Paul Ampuero (GEOAZUR), Dr Thibault Candela (TNO), Dr Loes Buijze (TNO) and Prof. Dr Liviu Matenco (UU). Collaborators also appointed on the project include Dr Thomas Ulrich (LMU Munich) and Dr Huihui Weng (GEOAZUR). The research will mainly be performed at Utrecht University, but extended stays at the partner institutes in Germany and France are included in the project planning.

Up to 10% of the candidate's time will be dedicated to assisting in the BSc and MSc teaching programmes of the Department of Earth Sciences. A personalised training programme will be set up, mutually agreed on recruitment, which will reflect the candidate's training needs and career objectives.

References