FEST: 'What simulations of induced earthquakes in Groningen tell us'

Friday Earth Sciences Talk by Dr Ylona van Dinther

Induced earthquakes in Groningen have overshadowed the Dutch news for nearly a decade. I will show you what have we learned from combining the unprecedented dataset with physics-based numerical models. We find fault healing allows for the nucleation of earthquakes in rocks previously considered as stable. Healing makes rocks initially stronger, increasing the size of the first induced earthquake, but significantly decreasing hazard of subsequent events. Adopting heterogeneous material properties shows a rupture beyond the reservoir is unlikely.

Simulating a sequence of 25 earthquakes suggests spontaneous earthquake nucleation and arrest is only possible if observational constraints are respected. This means critical sizes measured in the laboratory as well as re-interpretations of fault geometry should be respected. Preliminary results also suggest that rupture jumping is unlikely if reservoir widths are limited. These processes and complexities typically not considered generally limit the hazard of induced earthquakes.

With the FEST, we intend to bring the departments of Earth Sciences and Physical Geography together. The aim is to present (mostly) Utrecht-based Earth Sciences in an accessible way, primarily in order to stay familiar with each other’s work across disciplines. Simultaneously, this provides an excellent platform to help (in particular MSc.) students in their orientation on possible graduation specialisations and future careers.