Simulating the seismicity induced by magmatic dikes with application to the 2000 dike propagation event at the Miyakejima volcano, Japan

Seismicity induced by fluid-filled intrusions, such as volcanic dikes or hydraulic fractures in industrial settings for the exploitation of georesources, can cause substantial damage to human communities and infrastructure. Thus, studying the spatio-temporal evolution of dikes and associated observables, including deformation and seismicity rates, is important not only for academic purposes but also to improve our ability to evaluate hazards. In this thesis, I develop models for two scenarios of dikes propagating in an brittle-elastic medium and producing deformation, stress and seismicity. For my simulations, I take inspiration from the 2000 dike propagation event at Miyakejima volcano in Japan. In the first scenario I consider a dike propagating at a constant velocity, volume and shape. In the second scenario, the dike still has constant volume, but a decreasing topographic loading at the surface modifies its size and velocity. The seismicity is simulated through Coulomb stress and the rate-state modeling. The dike, which is the source of change of the stress field, is modeled using the boundary elements technique. My simulations replicate some features of the seismicity observed during the Miyakejima dike propagation event, including the migration of an isolated cloud of earthquakes and the lateral thinning of the cloud. I conclude my thesis by suggesting future extensions to the models and tests to carry out with data, to improve the models' potential of forecasting earthquake rates during magma intrusions and hydraulic fracturing operations.