An integrated method to model volcanic processes and associated geophysical signals

Abstract

We present a numerical approach for modelling the complex sub-surface volcanic processes and associated geophysical signals. This method is based on the one-way coupling of the dynamics of a magmatic system and the response of the host rocks. The two systems are modelled independently, by two different numerical codes, that solve the equations of motion for the magmatic fluid and the equation of elasto-dynamics for wave propagation in the surrounding medium, respectively. Synthetic geophysical signals can be obtained and compared with those recorded by monitoring networks. The final aim is to understand how the complex physics of magma dynamics, coupled to its hosting medium, translates into geophysical data that can be measured and interpreted in order to understand sub-surface magma dynamics and forecast the short-term volcanic hazard. We applied this method to the Campi Flegrei volcanic system (southern Italy) and investigated the convection and mixing dynamics induced by the arrival of new CO2-rich magma into a hypothetical shallow magma chamber. The pressure waves originated by this system are propagated in the surrounding rocks, and the associated broad-band ground displacement and gravity anomalies are evaluated at the Earth’s surface.