Probability hazard map for future vent opening at Etna volcano (Sicily, Italy).

Abstract

The frequent flank eruptions occurrence at Mt. Etna lead to a high volcanic hazard that, linked to a population of nearly one million people dwell on its flanks, poses a high volcanic risk. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management), we developed a near real-time computer-assisted analysis and probabilistic evaluations that provide the identification of the areas prone to the highest vent opening hazard. The use of a code such BET_EF (Bayesian Event Tree_Eruption Forecasting) provide us a long-term hazard map mainly based on the past behaviour of the Etna volcano. The near real-time additional seismic and ground deformation data allow the long-term hazard map switches into a short-term future vent opening one. The short-term future vent opening was computed starting from the evaluation of deformation field over Etna surface. Analytical inversion of deformation and seismic data is performed to find the parameters of a magmatic source in an elastic, isotropic and homogeneous half-space and forward model is performed to compute the displacement field over Etna surface. We modelled the final intrusion of the Mount Etna May 2008 eruption that was accompanied by a violent seismic swarm and marked by ground deformation recorded at GPS stations. Results suggest a good accordance between the higher probability area and the real vent occurrence.