Forecasting the evolution of the current unrest of Campi Flegrei by defining anomalies through experts’ elicitation

The Campi Flegrei caldera, Italy, is considered one of the most high-risk volcanic areas on the planet due to its location within the metropolitan area of Naples. Campi Flegrei caldera is currently undergoing unrest. The unrest is linked to an uplift phase that started in 2005, which is accompanied by gas emissions and volcano-tectonic seismicity. Owing to the limited knowledge of the plumbing system and the pre-eruptive processes, tracking the evolution of a volcanic unrest is often based on probabilities obtained by experts’ elicitation. In this work, we present the daily variation of the probability that the unrest is driven by a shallow magma movement and the monthly probability of eruption based on the Bayesian Event Tree for Eruption Forecasting (BET_EF) model calibrated for Campi Flegrei by means of the outcomes of the VI experts’ elicitation carried out in 2015. The results show that according to the interpretive framework provided by experts, the probability that the mechanism behind the current unrest is shallow magma movements is not negligible, but the monthly probability of eruption remained overall constant during the entire period.