Application of BET_EF to Mount Etna: a retrospective analysis (years 2001-2005)

Advances in volcano monitoring and forecasting need a multidisciplinary collaborative framework. In light of this, a BayesianEvent Tree (BET) approach was performed by the application of the BET for Eruption Forecasting (BET_EF) code to analyze the space-timedistribution of the volcanic activity of Mount Etna from 2001-2005. First, a reliable monitoring dataset was set up after some sessions toelicit geophysical, volcanological and geochemical ‘precursor’ parameters. A constant unrest probability of 100%, with a magmainvolvement usually greater than 95%, was computed throughout the time period analyzed. Eruption probabilities higher than 90% wereestimated a few days before the onsets of the 2001 and 2002-2003 flank eruptions. Values slightly higher than 75% were observed during the lavafountaining period in June-July 2001. However, the probabilities flattened to around 30% for the 2004-2005 flank eruption. With suitabledata, a good depiction of the actual location of the eruptive scenario for the 2001 and 2002-2003 events was provided. Conversely, the size of theeruptions was not indicated.