Updating the assessment of lava flow hazards at Etna volcano

Lava flow hazard is a significant geological threat associated with volcanic activity. Understanding and quantifying this hazard is critical to protect communities, infrastructure and the environment, especially in active volcanic areas such as Mount Etna (Sicily, Italy). In this work, we propose a new probabilistic methodology for lava flow hazard assessment on Mount Etna based on a 4,000-year eruption dataset and accurate statistical analyses. The methodology combines the probability of future vent opening, the probabilities of occurrence of individual eruption classes and the weighted combination of lava flow inundation maps. These maps are obtained using representative scenarios for each eruption class, based on statistical analyses of duration and lava volume. The results are two maps, one for flank and one for summit eruptions, that provide the probabilities that a specific area will be affected by lava flow inundation during specific time intervals. Furthermore, we present the first attempt to assess the hazard of both types of eruptions occurring on Mount Etna. These hazard maps could be fundamental tools, especially in the long term, for emergency preparedness and territorial planning, allowing to easily identify the areas where future eruptions could have a greater impact. Furthermore, they could help local authorities to manage ongoing eruptions, making targeted decisions and mitigating the associated risk.