Mapping long-term pyroclastic density current hazard in a caldera setting: application to Campi Flegrei caldera (Italy)

Abstract

The Campi Flegrei (CF) is an active volcanic area located in the Campanian Plain, along the Tyrrhenian margin of the Southern Appennines (Italy), dominated by the formation of a 12 km large, resurgent caldera. The nested Campi Flegrei caldera results from successive collapses related to the eruptions of the Campanian Ignimbrite (CI; 39.3±0.1 ka) and Neapolitan Yellow Tuffs (NYT; 14.9±0.4 ka). After the NYT eruption, volcanism was concentrated in three epochs of activity, alternating to periods of quiescence. The great majority of the eruptions have been explosive, variable in magnitude and also characterized by the generation of fallout, ash deposits and pyroclastic density currents (PDCs). We present here a methodology aimed at the construction of a probability map of PDC hazard of the CF area. At this stage, results are preliminary and will be improved by future research work. Nevertheless, first outcomes already provide numerous insights in the problem and contribute to define future research directions. In the study we had to cope with three different problems, related to different probability spaces: • constructing a probability map of the place of a new vent opening • giving a probability law to the area of invasion of a PDC from a fixed new vent • choosing a probability distribution for the uncertainty that affects the model itself To calculate the probabilistic simulations we used the R statistics software, and to plot the maps we used the ESRI platform.