Fig. 14

Effect of the terminal settling velocity of the ash particles on the extension of the hazard zone. The hazard zone is represented by the area enclosed by the 5 % probability contour of a deposit loading equal to 300 kg/m². Eruption column ranges between 16 and 18 km, the diffusion coefficient between 3000 and 5000 m²/s. We use radio-sounding between 1962–1976 (Aeronautica Militare) recorded at Brindisi (BRIN), radio-sounding between 1962–1976 recorded at Pratica di Mare station between 1995–2013 (LIRE), 6-h NOAA-CIRES Reanalysis-2 model between 1991–2010 (NOAA) and of ECMWF ERA-Interim Full Resolution model between 1991–2010 (ERA)