The flank eruption history of Etna (1610-2006) as a constraint on lava flow hazard

Abstract

Data of the flank eruptions of Etna from over the last 400 years were extracted from the new geological map for the lava flow extensions and vent positions, and from the catalogs of historical eruptions for the eruption durations and lava volumes. The partially or widely hidden lava fields on the new geological map were retrieved from older geological maps. The distributions of the eruption durations and lava volumes were analyzed, with the definition of six eruptive classes for use in numerical simulations. The threshold values for the eruption durations and lava volumes were set at 45 days and at 35 × 106 m3 and 100 × 106 m3, respectively. A global analysis was performed on the whole volcano to evaluate the recurrence of the classes, and to estimate for each class the ranges, means and standard deviations of the durations, volumes and elevations of the main vent. The same analysis was repeated by subdividing the volcano into three sectors, which were defined on the basis of the distribution of the eruptive fissures over the last 15 ka. The classes have different recurrences across these various sectors, and different distributions of volumes, durations and elevations of the main vent. Finally, a lava flow resurfacing map that counts the number of lava flows on each given area of the volcano over the last 400 years was compiled and then normalized.