The 4–5 September 2007 lava fountain at South-East Crater of Mt Etna, Italy

Abstract

Continuous monitoring of paroxysmal eruptions at Mt. Etna (Italy) is performed from the Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania. In recent years, this activity has allowed us to study fallout deposits and track the evolution of eruptive phases. This communication reports on the paroxysm that occurred in the afternoon of 4 September 2007, when a powerful lava fountain started from South-East Crater, at the summit of Etna. The fountaining formed a plume up to 2 km-high for almost 12 h, causing abundant tephra fallout in the eastern sector of the volcano and emplacement of a thick, about 4 km-long clastogenic lava flow. Extensive area collection of tephra samples from the fallout deposit was performed within a few hours after the end of the paroxysm. We calculated a total erupted volume of 3.92–4.9×105 m3 and a total grain-size fitted by a Gaussian distribution with the mode of 0 ϕ and σ equal to 1.3. The total volume of the clastogenic lava flow deposit that resulted was 2–4×106 m3. The systematic study of paroxysms at Etna helps to better investigate Etnean-type lava fountains and to improve the classification of explosive activity on basaltic volcanoes.