Phreatomagmatic ash from the ongoing eruption of Etna reaching the Greek island of Cefalonia

Abstract

On October 26, 2002, Etna volcano, Sicily (southern Italy), entered a new eruptive phase, characterised by the usual effusive activity from fissure vents located both on the southern and on the northern sector of the summit area. In addition, explosive events of unusual intensity were recorded at the beginning of the eruption and produced a substantial plume rich in fine ash particles and steam. On October 27, fine ash from the plume, blown by the wind, was reported falling on the island of Cefalonia, Greece, which is located approximately 500 km east of the volcano. In this communication, we report on the study of fine ash from the eruption as collected on Cefalonia. We elaborate on the nature of the peculiar type of explosion mechanism that led to such an unusual manifestation of Etna, which is phreatomagmatism. This finding draws a new picture of the eruptive scenario of this active volcano, and requires a careful evaluation of the hazard that similar events might pose in the future. Not just the surroundings of the volcano but also the aviation corridors of the southern Mediterranean area could be potentially affected.