Tsunamis Related to Volcanic Activity in Italy

Abstract

Tsunamis generated by volcanic eruptions are much less frequent than tsunamis produced by submarine earthquakes. In the Mediterranean Sea only 2 percent of the observed tsunamis were caused by volcanoes according to a recent study by Soloviev (1990). In Italy the percentage of events related to volcanic activity is distinctly higher than in any other country of the Mediterranean, which is expected since most of the European active volcanoes and volcanic areas may be found in southern Italy. Of the 21 cases of which some information is available, 11 were observed in the Campania coasts and are related to Vesuvius activity, 7 are due to volcanic activity in the Aeolian Islands some 50 km northwest of the Messina Straits, while the others are related to Etna and to volcanic activity in the Sicily Channel. The most significant of these tsunamis seems to be that occurred in December 1631 during the great Vesuvian eruption (16–18 December) that was observed in the entire Gulf of Naples from Ischia to Sorrento and that began with a remarkable water withdrawal of more than 1000 yards followed by waves invading the coasts deep inland. Most cases are small tsunamis observed as anomalous waves on the coasts and causing no victims. This paper is the first systematic attempt to analyse tsunamis generated by volcanic eruptions in Italy and to discuss the tsunamigenic potential of the Italian volcanic sources. Most of the attention is focussed on Vesuvius and the Campanian volcanic area, that will be thoroughly examined. A similarly deep investigation on the Aeolian Islands tsunamis is postponed to a following paper.