The 16 November 2006 flank collapse of South-East Crater at Mount Etna, Italy: study of the deposit and hazard assessment

Abstract

On 16 November 2006 a flank collapse affected the unstable Eastern slope of the South-East Crater 16 (SEC) of Mt. Etna. The collapse occurred during one of the paroxysmal events with sustained strombolian 17 activity that characterized the August-December 2006 eruption and was triggered by erosion of loose, 18 hydrothermally-altered material of the steep south-east sector of SEC from the outpour of lava. The collapse 19 produced a debris avalanche that involved both lithic and juvenile material and resulted in a deposit 20 emplaced on the Eastern flank of the volcano up to 1.2 km away from the source. The total volume of the 21 deposit was estimated to be in the order of 330,000-413,000 m3. The reconstruction of the collapse event 22 was simulated using TITAN2D, software designed to model granular avalanches and landslides. This 23 approach can be used to estimate areas that may be affected by similar collapse events in the future. The 24 area affected by the 16 November 2006 lateral collapse of SEC was a small portion of the Mt. Etna summit 25 area, but the fact that no one was killed or injured should be considered fortuitous. The summit and adjacent 26 areas of the volcano, in fact, are usually visited by many tourists who are not prepared to face this type of 27 danger. The 16 November 2006 collapse points to the need to be prepared for similar events through 28 scientific investigation (analysis of flank instability, numerical simulation of flows) and development of specific civil protection plans