HR: 15:00h
AN: V33C-05    [Abstracts]
TI: November 16th 2006 Lateral Collapse of South-East Crater on Mount Etna Volcano and Hazard Implication
AU: * Norini, G
EM: norini@ct.ingv.it
AF: Centro de Geociencias, Campus Juriquilla, UNAM, Apdo. Postal 1-742 Centro, Queretaro, Qro 76001, Mexico
AU: Andronico, D
EM: andronico@ct.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma, 2, Catania, 95123, Italy
AU: De Beni, E
EM: debeni@ct.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma, 2, Catania, 95123, Italy
AU: Polacci, M
EM: polacci@ct.ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma, 2, Catania, 95123, Italy
AU: Grieco, F
EM: cauzmail@gmail.com
AF: CNR - Istituto per la Dinamica dei Processi Ambientali, Sezione di Milano, via Mangiagalli, 34, Milano, 20133, Italy
AB: On November 16th 2006 a sector collapse affected the unstable eastern flank of the South-East Crater (SEC) on Mount Etna Volcano. The SEC is located on the Etna volcano summit and is an active steep cone formed by alternated scoria deposits and lava flows traversed by numerous fractures. The collapse occurred during an eruptive event and was probably triggered by effusive and explosive activity on the SEC. The resulting debris avalanche involved both altered and fresh materials, including an active lava flow. The collapse produced a debris avalanche deposit emplaced on the eastern flank of the volcano, extending up to 1.1 km from the source. The deposit is formed by superimposed flow units, suggesting that it is the result of at least two discrete events, the total volume is estimated in the order of 300,000-500,000 m3. A block-facies and a matrix-facies were recognized in the field. The former is composed by blocks up to 1 meters in dimension and has maximum thickness of 4-5 meters. The matrix-facies is mainly composed by a convection-driven flow deposit consisted of fine ash produced by elutriation during emplacement of the block-facies, maximum observed thickness is 30 cm. The reconstruction of the event has been supported by numerical simulations that were executed using TITAN2D, a modeling software for granular avalanches and landslides developed by GMFG at Buffalo. This approach is also useful to estimate the area that would be affected by an eventual similar event that could interest the SEC. The area affected by the lateral collapse of the SEC is a small portion of the summit area of Mount Etna, but the fact that no one was killed or injured should be considered fortuitous. This because the summit and adjacent areas of the volcano are usually visited by several people, especially tourists, not prepared to face this type of events, which was never observed and described during the recent activity of Mount Etna. The collapse of November 16th 2006 underscores the need to prepare for similar events through scientific investigation (analysis of instability, numerical modelling of flows) and development of specific civil protection plans.
DE: 8404 Volcanoclastic deposits
DE: 8414 Eruption mechanisms and flow emplacement
DE: 8488 Volcanic hazards and risks
SC: Volcanology, Geochemistry, and Petrology [V]
MN: 2007 Joint Assembly