Report on Etna (Italy) — 22 November-28 November 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 November-28 November 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 22 November-28 November 2006. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3320 m
All times are local (unless otherwise noted)
INGV reported that a black ash plume from Etna rose above cloud cover to an altitude of 4.8 km (15,700 ft) a.s.l. on 21 November at about 1500. Light ashfall was reported from areas E and NE, including Rifugio Citelli (6 km NE of the SE Crater). After 1900, the cloud cover dissipated and the SE Crater came into view. Strombolian activity generated jets of material greater than 300 m high. Lava flowed down the SSE flanks and continued into 23 November. According to the Toulouse VAAC, mild eruption plumes were visible on an INGV webcam on 24 November. Due to the possible presence of ash plumes, the Fontanarossa airport in E Sicily closed from the evening of 24 November until early 28 November.
Geologic Background. Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km horseshoe-shaped caldera open to the east. Two styles of eruptive activity typically occur, sometimes simultaneously. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more summit craters. Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by Strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank.