Report on Etna (Italy) — 23 October-29 October 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 October-29 October 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 23 October-29 October 2013. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3295 m
All times are local (unless otherwise noted)
Sezione di Catania - Osservatorio Etneo reported that on 26 October Etna's New Southeast Crater (NSEC) produced a new episode of lava fountaining, six months after the previous paroxysm. A gas plume laden with pyroclastic material rose several kilometers above the summit and drifted SW, affecting population centers as far as the Caltanissetta area. According to a news article a representative from Catania airport noted that the eruption caused the closure of nearby airspace before dawn through the early morning.
Lava emitted from the saddle between the two cones of the Southeast Crater advanced S, destroying two wooden shacks at Torre del Filosofo. Another smaller lava flow descended the SE flank of the NSEC cone, partially filling the deep collapse scar formed during the 27 April 2013 paroxysm. At 1019 vigorous ash emissions from the Northeast Crater formed a dark brown plume that rose 1 km; ash emissions from that crater continued through late evening. Lava fountaining from NSEC continued through the late morning and was then followed by a long series of powerful explosions audible to many tens of kilometers away. Strombolian explosions occurred in the late evening. Lava flows continued to advance the next day.
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.