Report on Etna (Italy) — 5 February-11 February 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 February-11 February 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 February-11 February 2014. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3295 m
All times are local (unless otherwise noted)
INGV reported that during 4-5 February activity at Etna's New Southeast Crater (NSEC) was characterized by intermittent ash emissions accompanied by jets of incandescent pyroclastic material, and a constant emission of lava from one or two vents at the E base of the NSEC cone. The lava flows reached the base of the W slope of the Valle del Bove. On 6 February ash emissions ceased and small Strombolian explosions ejected incandescent pyroclastic material 100 m above the crater. On 7 February Strombolian explosions ejected material onto the flanks of the cone, and the next day ash puffs were observed. During 9-11 February activity continued to be characterized by Strombolian activity, periodic ash emissions, and advancing lava flows. At 0707 on 11 February a large quantity of reddish brown ash emitted from an area near the vents formed a very dense hot flow which quickly reached the base of the W wall of the Valle del Bove. Reddish brown ash emissions continued after the event.
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.