Report on Etna (Italy) — 20 June-26 June 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 June-26 June 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Etna (Italy). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 20 June-26 June 2001. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3320 m
All times are local (unless otherwise noted)
During the week two eruptive episodes occurred at Etna's Southeast Crater. On 22 June an eruption began after 3 days of low activity. The eruption was similar to the previous episodes, with lava flowing down the flanks of the volcano prior to Strombolian activity. Volcanic bombs were thrown 300-400 m above the crater and lava fountains reached a maximum height of 150 m. An ash plume rose up to 3 km above the crater. The Toulouse VAAC reported that the ash plume was visible on Sistema Poseidon's Etna webcam for ~2 hours, but not on satellite imagery. The same day very strong degassing was observed at Bocca Nuova crater. On 24 June another eruptive episode lasted more than 2 hours.
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.