Report on Etna (Italy) — 27 June-3 July 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 27 June-3 July 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, 27 June-3 July 2001. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3295 m
All times are local (unless otherwise noted)
An eruptive episode began on the evening of 27 June at the NNE vent on Southeast Crater. The episode began with lava flowing from the NNE vent and was followed by Strombolian activity at the NNE vent and the summit. Volcanic material was ejected to a maximum height of 400 m. No sustained lava fountains developed. The Toulouse VAAC reported that Sistema Poseidon's Etna webcam recorded renewed volcanic activity on 28 June at 0030 and associated steam and ash that did not rise far above the summit. The eleventh eruptive episode in one month began on 30 June. Inclement weather inhibited visual observations, but during a break in cloud cover around 0400 mild Strombolian activity was observed. Seismic data revealed that the episode ended around 1600. On 3 July increased degassing was observed at Northeast Crater.
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.