Report on Etna (Italy) — 7 May-13 May 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 7 May-13 May 2008
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2008. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 7 May-13 May 2008. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3295 m
All times are local (unless otherwise noted)
Based on observations using the summit web camera, INGV-CT reported that a week of Strombolian activity from a depression on the E flank of the South East Crater at the summit of Etna ceased on 28 April. On 1 May, a seismic swarm was detected along the NE rift and degassing from the South East Crater and the North East Crater was noted. On 10 May, an eruption produced ash plumes that drifted N; observations were hindered due to cloud cover, but the ash cloud was detected on satellite imagery. Lava flows advanced about 6.4 km E and covered the W wall of the Valle del Bove. Ashfall was reported in multiple areas during 10-11 May.
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.