Report on Etna (Italy) — 9 May-15 May 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 9 May-15 May 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, 9 May-15 May 2001. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3320 m
All times are local (unless otherwise noted)
The Italy's Volcanoes website reported that after more than 8 months of minor activity (slow lava flows, degassing, light ash emission, and low-level Strombolian activity), a new episode of vigorous volcanic activity began at Southeast Crater on 9 May. On 6 May active lava flows and explosions were observed launching pyroclasts and lithics onto the volcano's S flank every 7-10 seconds. On 9 May an obvious increase in activity occurred, with Strombolian bursts occurring every few seconds. By 1745 activity further increased and lava fountains rose up to 100 m above the NNE flank fissure while a dense eruption cloud simultaneously rose above the summit vent. Local press sources reported that air traffic was rerouted during the activity. The high level of activity continued at Southeast Crater through at least 14 May and strong degassing occurred at Bocca Nuova 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.