Report on Etna (Italy) — 27 November-3 December 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 27 November-3 December 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 27 November-3 December 2019. 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 eruptive activity at Etna’s summit craters continued during 25 November-1 December. Strombolian explosions at Voragine Crater (VOR) occurred at intervals of 5-10 minutes, and many incandescent jets rose above the crater rim. Some explosions created incandescent flashes in emissions rising above the crater rim. A cone which had started forming on the crater floor in mid-September had continued to grow according to observations by field guides. Sporadic ash emissions began at New Southeast Crater (NSEC) on the evening of 30 November, and a single Strombolian explosion was recorded on 1 December. Incandescence from Bocca Nuova Crater was intermittently visible at night.
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.