Report on Etna (Italy) — 24 February-2 March 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
24 February-2 March 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 24 February-2 March 2021. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3320 m
All times are local (unless otherwise noted)
INGV reported continuing episodes of lava fountaining at Etna’s Southeast Crater (SEC) and 24 and 28 February. Strombolian activity at two vents in SEC increased during the late afternoon of 24 February. Lava overflowed the crater at 1820 and headed ESE towards the Valle de Bove. During 1900-2122 lava fountains rose as high as 500 m above the summit. A second lava flow traveled SW, and at 2100 a pyroclastic flow descended 1 km into the Valle de Bove. An eruption plume rose as high as 11 km a.s.l.
Weak Strombolian activity was visible at 0810 on 28 February. Lava fountaining began at 0839, feeding lava flows that traveled E, and abruptly intensified at 0902 with jets of lava rising 700 m above the crater rim. An eruption plume rose as high as 11 km a.s.l. and drifted ESE, causing ashfall in areas downwind. A small lava overflow at the S part of SEC began at 0909, followed by a pyroclastic flow at 0920. Lava fountaining ended at 0933, though the lava flow descending E remained active.
Geological Summary. 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.