Report on Etna (Italy) — 23 June-29 June 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
23 June-29 June 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, 23 June-29 June 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 that there were nine episodes of lava fountaining at Etna’s Southeast Crater (SEC) during 21-27 June. The episodes were recorded shortly after midnight on 21 June, at dawn on 22 June, at dawn and sunset on 23 June, in the late morning on 24 June, at dawn and sunset on 25 June, in the afternoon on 26 June, and during the late morning of 27 June. Explosive activity was concentrated in the W part of SEC at three of the four saddle vents; some weak explosions occurred at the E vents. The episodes produced ash plumes that rose 5-10 km (16,400-32,800 ft) a.s.l. and lava flows that traveled SW and SE. Lava also began to effuse on 23 June from the vent on the SE flank of the SEC cone. INGV noted that these continuing episodes have caused the SEC cone to grow significantly, especially compared to the previous year, changing not only it’s morphology but the whole profile of Etna as well.
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.