Report on Etna (Italy) — 29 May-4 June 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 May-4 June 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, 29 May-4 June 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 at 0220 on 30 May a fissure opened at the N base of Etna’s NSEC at about 3,150 m elevation. The fissure produced Strombolian explosions and a lava flow that advanced towards the W wall of the Valle del Bove; by 0915 it had reached 2,050 m elevation near Monte Simone. The flow was 2 km in length. Two fissures opened a few hours later at the SE base of NSEC at an elevation of about 3,050 m, each producing lava flows that converged and traveled along the W wall of the Valle del Bove towards Serra Giannicola Grande, partially covering the 2018 lava flows. The flow reached 2,260 m elevation by 0915. The fissure activity was accompanied by ash emissions which were intense starting at 1150 but then decreased and almost stopped late in the evening. The lava flow reached the bottom of the valley in the early hours of 31 May and had a length of about 3 km.
INGV volcanologists confirmed that lava continued to effuse from both fissures during a visual inspection in the morning of 1 June and that vigorous spatter was occurring at a fissure on the SE base of NSEC. By 1930 the lava flow from the N base was no longer being fed and was cooling. During a visual inspection of the eruption site on 2 June volcanologists confirmed explosive activity at a fissure segment at 2,850 m and continuing lava effusion. The lava traveled along the W wall of the Valle del Bove, overlapping flows from previous days.
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.