Report on Etna (Italy) — 22 January-28 January 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 January-28 January 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 22 January-28 January 2020. 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 eruptive activity at Etna’s Voragine Crater (VOR), New Southeast Crater (NSEC), and Northeast Crater (NEC) during 21-26 January. The cone in VOR produced Strombolian explosions which increased in frequency and resulted in rapid cone growth (especially the N part). Lava traveled down the S flank of the cone and into the adjacent Bocca Nuova Crater, filling the E crater (BN-2). Activity at NEC was characterized by discontinuous Strombolian activity and periodic emissions of very diffuse ash plumes. During 21-22 January there were several episodes of ash emissions at NSEC, originating from the vent that had opened on 11 December 2019 on the side of the saddle area. Ash emissions rarely rose form the E vent.
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.