Report on Etna (Italy) — 26 April-2 May 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
26 April-2 May 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 26 April-2 May 2017. Smithsonian Institution and US Geological Survey.
37.748°N, 14.999°E; summit elev. 3357 m
All times are local (unless otherwise noted)
INGV reported that at 1820 on 26 April lava began effusing from a vent on the S side of Etna's New Southeast Crater (NSEC), traveling to the base of the cone. Around 2220 Strombolian activity ejected material from the vent and the lava flow headed towards the Valle del Bove. A lava flow on the N side of the cone began at 0220 on 27 April and traveled NE towards the Valle del Leone. Ash emissions were visible at 0320. Strombolian activity began to diminish around 1230 and eventually ceased. The lava flows advanced until around 1600; phreato-magmatic explosions occurred in areas where the NE flow interacted with snow.
Geological Summary. Mount Etna, towering above Catania on the island of Sicily, has one of the world's longest documented records of 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 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.