Report on Etna (Italy) — 18 June-24 June 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 18 June-24 June 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Etna (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 18 June-24 June 2014. 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 weak Strombolian activity at Etna's New Southeast Crater (NSEC) continued through 10 June. Some explosions ejected incandescent pyroclastic material a few tens of meters above the crater rim that occasionally fell onto the outer flanks.
On 14 June a new eruptive episode began within the NSEC, beginning with near-continuous Strombolian explosions and lava fountaining. Fine ash emissions were concurrent with lava that began to overflow the edge of the SE crater, forming a flow that continued downhill on the W wall of Valle del Bove. During the morning of 15 June the overflowing lava followed the fissure that had been formed on 28 November 2013. A spatter cone also formed in the E sector of the cone. During 14-15 June volcanic tremor increased sharply and remained at a medium-high level until 18 June when it returned to normal levels.
INGV noted that this activity was similar to the episode of effusive lava emissions observed during 14-16 and 19-31 December 2013 in terms of duration and intensity.
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.