Report on Etna (Italy) — 22 January-28 January 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 January-28 January 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, 22 January-28 January 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 during 4-13 January nearly continuous emissions of reddish ash from Etna's Northeast Crater were visible. Strong degassing continued at least through 22 January. Strombolian activity at New Southeast Crater (NSEC) began on the evening of 21 January, following 20 days of quiet. Some explosions generated very small ash emissions that barely rose above the crater rim. Late on 22 January a small lava flow from the vent on the high E flank of the NSEC cone traveled a few hundred meters in a few hours. Strombolian explosions ejected incandescent pyroclastic material onto the cone flanks. The frequency and intensity of the explosions decreased early on 23 January, and the lava flow stopped advancing. At 0105 a small puff of gas and/or ash from the E base of the cone heralded a new lava flow that traveled W towards the Valle del Bove. Weak Strombolian activity and the advancing lava flow continued during 24-28 January, although on 25 January the amount of ash produced by the Strombolian activity increased. On 26 January an ash plume drifted E. By evening the intensity of the Strombolian activity as well as the amount of ash in the emissions decreased. The lava flow was 4 km long.
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.