Report on Etna (Italy) — 30 April-6 May 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 30 April-6 May 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, 30 April-6 May 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 the morning of 22 April sporadic and weak Strombolian activity resumed at Etna's New Southeast Crater (NSEC) and continued for the next few days. Some explosions ejected incandescent pyroclastic material out of the crater and onto the upper S and SE flanks of the cone. A few small collapses occurred on the cone's unstable E flank. The frequency and intensity of Strombolian explosions slightly increased late in the evening on 30 April. Degassing at the Northeast Crater also increased and thermal anomalies were detected by a camera.
Weak Strombolian activity continued to be detected through 1 May. During the night of 2-3 May incandescence was caused by weak high-temperature gas emissions and/or Strombolian explosions. The activity intensified on 4 May and some of the explosions ejected incandescent pyroclastic material onto the high S and SE parts of the NSEC cone.
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.