INGV reported that at about 1800 on 27 November a vent opened at the NE base of Etna’s SE Crater, at 2,800 m elevation, and produced a lava flow. The flow slowly advanced a few hundred meters towards the Valle del Leone. Tremor levels at the time the vent opened showed no variations from the average trend recorded during the previous week, and no notable changes were identified in deformation data. Effusive activity continued through 30 November, with additional small lava flows emplacing over the first one. For a period of about an hour, beginning at 1700 on 29 November, tremor amplitude increased and then peaked; the amplitude fluctuated between medium and high values for a few hours afterwards. The source of the tremor was in an area between the SE Crater and Bocca Nuova Crater, at elevations of 2,000-2,600 m.

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.

Source: Sezione di Catania - Osservatorio Etneo (INGV)