INGV reported that Strombolian activity at Etna’s SE Crater (SEC) was periodically visible during 20-26 November; weather clouds often prevented visual observations. The frequency of the eruptive activity was on the scale of hours, and explosions were most intense during 25-26 November. The explosions ejected material that fell within the crater or nearby on the flanks and produced ash emissions that rapidly dispersed near the summit. Lava overflowed the crater starting at 1810 on 24 November and produced a slow-moving lava flow that descended the S flank to the base of the cone. The lava flowed down the same ravine as one of the three flows emplaced on 12 November and was no longer being fed by 0450 on 25 November. During periods of more intense Strombolian activity on 26 November ejected lava that accumulated on the upper S flank and was visible in thermal webcam images. Activity at Bocca Nuova Crater was characterized by pulsating gas emissions and flashes of incandescence generated by the hot gases.

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)