INGV reported that during 27 July-9 August activity at Etna was characterized by intra-crater Strombolian activity at Northeast Crater (NEC), sporadic Strombolian activity at Voragine Crater (VOR) with minor ash emissions that quickly dispersed, and both Strombolian activity and diffuse ash emissions at the New Southeast Crater (NSEC) cone. Explosive activity increased on 31 July; an ash cloud rose to 4.5 km (14,800 ft) a.s.l. On 2 August very minor ashfall was reported in Trecastagni and Acicastello, possibly from a slight increase in explosive activity that was not visually confirmed.

During 3-9 August Strombolian activity ejected material above the NSEC cone’s crater rim; the activity was almost continuous during the evening of 6 August and the next morning, and booming was heard several kilometers away. Ash emissions dispersed near the summit. A series of ash emissions were visible in the morning of 9 August.

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)