INGV reported that activity at Etna’s summit craters continued during 12-18 August. Strombolian activity at Voragine Crater during 12-13 August ejected lava fragments that fell on the cone’s flanks. The seismic network recorded significant increases in tremor levels during 1700-2000 on 14 August and webcam images showed that Strombolian activity at Voragine Crater intensified. The Strombolian activity become lava fountaining by 0030 on 15 August and lava overflowed the W crater rim at Bocca Nuova Crater. Ash plumes at the peak of the activity rose as high as 9.5 km a.s.l. (about 6.2 km above the summit) and drifted SSW and ESE. Tephra fell in several areas including Belpasso, Pedara, Nicolosi, Ragalna, Mascalucia, Tremestieri Etneo, Gravina di Catania, Catania, Viagrande, Milo, Zafferana, Santa Tecla, Giarre, Santa Venerina Aci Bonaccorso, and Syracuse. According to a news article the Aeroporto de Catania (also called the Catania-Fontanarossa Airport) closed due to ashfall on the runways, with flights either being canceled, rescheduled, or diverted to other airports. The lava fountaining began to decrease at around 0230 and ceased at 0320. A two-minute-long explosion was recorded at 0328 and was followed by moderate level of Strombolian activity that gradually decreased. During a field inspection on 15 August scientists observed the new lava flows and noted that they overlapped the 4 August flows and descended farther SW. Lava from the fountaining event continued to fill in Bocca Nuova Crater and partially filled in NE Crater.

Two explosion sequences at Bocca Nuova Crater were recorded at 0430 and 0459 on 18 August and lasted four and six minutes, respectively. The explosions produced eruptive clouds that drifted ENE and rapidly dissipated. The explosions may have reopened the N vent because a thermal anomaly and almost continuous gas emissions from Bocca Nuova followed the events. Strombolian activity at Voragine Crater was also observed on 18 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.

Sources: Sezione di Catania - Osservatorio Etneo (INGV), Euronews