The Sezione di Catania - Osservatorio Etneo (INGV) reported that an eruption at Etna continued during 17-23 February. Activity observed through webcams and during field inspections on 19, 22, and 24 February was characterized by the effusion of a lava flow from a fissure, explosive activity at the summit, and gas emissions at several of the craters. Strombolian activity at SE Crater was variable, though no explosions were visible during 20-21 February and for most of 22 February. The explosions produced minor ash plumes that dispersed near the summit. Sporadic and moderate explosions from three vents were visible during the evening of 22 February. The activity slightly intensified during 23 February and into 24 February; during the morning of 24 February a fourth explosive vent was identified and at about 1323 a lava flow overflowed the S rim of the crater.

The lava flow from the fissure that opened at the base of Bocca Nuova Crater on 8 February continued to effuse lava. The lava flow advanced down the SW flank, descending to 1,840 m elevation during 19-20 February; lava-flow activity was confined to an area between about 3,000 and 2,500 m elevation during the rest of the week. The total flow length was 4.3 km. Based on a 24 February field inspection, scientists determined that lava effusion was occurring at the main vent and also emerging from lava tubes at lower elevations. Lava flows branched from the main flow, widening the flow field, especially near the vent. They also observed a small lava flow effusing from a new vent about 150 m higher up the flank at about 3,070 m elevation.

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)