Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 26 March a low-level ash plume from Bagana drifted 37 km NE. During 27-29 March ash plumes rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 55 km NE and N. On 1 April an ash plume drifted 75 km SE.

Geological Summary. Bagana volcano, occupying a remote portion of central Bougainville Island, is one of Melanesia's youngest and most active volcanoes. This massive symmetrical cone was largely constructed by an accumulation of viscous andesitic lava flows. The entire edifice could have been constructed in about 300 years at its present rate of lava production. Eruptive activity is frequent and characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although explosive activity occasionally producing pyroclastic flows also occurs. Lava flows form dramatic, freshly preserved tongue-shaped lobes up to 50 m thick with prominent levees that descend the flanks on all sides.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)