The Darwin VAAC reported that ash plumes from Bagana were visible in satellite images rising to 2.1 km (7,000 ft) a.s.l. at 0800 on 12 August and 3 km (10,000 ft) a.s.l. a few hours later at 1220; the plumes drifted NW and W, respectively. According to a news report aid has been sent to the more than 6,300 people that have been adversely affected by the recent explosive eruptions at Bagana. The report noted that as many as 17,000 residents living near the volcano may be impacted.

Geological Summary. Bagana volcano, in a remote portion of central Bougainville Island, is frequently active. 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 characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although occasional explosive activity produces pyroclastic flows. Lava flows with tongue-shaped lobes up to 50 m thick and prominent levees descend the flanks on all sides.

Sources: Darwin Volcanic Ash Advisory Centre (VAAC), US Agency for International Development / Bureau for Humanitarian Assistance