Report on Bagana (Papua New Guinea) — 20 August-26 August 2025
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 20 August-26 August 2025
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2025. Report on Bagana (Papua New Guinea) (Sennert, S, ed.). Weekly Volcanic Activity Report, 20 August-26 August 2025. Smithsonian Institution and US Geological Survey.
Bagana
Papua New Guinea
6.137°S, 155.196°E; summit elev. 1855 m
All times are local (unless otherwise noted)
The Darwin Volcanic Ash Advisory Centre (VAAC) reported that an ash plume from Bagana was identified in satellite images rising to 2.1 km (7,000 ft) a.s.l. and drifting NW at 0820 on 25 August.
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.
