Report on Bagana (Papua New Guinea) — 23 May-29 May 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 May-29 May 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Bagana (Papua New Guinea). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 23 May-29 May 2007. Smithsonian Institution and US Geological Survey.
Papua New Guinea
6.137°S, 155.196°E; summit elev. 1855 m
All times are local (unless otherwise noted)
Based on satellite image observations and information from RVO, the Darwin VAAC reported that a diffuse ash-and-steam plume rose to an altitude of 3.7 km (12,000 ft) a.s.l. on 22 May and drifted W. Another diffuse plume was visible on satellite imagery to an altitude of 3 km (10,000 ft) a.s.l. on 28 May.
Geologic Background. 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.