Report on Bagana (Papua New Guinea) — 22 August-28 August 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 August-28 August 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, 22 August-28 August 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)
RVO reported that an effusive lava flow from Bagana's summit crater began travelling down the SE flank on 6 August and continued flowing through 23 August. Continuous incandescence was visible down the SE flank during 6-10 August. During 6-23 August, white vapor plumes were occasionally accompanied by ash plumes that were generated by rockfalls from lava-flow edges. Based on satellite imagery, the Darwin VAAC reported that a diffuse plume rose to an altitude of 3.7 km (12,000 ft) a.s.l. on 23 August.
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.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Rabaul Volcano Observatory (RVO)