Report on Bagana (Papua New Guinea) — 17 October-23 October 2007
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 17 October-23 October 2007
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2007. Report on Bagana (Papua New Guinea) (Sennert, S, ed.). Weekly Volcanic Activity Report, 17 October-23 October 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)
During 1-18 October, white vapor plumes from Bagana were occasionally accompanied by ash plumes that were generated by rockfalls from the edges of the lava flow on the SE flank. Incandescence was noted during most of the reporting period at the summit and occasionally from the lava flow. Based on observations of satellite imagery, the Darwin VAAC reported that ash plumes drifted N then NW on 19 October.
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.