Report on Bagana (Papua New Guinea) — October 1985
Scientific Event Alert Network Bulletin, vol. 10, no. 10 (October 1985)
Managing Editor: Lindsay McClelland..
Bagana (Papua New Guinea) Continued mild activity
Please cite this report as:
Global Volcanism Program, 1985. Report on Bagana (Papua New Guinea). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 10:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198510-255020.
Papua New Guinea
6.137°S, 155.196°E; summit elev. 1855 m
All times are local (unless otherwise noted)
"Inspection by Bougainville Island Copper, Ltd. geologists, confirmed the ongoing mild eruptive activity, with extremely slow but sustained progress of the blocky andesite flow active (since ) on the [N and] NW flanks. Weak glow was occasionally observed at night above the summit crater. The viscous lava dome in the crater continued to gently release a faint vapour plume. Seismicity remained weak with a few B-type earthquakes occurring daily."
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.
Information Contacts: C. McKee, RVO.