Report on Bagana (Papua New Guinea) — December 1987
Scientific Event Alert Network Bulletin, vol. 12, no. 12 (December 1987)
Managing Editor: Lindsay McClelland.
Bagana (Papua New Guinea) Strong steam emissions; low seismicity
Please cite this report as:
Global Volcanism Program, 1987. Report on Bagana (Papua New Guinea). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 12:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198712-255020.
Papua New Guinea
6.137°S, 155.196°E; summit elev. 1855 m
All times are local (unless otherwise noted)
The summit was often obscured in December, but when visible at mid-month strong white emissions were observed. Seismicity was at a low level of about 10 volcanic earthquakes/day with a recorded maximum of 30/day on 9 December; the seismograph was not operating for part of the month.
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 and P. Lowenstein, RVO.