Report on Bagana (Papua New Guinea) — January 1992
Bulletin of the Global Volcanism Network, vol. 17, no. 1 (January 1992)
Managing Editor: Lindsay McClelland.
Bagana (Papua New Guinea) Continued extrusion of viscous lava; occasional dome collapse episodes
Please cite this report as:
Global Volcanism Program, 1992. Report on Bagana (Papua New Guinea). In: McClelland, L. (ed.), Bulletin of the Global Volcanism Network, 17:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199201-255020.
Papua New Guinea
6.137°S, 155.196°E; summit elev. 1855 m
All times are local (unless otherwise noted)
"Socio-political unrest on Bougainville Island Island has prevented transmission of any reports of Bagana's activity since late July 1990. However, Bagana's former observer recently arrived in Rabaul and confirmed that the volcano has remained active, with slow, continuous extrusion of sluggish lava into the summit crater and onto the volcano's flanks. A significant change occurred on the night of 14 January 1991, when part of the summit lava dome collapsed onto the SE flank of the volcano, and initiated a new lava channel between the 1966-75 and 1987-90 lava flows. Apparently, the blocky lava flow is slowly advancing in the saddle between Bagana and the nearby Pleistocene Reini Volcano. Other minor collapses of the summit dome occurred occasionally onto the SW flank (and possibly other parts of the volcano). The current activity is apparently similar to that reported up to mid-1990, with release of a brownish white plume from the dome, extremely slow extrusion of lava, and frequent tumbling of rocks down the flanks of the volcano."
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: H. Patia, P. de Saint-Ours, and B. Talai, RVO.