Report on Bagana (Papua New Guinea) — May 1990
Bulletin of the Global Volcanism Network, vol. 15, no. 5 (May 1990)
Managing Editor: Lindsay McClelland.
Bagana (Papua New Guinea) Frequent ash emissions, rumbling
Please cite this report as:
Global Volcanism Program, 1990. Report on Bagana (Papua New Guinea). In: McClelland, L. (ed.), Bulletin of the Global Volcanism Network, 15:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199005-255020.
Papua New Guinea
6.137°S, 155.196°E; summit elev. 1855 m
All times are local (unless otherwise noted)
"Bagana was at a fairly high level of activity throughout May. On most days, thick white or grey clouds were emitted from the summit area and loud rumbling noises were heard. On the 6th, 8th, 20th, 21st, 23rd, and 26th, 1-3 explosions produced dark ash-laden columns to 2 km above the summit. Weak red glow was observed on most nights during the last 3 weeks of the month.
"The blocky lava flow being slowly extruded from the summit crater was seen to overflow on several days onto the upper E, SE, and SW flanks. Small to moderate rockfalls were reported daily on the E and S sides 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: P. de Saint-Ours and C. McKee, RVO.