Report on Bagana (Papua New Guinea) — April 1986
Scientific Event Alert Network Bulletin, vol. 11, no. 4 (April 1986)
Managing Editor: Lindsay McClelland.
Bagana (Papua New Guinea) Strong plumes; glow; debris slides from lava flow
Please cite this report as:
Global Volcanism Program, 1986. Report on Bagana (Papua New Guinea). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 11:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198604-255020.
Papua New Guinea
6.137°S, 155.196°E; summit elev. 1855 m
All times are local (unless otherwise noted)
"Stronger activity continued in April. On most days, strong white to brown emissions from the summit were reported. Weak crater glow was often observed at night, and on one occasion the upper part of the N flank's active lava flow was also observed to be glowing. Occasional debris slides from the flanks of the lava flow produced impressive ash clouds. Seismicity increased from about 20 B-type events/day in early April to about 50-60 events/day at mid-month, staying at that level for the rest of April."
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. Lowenstein, RVO.