Report on Ulawun (Papua New Guinea) — December 1982
Scientific Event Alert Network Bulletin, vol. 7, no. 12 (December 1982)
Managing Editor: Lindsay McClelland
Ulawun (Papua New Guinea) Vapor emission for three days
Please cite this report as:
Global Volcanism Program, 1982. Report on Ulawun (Papua New Guinea). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 7:12. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198212-252120.
Papua New Guinea
5.05°S, 151.33°E; summit elev. 2334 m
All times are local (unless otherwise noted)
"A very large white vapour cloud was emitted from the summit for several hours during the morning of 24 December, and moderate to strong vapour emission continued for three days. This coincided with a decline in seismicity which had been at a higher than usual level since mid-November. During the last week of the month seismic activity remained below the usual level of 1,000 to 1,500 B-type events per day. The vapour emission on the 24th is the most visible sign of activity since the volcano last erupted in October 1980 (05:10)."
Geologic Background. The symmetrical basaltic-to-andesitic Ulawun stratovolcano is the highest volcano of the Bismarck arc, and one of Papua New Guinea's most frequently active. Ulawun volcano, also known as the Father, rises above the north coast of the island of New Britain across a low saddle NE of Bamus volcano, the South Son. The upper 1000 m of the 2334-m-high Ulawun volcano is unvegetated. A prominent E-W-trending escarpment on the south may be the result of large-scale slumping. Satellitic cones occupy the NW and eastern flanks. A steep-walled valley cuts the NW side of Ulawun volcano, and a flank lava-flow complex lies to the south of this valley. Historical eruptions date back to the beginning of the 18th century. Twentieth-century eruptions were mildly explosive until 1967, but after 1970 several larger eruptions produced lava flows and basaltic pyroclastic flows, greatly modifying the summit crater.
Information Contacts: P. de Saint Ours and P. Lowenstein, RVO.