Report on Ulawun (Papua New Guinea) — October 1989
Scientific Event Alert Network Bulletin, vol. 14, no. 10 (October 1989)
Managing Editor: Lindsay McClelland.
Ulawun (Papua New Guinea) Weak-moderate vapor emission
Please cite this report as:
Global Volcanism Program, 1989. Report on Ulawun (Papua New Guinea) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 14:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198910-252120
Papua New Guinea
5.05°S, 151.33°E; summit elev. 2334 m
All times are local (unless otherwise noted)
"The low level of activity . . . continued in October. The only visible sign of activity was the steady emission of a weak-moderate white vapour plume from the summit crater. The seismicity has been at background level with <50 small-amplitude B-type events/day."
Geological Summary. 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. The volcano, also known as the Father, rises above the N coast of the island of New Britain across a low saddle NE of Bamus volcano, the South Son. The upper 1,000 m is unvegetated. A prominent E-W escarpment on the south may be the result of large-scale slumping. Satellitic cones occupy the NW and E flanks. A steep-walled valley cuts the NW side, 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: C. McKee, RVO.