Report on Ulawun (Papua New Guinea) — November 1984
Scientific Event Alert Network Bulletin, vol. 9, no. 11 (November 1984)
Managing Editor: Lindsay McClelland.
Ulawun (Papua New Guinea) Seismicity increases; vapor emission
Please cite this report as:
Global Volcanism Program, 1984. Report on Ulawun (Papua New Guinea) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 9:11. Smithsonian Institution.
Papua New Guinea
5.05°S, 151.33°E; summit elev. 2334 m
All times are local (unless otherwise noted)
"No further eruptive activity has occurred since the short-lived Strombolian eruption, 4-11 September. The only visible activity has been moderate emissions of white vapours. However, volcano seismicity started to increase again on 9 November. Beginning 14 November, daily totals of B-type events averaged about 600, a marked increase from daily totals that usually numbered less than 50, 14 September-8 November. The amplitudes of these events also increased substantially."
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. 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.