Report on Ulawun (Papua New Guinea) — March 1993
Bulletin of the Global Volcanism Network, vol. 18, no. 3 (March 1993)
Managing Editor: Edward Venzke
Ulawun (Papua New Guinea) Activity continues at low level
Please cite this report as:
Global Volcanism Program, 1993. Report on Ulawun (Papua New Guinea). In: Venzke, E (ed.), Bulletin of the Global Volcanism Network, 18:3. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.BGVN199303-252120.
Papua New Guinea
5.05°S, 151.33°E; summit elev. 2334 m
All times are local (unless otherwise noted)
"Activity . . . continued at the low levels reported for February. White vapour emissions usually varied from weak to moderate but were more forceful 26-27 March. Weak glow was reported on the 8th.
"Seismic activity was at a low level throughout the month; no distinct B-type earthquakes were recorded. Both RSAM and routine manual amplitude readings indicate a gradual decline in tremor levels since mid-February. However, the level of tremor is still higher than before January's brief flurry of activity."
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: H. Patia, R. Stewart, and C. McKee, RVO.