Report on Ulawun (Papua New Guinea) — 26 September-2 October 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
26 September-2 October 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Ulawun (Papua New Guinea). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 26 September-2 October 2001. Smithsonian Institution and US Geological Survey.
Papua New Guinea
5.05°S, 151.33°E; summit elev. 2334 m
All times are local (unless otherwise noted)
Volcanic tremor occurred at Ulawun on 24 September at 2200 through 30 September. After the tremor peaked on the 27th at about 1000 it fluctuated as it generally declined. By 30 September seismic activity was at moderate levels. During 27-30 September a very slow deflationary trend was detected.
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.
Source: Rabaul Volcano Observatory (RVO)