Report on Ulawun (Papua New Guinea) — 17 August-23 August 2005

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 August-23 August 2005
Managing Editor: Gari Mayberry

Please cite this report as:

Global Volcanism Program, 2005. Report on Ulawun (Papua New Guinea). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 17 August-23 August 2005. Smithsonian Institution and US Geological Survey.

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Ulawun

Papua New Guinea

5.05°S, 151.33°E; summit elev. 2334 m

All times are local (unless otherwise noted)


Volcanic activity remained at low levels at Ulawun during 15-21 August, with steam emitted from the summit crater. Seismicity was at low levels, consisting of small low-frequency earthquakes.

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.

Source: Rabaul Volcano Observatory (RVO) via the Darwin Volcanic Ash Advisory Center