Report on Ulawun (Papua New Guinea) — 23 June-29 June 2010

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 June-29 June 2010
Managing Editor: Sally Kuhn Sennert

Please cite this report as:

Global Volcanism Program, 2010. Report on Ulawun (Papua New Guinea). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 23 June-29 June 2010. Smithsonian Institution and US Geological Survey.

Volcano Profile |  Weekly Report (23 June-29 June 2010)


Papua New Guinea

5.05°S, 151.33°E; summit elev. 2334 m

All times are local (unless otherwise noted)

RVO reported that white-to-gray plumes rose from Ulawun during 23-25 June and fine ash fell on the SW and NW flanks. Low rumbling was heard and dull fluctuating incandescence was observed for a brief period of time from the SE. During 25-26 June white to gray-brown plumes rose 600 m. Seismicity, dominated by volcanic tremor, remained at a moderate level until 26 June, when Real-time Seismic-Amplitude Measurement (RSAM) values declined.

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 north coast of the island of New Britain across a low saddle NE of Bamus volcano, the South Son. The upper 1000 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)