Report on Ulawun (Papua New Guinea) — June 1995
Bulletin of the Global Volcanism Network, vol. 20, no. 6 (June 1995)
Managing Editor: Richard Wunderman.
Ulawun (Papua New Guinea) Variable vapor emissions
Please cite this report as:
Global Volcanism Program, 1995. Report on Ulawun (Papua New Guinea). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 20:6. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.BGVN199506-252120.
Papua New Guinea
5.05°S, 151.33°E; summit elev. 2334 m
All times are local (unless otherwise noted)
Activity throughout April-June continued at a low level. During April and May, emissions consisted of weak to strong white vapor, with occasional gray emissions during May. Ulawun released mostly weak to moderate white vapor, occasionally high in volume during June. On 2 June low volumes of blue vapor accompanied the white vapor. Neither audible noises nor summit glow were noted. Throughout April the seismograph was not operational. Seismicity was at a low level between 16 and 27 May, after which time none was recorded.
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-trending 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: Ima Itikarai and Ben Talai, RVO.