"No further eruptive activity has occurred since the short-lived Strombolian eruption, 4-11 September. The only visible activity has been moderate emissions of white vapours. However, volcano seismicity started to increase again on 9 November. Beginning 14 November, daily totals of B-type events averaged about 600, a marked increase from daily totals that usually numbered less than 50, 14 September-8 November. The amplitudes of these events also increased substantially."

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.

Information Contacts: C. McKee, RVO.