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.
The symmetrical basaltic and andesitic Ulawun stratovolcano is one of Papua New Guinea's most frequently active. Ulawun and Bamus volcano (upper left) are the two highest volcanoes of the Bismarck arc, and are known as the Father and South Son volcanoes, respectively. The upper 1000 m of the 2334-m-high Ulawun is unvegetated. The peak to the left of the summit is a prominent E-W-trending escarpment on the south side that may result from large-scale slumping. Historical eruptions date back to the beginning of the 18th century.
Photo by Wally Johnson (Australia Bureau of Mineral Resources).
Last updated 2023-11-21 23:21:02