Report on Ulawun (Papua New Guinea) — December 2017
Bulletin of the Global Volcanism Network, vol. 42, no. 12 (December 2017)
Managing Editor: Edward Venzke. Report research and preparation by: Paul Berger.
Ulawun (Papua New Guinea) Intermittent ash plumes during June-November 2017
Please cite this report as:
Global Volcanism Program, 2017. Report on Ulawun (Papua New Guinea). In: Venzke, E. (ed.), Bulletin of the Global Volcanism Network, 42:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN201712-252120.
Papua New Guinea
5.05°S, 151.33°E; summit elev. 2334 m
All times are local (unless otherwise noted)
Activity at Ulawun has been characterized by intermittent seismic activity and weak ash emissions. The last significant episode was during October-November 2016 (BGVN 41:12). This report summarizes the next eruption, which began on 11 June 2017 and continued sporadically at least through October 2017. Data were provided by the Rabaul Volcano Observatory (RVO) and Darwin Volcanic Ash Advisory Centre (VAAC).
RVO reported that during 1 May-23 June 2017, white plumes rose from Ulawun. Seismicity was low and dominated by small low-frequency earthquakes, although RSAM values slowly increased and then spiked on 13 June. Ash emissions began on 11 June and then became dense during 21-23 June. Volcanic ash advisories from the Darwin VAAC warned of ash plumes from between 24 June and 3 November 2017 (table 5); no further volcanic ash warnings were issued after 3 November. Plumes generally rose to altitudes of 2.4-3 km, or a maximum of 700 m above the summit.
|Dates||Plume altitude (km)||Plume drift|
|24-26 Jun 2017||3||W|
|28 Jun 2017||2.7||W|
|04-08 Aug 2017||2.4-2.7||NW, W, and SW|
|09-10 Aug 2017||2.4||NW, W|
|17-18 Aug 2017||2.7||W|
|31 Aug-01 Sep 2017||2.7||SW, W, NW, and N|
|05 Sep 2017||2.7||SW|
|25 Sep 2017||3||WSW|
|26-27 Oct 2017||2.4||130 km S and SE|
|03 Nov 2017||3||NNE|
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 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: Darwin Volcanic Ash Advisory Centre (VAAC), Bureau of Meteorology, Northern Territory Regional Office, PO Box 40050, Casuarina, NT 0811, Australia (URL: http://www.bom.gov.au/info/vaac/); Rabaul Volcano Observatory (RVO), Geohazards Management Division, Department of Mineral Policy and Geohazards Management (DMPGM), PO Box 3386, Kokopo, East New Britain Province, Papua New Guinea.