Report on Witori (Papua New Guinea) — 4 December-10 December 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 4 December-10 December 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Witori (Papua New Guinea). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 4 December-10 December 2002. Smithsonian Institution and US Geological Survey.
Papua New Guinea
5.576°S, 150.516°E; summit elev. 724 m
All times are local (unless otherwise noted)
An aerial inspection of Pago on 10 December confirmed that lava continued to slowly flow from the volcano. The lava flow remained confined by the walls of Witori caldera. Variable amounts of steam was emitted from vents. Blue vapor, which was inferred to be juvenile volcanic gas, was emitted from the northwestern-most vent. Seismicity continued to be at background levels, and consisted of small volcano-tectonic earthquakes.
Geologic Background. The 5.5 x 7.5 km Witori caldera on the northern coast of central New Britain contains the young historically active cone of Pago. The Buru caldera cuts the SW flank of Witori volcano. The gently sloping outer flanks of Witori volcano consist primarily of dacitic pyroclastic-flow and airfall deposits produced during a series of five major explosive eruptions from about 5600 to 1200 years ago, many of which may have been associated with caldera formation. The post-caldera Pago cone may have formed less than 350 years ago. Pago has grown to a height above that of the Witori caldera rim, and a series of ten dacitic lava flows from it covers much of the caldera floor. The youngest of these was erupted during 2002-2003 from vents extending from the summit nearly to the NW caldera wall.