Report on Witori (Papua New Guinea) — 28 August-3 September 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
28 August-3 September 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, 28 August-3 September 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)
The Japanese Disaster Relief Team that visited Pago during 25 August to 3 September found that lava had erupted from four of the five craters NW of the Pago Central cone that are aligned NW-SE. The largest quantity of lava was emitted from the lowest cone; lava from the cone flowed NE and then was directed SE after reaching the crater wall. Two faults were visible; one was parallel to the crater line, and the other was perpendicular to it. No eruption column was observed, only blue-white fumarolic gas was emitted. The thickest ash deposits were 2 mm thick 3 km N of the craters, and less than 1 mm thick at Hoskins airport.
Geological Summary. 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.