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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.

Weekly Report (28 August-3 September 2002)


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 Witori caldera (5.5 x 7.5 km) on the northern coast of central New Britain contains the active Pago cone. The Buru caldera cuts the SW flank. The gently sloping outer flanks consist primarily of dacitic pyroclastic-flow and airfall deposits produced during a series of five major explosive eruptions from about 5,600 to 1,200 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; it has grown to a height above 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.

Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)