Report on Manam (Papua New Guinea) — 23 August-29 August 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 August-29 August 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Manam (Papua New Guinea). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 23 August-29 August 2006. Smithsonian Institution and US Geological Survey.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
During 22-23 August, emissions from Manam consisted of dark brown-to-gray ash plumes that rose 1-2 km above the summit (9,200-12,500 ft a.s.l.) and drifted W and NW.
The Darwin VAAC reported that eruption plumes were visible on satellite imagery on 23 and 26 August, extending NW. Ash was not identified in the imagery.
Geologic Background. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys" channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Rabaul Volcano Observatory (RVO)