Report on Manam (Papua New Guinea) — 17 November-23 November 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 November-23 November 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Manam (Papua New Guinea). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 17 November-23 November 2004. 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 17-23 November, the Darwin VAAC issued numerous volcanic ash advisories concerning plumes emitted from Manam that were visible on satellite imagery. On 19 November at 1125, a plume visible on satellite imagery reached a height of 7-8 km a.s.l and extended 74 km to the NE. A plume detected on 23 November at 2225 rose to around 14 km a.s.l and extended 130 km to the ESE. The Aviation Color Code was at Red, the highest level. Rabaul Volcanological Observatory advised that the eruptions of Manam are continuing with occasional stronger activity.
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)