Report on Manam (Papua New Guinea) — January 1992
Bulletin of the Global Volcanism Network, vol. 17, no. 1 (January 1992)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) Ash ejection; incandescent tephra
Please cite this report as:
Global Volcanism Program, 1992. Report on Manam (Papua New Guinea). In: McClelland, L. (ed.), Bulletin of the Global Volcanism Network, 17:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199201-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"There was a slight increase in activity at Manam's Southern Crater during mid-January. Bad weather conditions prevented observation of the summit until 11 January. Southern Crater emitted thin to thick grey and brown ash clouds on 12-21 and 30 January. The emissions resulted in fine ashfall on the SE side of the island and were accompanied by occasional weak roaring and rumbling noises. For the first time since mid-October 1991, weak fluctuating glow and projection of incandescent lava fragments (to 80-120 m above the crater rim) were seen on 30 January. Some of the incandescent lava fragments rolled down the SE valley. Activity from Main Crater remained at a very low level throughout January, consisting of gentle emissions of thin white vapor. Seismic recording resumed on 23 January, ending 2 1/2 months of instrumental problems. Seismic activity was at a low-moderate level with daily counts of low-frequency events ranging from 100 to 500."
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.
Information Contacts: H. Patia, P. de Saint-Ours, and B. Talai, RVO.