Report on Manam (Papua New Guinea) — February 1992
Bulletin of the Global Volcanism Network, vol. 17, no. 2 (February 1992)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) Ash emission; seismicity remains low
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, 17:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199202-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Activity at Manam's Southern Crater was at a low-moderate level during February with a slight increase at the end of the month. Southern Crater emissions consisted of weak pale-grey or pale-brown vapour and ash clouds. On a few days the ash content of the emissions was markedly higher, leading to ashfalls in coastal areas (4-5 km from the summit). In general, the emissions occurred without significant sound effects, although rumbling was heard on 29 February in association with thick, dark ash clouds, night glow, and incandescent lava ejections. No activity was observed from Main Crater. Seismicity fluctuated a little but remained at a low level with daily counts of low-frequency events ranging from 100 to 350."
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: C. McKee, RVO.