Report on Manam (Papua New Guinea) — October 1982
Scientific Event Alert Network Bulletin, vol. 7, no. 10 (October 1982)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) Ash emission; weak glow
Please cite this report as:
Global Volcanism Program, 1982. Report on Manam (Papua New Guinea). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 7:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198210-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Little change was noted in the mode of activity in October compared with activity in the second half of September. Both craters continued to produce pale, dark grey and brown ash-laden emissions in moderate quantities. Occasionally, an eruption column 0.5-1 km high was formed. Rumbling sounds were commonly heard coming from the S crater and occasionally from the main crater. The only instances of crater incandescence were observations of weak glow from the S crater on 13 and 14 October.
"Ashfalls were reported from the Sw and E coastal areas, about 5 km from the summit, on about 50% of days. Tiltmeter measurements showed no trends, and seismicity remained at a fairly low level."
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.