Report on Manam (Papua New Guinea) — January 1981
Scientific Event Alert Network Bulletin, vol. 6, no. 1 (January 1981)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) South vent glows, emits ash
Please cite this report as:
Global Volcanism Program, 1981. Report on Manam (Papua New Guinea). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 6:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198101-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Moderate to strong light brown to grey ash-laden vapour and, rarely, dark brown dust were sporadically ejected from Southern crater. Main crater occasionally emitted weak white vapour. Light ashfall from Southern crater was recorded at nearby Tabele on 2 December. Low rumbling noises were heard on 20 and 25 December. A weak glow from Southern crater was observed at night 26-29 December. Seismic activity was at its normal level. [Tilt measurements indicated radial inflation of about 3 µrad in December. This followed a net inflationary radial tilt of about 2 µrad in October.]"
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: B. Talai and P. Lowenstein, RVO.