Report on Manam (Papua New Guinea) — December 1978
Scientific Event Alert Network Bulletin, vol. 3, no. 12 (December 1978)
Managing Editor: David Squires.
Manam (Papua New Guinea) Ash emission more frequent; glow often visible
Please cite this report as:
Global Volcanism Program, 1978. Report on Manam (Papua New Guinea) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 3:12. Smithsonian Institution.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
Intermittent ash emission from Southern crater was less frequent in November and early December than in October. Ejection of incandescent lava fragments was seen on seven nights in November and glow was observed on seven nights in mid-December. For most of the second half of December, white and occasionally blue vapor issued from Southern crater. Ash ejection from Main crater was reported on 9, 13, 22, and 29 November, and on 6 December. Glow was seen over Main crater on 11 November, and 17, 21, and 23 December.
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.