Report on Manam (Papua New Guinea) — October 1979
Scientific Event Alert Network Bulletin, vol. 4, no. 10 (October 1979)
Managing Editor: David Squires.
Manam (Papua New Guinea) Ash emission and glow
Please cite this report as:
Global Volcanism Program, 1979. Report on Manam (Papua New Guinea) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 4:10. Smithsonian Institution.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"During the reporting period 12-22 October, white vapour was emitted from both Main and Southern craters. Additionally, Main crater released grey ash on 13 October and brown ash 16-18 October. Glow was seen from both vents on most nights during the reporting period, and sparse lava ejections from the Southern crater were seen on the 16th. Roaring and rumbling noises were heard 13-15 October. There appeared to be no trend in tilt, and seismic activity remained steady at the same level as in September. Reports from Manam have been interrupted by the breakdown of Tabele Observatory's electrical generators.
"A brief aerial inspection on 26 October revealed that only thick white vapour emission was occurring at both vents. No clear views into the Southern crater were obtained, but a dark surface of lava (fragments?) was seen in Main crater."
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.