Report on Manam (Papua New Guinea) — September 1978
Scientific Event Alert Network Bulletin, vol. 3, no. 9 (September 1978)
Managing Editor: David Squires.
Manam (Papua New Guinea) Occasional minor ash ejection continues
Please cite this report as:
Global Volcanism Program, 1978. Report on Manam (Papua New Guinea) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 3:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197809-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
Minor ash ejection from Southern crater has been reported at intervals since mid-March: on 8 and 19-20 June; 11-13, 16-17, 19, and 27 July; 24, 26-28, and 31 August; and 2, 8-11, 14-16, and 18-22 September. Ashfall has been noted a number of times, particularly since mid-September.
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: R. Cooke, RVO.