Report on Manam (Papua New Guinea) — September 1984
Scientific Event Alert Network Bulletin, vol. 9, no. 9 (September 1984)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) Ash-laden emissions, incandescence
Please cite this report as:
Global Volcanism Program, 1984. Report on Manam (Papua New Guinea). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 9:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198409-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Following the brief intense eruption of 25 August, activity was steady at a weak-moderate level in September. Both summit craters continued to release ash-laden emissions. Incandescent activity was observed at Southern crater at the beginning and middle of the month, and Main crater incandescence was seen for a few days at mid-month. Seismic amplitudes declined slightly to levels about three times normal. Slight radial inflation of the volcano took place early in the month."
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.