Report on Manam (Papua New Guinea) — July 1980
Scientific Event Alert Network Bulletin, vol. 5, no. 7 (July 1980)
Managing Editor: David Squires.
Manam (Papua New Guinea) Mild ash emission and occasional rumbling
Please cite this report as:
Global Volcanism Program, 1980. Report on Manam (Papua New Guinea). In: Squires, D (ed.), Scientific Event Alert Network Bulletin, 5:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198007-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Manam's July activity was at a level similar to that of June, although brief periods of stronger seismicity were recorded at the beginning and end of the month. Pale grey/brown or thick white emissions from Southern crater were commonly observed, and blue vapours were occasionally seen. Main crater was often obscured but several observations of pale grey/brown emissions were made. Occasional rumbling sounds were heard, but no crater glows were seen. No trends were registered by the tiltmeters."
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.