Report on Manam (Papua New Guinea) — September 1989
Scientific Event Alert Network Bulletin, vol. 14, no. 9 (September 1989)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) Occasional minor ash emission
Please cite this report as:
Global Volcanism Program, 1989. Report on Manam (Papua New Guinea). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 14:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198909-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"There was little or no change in the (low) level of activity in September. Southern Crater emissions were mostly weak white vapours occasionally containing grey or brown ash in small quantities. Weak deep rumblings were heard at the Observatory on 20, 21, and 23 September. Main Crater released small volumes of white vapour. Seismic activity remained at a low inter-eruptive level with ~900 small B-type events recorded daily. No significant tilt changes were recorded."
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.