Report on Manam (Papua New Guinea) — April 1985
Scientific Event Alert Network Bulletin, vol. 10, no. 4 (April 1985)
Managing Editor: Lindsay McClelland..
Manam (Papua New Guinea) Strong explosions and glow with increased seismicity
Please cite this report as:
Global Volcanism Program, 1985. Report on Manam (Papua New Guinea). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 10:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198504-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"A period of intensified activity took place about 12-24 April. Stronger explosions occurred at both summit craters, particularly from the 19th to the 22nd. Weak glows from Main crater were observed on the 19th and 22nd, and from Southern crater on the 21st. Seismicity during mid-April reached a peak 5-10 times normal. No tilting was recorded in April following the 3 µrad of inflation in March."
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.