Report on Manam (Papua New Guinea) — June 1993
Bulletin of the Global Volcanism Network, vol. 18, no. 6 (June 1993)
Managing Editor: Edward Venzke.
Manam (Papua New Guinea) Ash emissions increase; moderate eruption in mid-July
Please cite this report as:
Global Volcanism Program, 1993. Report on Manam (Papua New Guinea). In: Venzke, E. (ed.), Bulletin of the Global Volcanism Network, 18:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199306-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
". . . Manam became more active in June. Southern Crater released occasionally forceful emissions of white-dark grey, ash-laden clouds rising 1-2 km above the summit crater until 15 June, when activity declined slightly. Occasional roaring and rumbling noises accompanied the emissions. Fluctuating crater glow and projections of incandescent fragments, ascending to as much as 125 m above the crater rim, were observed until 18 June. Main crater continued weak emissions of white vapour; no noise or glow was reported. The seismograph remained unoperational in June. Tilt measurements showed no significant changes."
A pilot report described an intermittent, very dense, dark gray plume . . . on 14 July that rose above 10 km altitude before being blown W; a lava flow was also noted. Australian radio reported on 16 July that an alert had been issued to residents on the N coast of Manam Island after an eruption of the volcano. Ash was reported to have fallen on the W and S parts of the island, with lava flows observed in the southern valleys.
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: D. Lolok and C. McKee, RVO; ICAO; Melbourne Radio Australia.