Report on Manam (Papua New Guinea) — May 1996
Bulletin of the Global Volcanism Network, vol. 21, no. 5 (May 1996)
Managing Editor: Richard Wunderman.
Manam (Papua New Guinea) Low level activity persists
Please cite this report as:
Global Volcanism Program, 1996. Report on Manam (Papua New Guinea). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 21:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199605-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
Low-level activity persisted during May as in previous months (BGVN 21:04). Both summit craters emitted white vapor in variable quantity. Blue vapor from South Crater was seen on 28 and 29 May, and weak roaring noises were heard on the evening of 6 May. Between 1 and 5 May the daily occurrence of low-frequency earthquakes ranged from 440 to 690 events/day. This value increased up to 800-1,690 events/day during 6-30 May. On the 31st the seismicity dropped to the early May level.
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.