Report on Manam (Papua New Guinea) — April 1995
Bulletin of the Global Volcanism Network, vol. 20, no. 4 (April 1995)
Managing Editor: Richard Wunderman..
Manam (Papua New Guinea) Both seismicity and tilt low; gently steaming
Please cite this report as:
Global Volcanism Program, 1995. Report on Manam (Papua New Guinea). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 20:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199504-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
Although activity at Manam remained low in April, throughout the month both Main and Southern Craters infrequently discharged white vapor. Southern Crater discharged wispy blue vapor on the 11th; faint rumbling sounds were heard on one occasion only (at 2330 on 23 April); weak night glow was seen mainly during the 2nd and 4th weeks of April, when then summit was clearly visible. Main Crater issued occasional, thin to thick white vapors. These emissions were gentle and were not accompanied by night glow or audible sounds. The seismicity fluctuated at a low level throughout the month. No significant change was shown by the water-tube tiltmeter located about 4 km SW from the summit.
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: David Lolok and Ben Talai, RVO.