Report on Manam (Papua New Guinea) — May 1995
Bulletin of the Global Volcanism Network, vol. 20, no. 5 (May 1995)
Managing Editor: Edward Venzke.
Manam (Papua New Guinea) Increased vapor emissions, red glow, and rumbling noises
Please cite this report as:
Global Volcanism Program, 1995. Report on Manam (Papua New Guinea). In: Venzke, E (ed.), Bulletin of the Global Volcanism Network, 20:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199505-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"During the first half of May, S Crater was quiet and gently released white vapour in small to moderate volumes. Summit glow was observed on the 4th only. During the second half of the month, the rate of white vapour emissions was generally the same, but small to large volumes of blue vapour were gently released as well. The blue vapour emissions were seen on 15, 18-20, 23-24, 27, and 29 May. Steady weak red glow was observed on 17-19, 25, and 28-31 May. Weak rumbling noises were heard on 15, 17-18, 22, and 25 May. Main Crater emissions consisted of white vapour released gently in small to moderate volumes. No noise was heard and no crater glow was seen. Seismicity showed a marginal increase during the second half of the month, reflecting changes in the observed visual activity for the same period. The water-tube tiltmeters showed 1.5 µrad of radial deflation."
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: Ima Itikarai and Ben Talai, RVO.