Report on Manam (Papua New Guinea) — April 1999
Bulletin of the Global Volcanism Network, vol. 24, no. 4 (April 1999)
Managing Editor: Richard Wunderman.
Manam (Papua New Guinea) Mild eruptive activity at Main Crater; Southern Crater is quiet
Please cite this report as:
Global Volcanism Program, 1999. Report on Manam (Papua New Guinea). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 24:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199904-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
Mild, irregular, eruptive activity continued from Manam's Main Crater, while Southern Crater remained quiet. Main Crater continued to emit minor pale gray ash intermittently throughout March and April, with emissions rising to ~500 m above the summit before being blown to the NW with resulting fine ashfall. There were no reports of any noise or nighttime glow. Southern Crater was quiet, releasing white vapor only. However, a weak steady red glow was visible during 17-21 April. Seismic activity was low and there were no significant change in ground deformation.
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: Herman Patia, Rabaul Volcano Observatory (RVO), P.O. Box 386, Rabaul, Papua New Guinea.