Report on Manam (Papua New Guinea) — February 1993
Bulletin of the Global Volcanism Network, vol. 18, no. 2 (February 1993)
Managing Editor: Edward Venzke.
Manam (Papua New Guinea) Weak emissions; discontinuous low-amplitude tremor
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, 18:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199302-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Low-level activity continued at Manam's S crater. Emissions consisted of weak white vapour, with occasional light ash content. A weak, fluctuating glow was seen above the crater whenever atmospheric conditions allowed. The main crater released only whisps of white vapour. Seismicity throughout the month consisted of discontinuous low-amplitude tremor and low-frequency events of small amplitude. Tiltmeter measurements showed no trends."
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: R. Stewart, P. de Saint-Ours, and C. McKee, RVO.