Report on Manam (Papua New Guinea) — 6 May-12 May 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 May-12 May 2015
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2015. Report on Manam (Papua New Guinea). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 6 May-12 May 2015. Smithsonian Institution and US Geological Survey.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
RVO reported that activity at both Manam's Southern Crater and Main Crater was low during 1-30 April; variable amounts of white emissions rose from both craters. Incandescence from Southern Crater was visible at night during 2, 6, 8-10, 15, 21, and 29-30 April, and from main Crater during 8-10, 15, 21, and 29-30 April. The seismicity was characterized by sub-continuous and continuous volcanic tremor, and discrete low-frequency earthquakes. Sulfur dioxide flux was slightly higher at the end of April; distinct sulfur dioxide levels were detected on 2 May.
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.
Source: Rabaul Volcano Observatory (RVO)