Report on Manam (Papua New Guinea) — 11 March-17 March 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 11 March-17 March 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, 11 March-17 March 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 1-18 March although inclement weather made crater observations difficult; no noises were reported. Seismicity had slowly and erratically increased since 28 February, peaked on 13 March and remained at that level through 15 March, and then increased again through 18 March. The seismicity was characterized by small-to-moderate, sub-continuous, and continuous volcanic tremor. Discrete low-frequency earthquakes were also recorded.
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)