Report on Manam (Papua New Guinea) — 26 April-2 May 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 26 April-2 May 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Manam (Papua New Guinea). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 26 April-2 May 2017. 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 periods of Strombolian activity at Manam’s Southern Crater were observed during 24-30 April, and roaring and rumbling was heard. Explosions were also heard and sometimes followed by detectable shock waves. Most incandescent tephra fell back into the crater but some were deposited in the SW and SE valleys. Strombolian activity declined for a period on 25 April, and only dense gray ash plumes were seen rising from the crater. Activity was lower during 26-27 April. Strombolian explosions returned on 28 April; some of the explosions were strong and rattled nearby houses. One strong explosion and banging was heard at the Bogia Government Station. A period of moderate to moderately-high Strombolian activity was detected during 0200-0330 on 30 April. A small pyroclastic flow traveled down the SW valley, stopping around 200 m a.s.l. Scoria (up to 40 mm in diameter) and ash fell on the E side of the island in Abaria and Boakure.
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)