Report on Manam (Papua New Guinea) — 26 June-2 July 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 26 June-2 July 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Manam (Papua New Guinea). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 26 June-2 July 2019. 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 RSAM values at Manam began increasing on 27 June and then spiked from 540 to over 1,400 within a short period of time (~30 min). According to news articles, residents reported hearing thundering noises around 0100 on 28 June. An eruption plume was visible in satellite images around 0620 drifting SW, around the time residents reported the start of the eruption. The Darwin VAAC issued a notice stating that by 0910 the ash plume had risen to 15.2 km (50,000 ft) a.s.l. and was drifting SW. Pyroclastic flows descended the W and NE flanks. About 3,775 people evacuated their homes. Additional ash plumes rose to 4.6 km (15,000 ft) a.s.l. and drifted W, and by 1700 the higher-altitude plume had detached from the volcano and continued to drift SW. A thermal anomaly persisted on 29 June, and the next day an ash plume rose to 2.4 km (8,000 ft) a.s.l. and drifted W.
Air Niugini stopped all aircraft overnighting in Madang due to the eruption. On 30 June they resumed operations at Hoskins airport, after rerouting all flights out of nearby airports during 29-30 June.
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 basaltic-andesitic stratovolcano to its lower flanks. These 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 observed eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent 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.