High-impact eruption at Manam volcano, 2 000 people flee from lava flows, ash up to 15 km a.s.l., PNG

A powerful eruption took place at PNG's Manam volcano at 20:00 UTC, August 24, 2018 (06:00 local time, August 25). This sudden, high-impact eruption sent volcanic ash up to 15 km (50 000 feet) above sea level and produced lava flows that forced 2 000 villagers to flee. Islanders reported that ash and other debris from the eruption was so thick that sunlight was totally blocked for a few hours.

The director of the PNG National Disaster Center said three villages were directly impacted by the lava flow and residents had to be evacuated.

The Rabaul Volcano Observatory (RVO) said it was an unusually large eruption. Ash falls were so heavy that trees broke under the weight, it said.

"The most affected areas are Baliau and Kuluguma and due to the very poor visibility caused by the ash fall, people are using torchlight to move around," RVO said.

"There are no casualties as far as we know but we are telling people to keep away from valleys for risk of mudflows. There’s a heavy thick blanket of ash on the flank and if there is heavy rainfall, we are making people aware of the threat," RVO’s Steve Saunders told Reuters.

The initial phase of the eruption is now over but a new vent had opened, indicating more activity could be expected.

A major eruption of this volcano forced the evacuation of some 9 000 people in 2004. Many of them still reside at a camp on the outskirts of Madang.

Geological summary

The 10-km-wide (6.2 miles) island of Manam, lying 13 km (8 miles) 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 1 807-m-high (5 928 feet) 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. (GVP)

Featured image credit: Scott Waide