Recent activity at Manam has consisted of white vapor emissions from both the Main and Southern craters, and low seismicity (BGVN 28:03). The Rabaul Volcanological Observatory reported that the two vents in the Main crater gently released weak, thin white vapor during 7-12 May, with occasional white-gray emissions on 11 May. Fine ashfall resulting from occasional emissions of thin white gray ash plumes from Main crater was reported on the NW side of the island on 17-19 and 23 May. No audible noise or glow was reported. Southern crater continued to gently release small amounts of thin white vapor. The volcano was quiet over the period 25-30 June, with both craters gently releasing occasional thin white vapor emissions and low seismicity.

Geological Summary. 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.

Information Contacts: Ima Itikarai, Rabaul Volcanological Observatory, P.O. Box 386, Rabaul, Papua New Guinea.