RVO reported that activity at both Manam's Southern Crater and Main Crater was low during 1-15 December; white vapor emissions rose from both craters. Light gray ash clouds rose from Southern Crater during 6, 10, and 13-14 December, and incandescence from the crater was observed during 6-10 and 12-13 December. Incandescence from Main Crater was visible during 11-13 and 15 December, and gray ash plumes rose from the crater during 13-14 December. No plumes from either crater rose more than 100 m during the reporting period.

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.

Source: Rabaul Volcano Observatory (RVO)