RVO reported that on 23 April dense white vapor plumes occasionally rose from Manam's Southern Crater. During 25-28 April ash clouds rose from the new sub-terminal vent E of Southern Crater inside southeast valley. The ash clouds rose 600 m and drifted NW. Loud booming noises were heard each day; however, between 0700 and 1900 on 27 April the noises became frequent, louder, and explosive in nature, and were heard at Bogia, 25-30 km SSW of Manam on the N coast of the mainland. Strong explosions vibrated structures on the island.

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)