"Both Southern and Main Craters released white [emissions] with occasional grey [ash] and blue vapours at a low-moderate rate. No subterranean noises or summit glow were observed. Seismicity was low-moderate with 800-1,150 B-type volcanic events daily and sub-continuous low-amplitude tremor recorded throughout the month. An inflationary tilt change of 1.5 µrad was recorded in August after a 1.3 µrad deflationary change recorded in July."

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: P. Lowenstein and B. Talai, RVO.