After several weeks of weak-to-moderate vapor emission, South Crater produced a small eruption on 26 October, sending thick white-gray ash clouds ~500-600 m above the summit. Roaring and rumbling noises accompanied the ash emissions. Weak projection of incandescent lava fragments was visible at the crater area. The activity persisted until 28 October but at a slightly reduced level. During 29-31 October activity diminished, releasing only white vapor at weak-to-moderate rates. Summit crater glow was visible throughout October.

Main Crater remained quiet during October, releasing gentle emissions of white vapor. No noises were heard and no night glow was visible at the crater. Seismic activity was moderate throughout October, with ~1,100-1,400 low-frequency earthquakes/day.

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: B. Talai and H. Patia, RVO.