PVMBG reported that during 2-8 September lava continued to effuse from Karangetang’s Main Crater (S) and Dua Crater (N), traveling as far as 1.5 km down the Nanitu, Pangi, and Sense drainages on the SW flank. Sometimes dense white plumes rose to 200 m above the summit. According to the Darwin VAAC a diffuse ash plume rose almost 350 m above the summit and drifted SE on 7 September. The Alert Level remained at 2 (on a scale of 1-4).

Geological Summary. Karangetang (Api Siau) volcano lies at the northern end of the island of Siau, about 125 km NNE of the NE-most point of Sulawesi. The stratovolcano contains five summit craters along a N-S line. It is one of Indonesia's most active volcanoes, with more than 40 eruptions recorded since 1675 and many additional small eruptions that were not documented (Neumann van Padang, 1951). Twentieth-century eruptions have included frequent explosive activity sometimes accompanied by pyroclastic flows and lahars. Lava dome growth has occurred in the summit craters; collapse of lava flow fronts have produced pyroclastic flows.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)