The Alert Status of Karangetang was raised on 13 July from 2 to 3 (on a scale of 1-4) due to increased eruptive activity. On 12 July, lava flows were observed moving E toward the Kahetang and Batu Awang rivers at a maximum distance of 2 km from the vent. White emissions reached a height of 600 m above the crater (7,800 ft a.s.l.).

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)