Report on Karangetang (Indonesia) — 2 August-8 August 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 2 August-8 August 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Karangetang (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 2 August-8 August 2006. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
On 2 August, the Alert Level at Karangetang was raised to 4, the highest level. During 1-5 August, white plumes reached heights of 50-300 m (164-984 ft) above the summit (6,000-6,800 ft a.s.l.). Lava flows advanced hundreds of meters to over a kilometer E toward the Batu Awang river and S towards the Keting river during the reporting period. Incandescent rockfalls originating from the summit and ends of the lava flows traveled hundreds of meters E toward the Kahetang and Batu Awang rivers and S towards the Keting and Batang rivers. On 5 August, the Alert level was lowered to 3.
Geologic Background. 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 island. 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 in the historical record (Catalog of Active Volcanoes of the World: 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.