Report on Karangetang (Indonesia) — 29 May-4 June 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 May-4 June 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Karangetang (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 29 May-4 June 2002. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
During 22 April-26 May, small steam plumes rose 50-500 m above Karangetang's main crater and 10- to 25-m-high "red reflections" were visible above the crater at night. An ash explosion on 12 May at 1116 rose 750 m above the crater and drifted E over the sea. The eruption was followed by lava avalanches that traveled S down the Batu Awang river, and E down the Kahetang river to a maximum run-out distance of ~500 m. Another explosion occurred on 26 May at 1747; it produced an ash cloud to a height of 300 m above the crater that drifted to the W. Karangetang remained at Alert Level 2 (on a scale of 1-4).
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.