Report on Karangetang (Indonesia) — 19 March-25 March 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
19 March-25 March 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Karangetang (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 19 March-25 March 2003. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
During 10-16 March, Karangetang's South crater generated low-level "white-gray ash emissions" and incandescence visible to 50 m above the crater. Incandescent lava avalanches traveled toward Kahetang, Batuawang, Batang, and Beha rivers. During the report period, there was a decrease in the number of earthquakes, and seismicity was dominated by 125 avalanche earthquakes. The Alert Level at Karangetang remained at 3 (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.