Report on Karangetang (Indonesia) — 22 January-28 January 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 January-28 January 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, 22 January-28 January 2003. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
Moderate volcanic activity continued at Karangetang during 13-26 January. Low-level ash plumes rose above North and South craters, incandescent glow rose to 50 m above the crater, and booming noises were sometimes heard at the observation post. On 14 January two ash explosions occurred at South crater, ejecting incandescent material that fell up to 50 m around the crater. Some of the material traveled as far as 200 m into the Beha River. An ash column rose to 300 m and ash fell into the E part of the sea. Karangetang remained at Alert Level 3 (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.