Report on Karangetang (Indonesia) — 11 July-17 July 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 11 July-17 July 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Karangetang (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 11 July-17 July 2001. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
After eruptions occurred on 25 and 29 June, volcanic activity continued at high levels at Karangetang. During 30 June to 8 July seismographs recorded signals that represented small explosions, avalanches, and an average of 33 multiphase earthquakes per day. During this period a gray plume was emitted from the volcano, and lava avalanches traveled as far as 2.5 km down the Keting River and 750 m down the Kahetang River. The volcano is 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.