Report on Karangetang (Indonesia) — 31 January-6 February 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 31 January-6 February 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, 31 January-6 February 2001. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
The VSI reported that during 23-29 January explosive activity continued, with explosions on both 25 and 28 January. At 2227 on 25 January a minor explosion produced a thick ash plume that rose 700 m above the volcano, blew to the W, and dropped ash over the sea. The explosion also produced a lava avalanche that traveled ~1,250 m down the Kelitu River. The second explosion during the report period occurred at 2109 on 28 January and produced a Strombolian-type eruption with glowing ejecta that reached up to 300 m above the crater. In addition, a black ash-filled plume rose to ~1 km above the volcano. The explosion opened a new crater in the lava dome and produced a lava avalanche that traveled ~1.5 km down the W slope of the volcano. The volcano 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.