Report on Karangetang (Indonesia) — 14 November-20 November 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 November-20 November 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, 14 November-20 November 2001. Smithsonian Institution and US Geological Survey.
2.781°N, 125.407°E; summit elev. 1797 m
All times are local (unless otherwise noted)
During 5-11 November volcanic activity decreased at Karangetang in comparison to the previous week. No lava flows had been observed since 25 October. White plumes rose 100 m over the main crater and 50 m above Crater II. A "red reflection" was visible up to 20 m over the volcano. Multiphase earthquakes associated with lava dome growth were recorded. During 12-18 November visual observations revealed an increase in gas pressure, and plume emissions rising 600 m above the main crater. In addition, volcanic earthquakes increased in comparison to the previous week and no multiphase earthquakes were recorded. 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.