Logo link to homepage

Report on Karangetang (Indonesia) — 22 September-28 September 2010


Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 22 September-28 September 2010
Managing Editor: Sally Sennert.

Please cite this report as:

Global Volcanism Program, 2010. Report on Karangetang (Indonesia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 22 September-28 September 2010. Smithsonian Institution and US Geological Survey.

Weekly Report (22 September-28 September 2010)



2.781°N, 125.407°E; summit elev. 1797 m

All times are local (unless otherwise noted)

CVGHM reported that during 1-7 September lava seen from the observation post (5 km SSW) traveled 75 m down Karangetang's flanks. Avalanches traveled as far as 1.5 km down the Batang (S), Batu Awang (E), and Nanitu drainages. Incandescent material was ejected 350 m above the crater. During 8-21 September lava traveled 500 m down the flanks. Avalanches originating from the end of the lava flow traveled as far as 2 km down the Batang, Kahetang (E), and Nanitu drainages. During 18-20 September material was ejected 300-500 m above the crater. Ashfall was reported in areas to the NW. On 21 and 22 September incandescent material traveled down multiple drainages. Strombolian activity was observed on 22 September; material ejected 50 m high fell back down around the crater. That same day the Alert level was raised to 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.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)