Report on Lokon-Empung (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 Lokon-Empung (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 31 January-6 February 2001. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
The VSI reported that volcanic activity increased in comparison to the previous week. Explosions began occurring at 1920 on 28 January and produced glowing ejecta (volcanic bombs) that fell on the N slope of the volcano. The height of the ash cloud that was produced by the eruption could not be measured due to unfavorable weather conditions. A strong sulfurous smell was detected from Kakaskasen observatory. On the morning of 29 January an ash plume rose continuously up to 300 m above the crater. The Alert Level at the volcano was raised during the report period from level 2 to 3 (on a scale of 1-4).
Geologic Background. The twin volcanoes Lokon and Empung, rising about 800 m above the plain of Tondano, are among the most active volcanoes of Sulawesi. Lokon, the higher of the two peaks (whose summits are only 2 km apart), has a flat, craterless top. The morphologically younger Empung volcano to the NE has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century, but all subsequent eruptions have originated from Tompaluan, a 150 x 250 m wide double crater situated in the saddle between the two peaks. Historical eruptions have primarily produced small-to-moderate ash plumes that have occasionally damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred. A ridge extending WNW from Lokon includes Tatawiran and Tetempangan peak, 3 km away.