Report on Lokon-Empung (Indonesia) — 30 January-5 February 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 30 January-5 February 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Lokon-Empung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 30 January-5 February 2013. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
According to news articles, Lokon-Empung erupted twice on 31 January, producing an ash plume that rose 800 m after the first eruption. Seismicity had increased the day before. In another article the head of the Lokon observation post reported that eruptions from Lokon occurred daily, and specifically that nine eruptions had occurred on 2 February.
Based on a ground report from CVGHM, the Darwin VAAC reported that an ash plume from Lokon-Empung rose to an altitude of 4 km (13,000 ft) a.s.l. on 3 February. Ash was not detected in satellite imagery.
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.