Report on Lokon-Empung (Indonesia) — 17 September-23 September 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 September-23 September 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Lokon-Empung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 17 September-23 September 2014. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
PVMBG reported that during 8-14 September observers of Lokon-Empung noted white plumes rising 25-100 m above Tompaluan Crater. On 13 September three explosions from Tompaluan Crater, at 0300, 1146, and 1229, produced white plumes that rose at most 500 m above the crater. Seismicity decreased sharply after the13 September events but continued to remain high relative to the levels detected prior to 10 September. The Alert Level remained at 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.