Report on Lokon-Empung (Indonesia) — 14 September-20 September 2016
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 September-20 September 2016
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2016. Report on Lokon-Empung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 14 September-20 September 2016. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
Although inclement weather sometimes obscured views of Lokon-Empung's Tompaluan Crater, PVMBG reported that during 1-14 September observers at the post in Kakaskasen Tomohon (North Sulawesi, 4 km from the crater) saw white plumes rising as high as 250 m above the crater. The number of shallow volcanic earthquakes was the highest on 1 September (20 recorded), and then fluctuated between 1 and 4 per day during 2-14 September. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were reminded not to approach the crater within a radius of 1.5 km.
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.