Report on Lokon-Empung (Indonesia) — 5 October-11 October 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
5 October-11 October 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Lokon-Empung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 October-11 October 2011. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
CVGHM reported that on 10 October white and gray plumes rose 100-300 m above Tompaluan crater, in the saddle between the Lokon-Empung peaks. Based on information from CVGHM, the Darwin VAAC reported that on 11 October an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. The Alert Level remained at 3 (on a scale of 1-4).
Geological Summary. The Lokong-Empung volcanic complex, rising above the plain of Tondano in North Sulawesi, includes four peaks and an active crater. Lokon, the highest peak, has a flat craterless top. The morphologically younger Empung cone 2 km NE has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century. A ridge extending 3 km WNW from Lokon includes the Tatawiran and Tetempangan peaks. All eruptions since 1829 have originated from Tompaluan, a 150 x 250 m crater in the saddle between Lokon and Empung. These eruptions have primarily produced small-to-moderate ash plumes that sometimes damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred.