Report on Lokon-Empung (Indonesia) — 29 May-4 June 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 May-4 June 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Lokon-Empung (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 29 May-4 June 2002. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
Seismicity at Lokon-Empung during 22 April-26 May remained above background levels. Several deep and shallow volcanic, tectonic, and small explosion earthquakes occurred. Thin, white plumes rose 50-250 m above the crater rim. Lokon-Empung remained at Alert Level 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.