Report on Lokon-Empung (Indonesia) — May 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 5 (May 1991)
Managing Editor: Lindsay McClelland.
Lokon-Empung (Indonesia) Increased gas emission, then ash eruption
Please cite this report as:
Global Volcanism Program, 1991. Report on Lokon-Empung (Indonesia). In: McClelland, L. (ed.), Bulletin of the Global Volcanism Network, 16:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199105-266100.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
Gas emissions to 450 m height were observed during the morning and afternoon of 10 May. One week later (17-18 May), ash was erupted to 200-400 m height. Seismicity then decreased, with one deep and three shallow volcanic earthquakes recorded during the last week of May, down from six deep and nine shallow events the second week of the month.
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.
Information Contacts: W. Modjo, VSI.