Report on Lokon-Empung (Indonesia) — April 1987
Scientific Event Alert Network Bulletin, vol. 12, no. 4 (April 1987)
Managing Editor: Lindsay McClelland.
Lokon-Empung (Indonesia) Diminished activity; continuous white plume
Please cite this report as:
Global Volcanism Program, 1987. Report on Lokon-Empung (Indonesia). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 12:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198704-266100.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
Activity diminished during April. A white plume was continuously emitted from Tompaluan Crater to heights of 200-400 m. During the first half of the month, an average of 15 tectonic earthquakes were detected daily. No seismic activity was reported for the second half 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: VSI; T. Casadevall, USGS & VSI.