Report on Lokon-Empung (Indonesia) — August 1994
Bulletin of the Global Volcanism Network, vol. 19, no. 8 (August 1994)
Managing Editor: Richard Wunderman.
Lokon-Empung (Indonesia) Description of fumaroles in the active crater
Please cite this report as:
Global Volcanism Program, 1994. Report on Lokon-Empung (Indonesia). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 19:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199408-266100.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
"During our visit to the summit zone on 8 July, intense fumaroles escaped from several parts of the Tompaluan crater floor. This fumarolic activity was mainly concentrated in the N where an intracaldera structure was covered by yellow sulfur deposits. Many other fumaroles with sulfur deposits were also located in the S, E, and W parts of the crater. Temperatures measured with an electronic thermometer at the E fumaroles showed a maximum value of 95-96°C. The fumarolic gases were mainly composed of H2O and H2S."
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: H. Gaudru, C. Pittet, M. Auber, C. Bopp, and O. Saudan, EVS, Switzerland.