Report on Lokon-Empung (Indonesia) — 14 November-20 November 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
14 November-20 November 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Lokon-Empung (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 14 November-20 November 2001. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
Following a tectonic earthquake near Lokon on 19 October, activity increased at the volcano; high-frequency tremor occurred and gray emissions rose 50-250 m above Tompaluan crater. While fewer earthquakes were recorded during 12-18 November (10 per day) in comparison to the previous week (19 per day), the number of earthquakes was still above normal levels. No major changes in volcanic activity were seen at Lokon's summit. The Alert Level at Lokon remained at 2 (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.