Report on Lewotobi (Indonesia) — 21 September-27 September 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 21 September-27 September 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Lewotobi (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 21 September-27 September 2011. Smithsonian Institution and US Geological Survey.
8.542°S, 122.775°E; summit elev. 1703 m
All times are local (unless otherwise noted)
CVGHM raised the Alert Level for Lewotobi Lakilaki, one of two stratovolcanoes composing Lewotobi, to 2 (on a scale of 1-4) on 22 September due to increased seismicity since 17 September and visual observations. Although no significant changes in the volcano were observed, diffuse white plumes rose 15 m above the crater. Visitors and residents were prohibited from going within a 1-km radius of Lewotobi Lakilaki.
Geologic Background. The Lewotobi "husband and wife" twin volcano (also known as Lewetobi) in eastern Flores Island is composed of the Lewotobi Lakilaki and Lewotobi Perempuan stratovolcanoes. Their summits are less than 2 km apart along a NW-SE line. The conical Lakilaki has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has erupted only twice in historical time. Small lava domes have grown during the 20th century in both of the crescentic summit craters, which are open to the north. A prominent flank cone, Iliwokar, occurs on the E flank of Perampuan.