Report on Lewotobi (Indonesia) — 28 March-3 April 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 28 March-3 April 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Lewotobi (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 28 March-3 April 2012. Smithsonian Institution and US Geological Survey.
8.542°S, 122.775°E; summit elev. 1703 m
All times are local (unless otherwise noted)
CVGHM reported that seismicity at Lewotobi Lakilaki, one of two stratovolcanoes comprising Lewotobi, fluctuated but declined overall during 18 September 2011-25 March 2012. No significant changes were observed at the volcano. The Alert Level was lowered to 1 (on a scale of 1-4) on 29 March.
Observers of Lewotobi Perempuan, the second stratovolcano comprising Lewotobi, noted that during January-March diffuse white plumes rose 15 m above the crater and no significant changes had occurred. After 31 August 2011 through 25 March 2012 seismicity fluctuated but declined overall. On 29 March the Alert Level was lowered to 1.
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.