Report on Ranakah (Indonesia) — 19 October-25 October 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 19 October-25 October 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Ranakah (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 19 October-25 October 2011. Smithsonian Institution and US Geological Survey.
8.62°S, 120.52°E; summit elev. 2350 m
All times are local (unless otherwise noted)
CVGHM reported that throughout September and during 1-12 October diffuse white plumes rose 10-15 m above the Anak Ranakah lava dome. Plumes were not observed during 13-21 October. Starting on 1 July, seismicity had increased to a peak level on 15 August then declined through 20 October. Based on visual observations, seismicity, and deformation data, CVGHM lowered the Alert Level to 2 (on a scale of 1-4) on 22 October.
Geologic Background. A new lava dome, named Anak Ranakah (Child of Ranakah) was formed in 1987 in an area without previous historical eruptions at the base of the large older lava dome of Gunung Ranakah. An arcuate group of lava domes extending westward from Gunung Ranakah occurs on the outer flanks of the poorly known Poco Leok caldera on western Flores Island. Pocok Mandosawa lava dome, at 2350 m the highest point on the island of Flores, lies west of Anak Ranakah.