Report on Raung (Indonesia) — 3 April-9 April 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 3 April-9 April 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Raung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 3 April-9 April 2013. Smithsonian Institution and US Geological Survey.
8.119°S, 114.056°E; summit elev. 3260 m
All times are local (unless otherwise noted)
CVGHM reported that during March white plumes rose at most 400 m above Raung. Seismicity decreased significantly on 25 March, and tremor was absent starting in April. On 5 April the Alert level was lowered to 2 (on a scale of 1-4). Visitors and residents were warned not to approach the crater within a 1.8-km radius.
Geologic Background. Raung, one of Java's most active volcanoes, is a massive stratovolcano in easternmost Java that was constructed SW of the rim of Ijen caldera. The unvegetated summit is truncated by a dramatic steep-walled, 2-km-wide caldera that has been the site of frequent historical eruptions. A prehistoric collapse of Gunung Gadung on the W flank produced a large debris avalanche that traveled 79 km, reaching nearly to the Indian Ocean. Raung contains several centers constructed along a NE-SW line, with Gunung Suket and Gunung Gadung stratovolcanoes being located to the NE and W, respectively.