Report on Raung (Indonesia) — 12 August-18 August 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 August-18 August 2015
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2015. Report on Raung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 12 August-18 August 2015. Smithsonian Institution and US Geological Survey.
8.119°S, 114.056°E; summit elev. 3260 m
All times are local (unless otherwise noted)
PVMBG reported that the eruption at Raung was ongoing during 24 July-10 August. Ash plumes rose 1.5 km above the crater and crater incandescence was visible. Seismicity fluctuated but remained elevated; RSAM values peaked on 4 August (the highest recorded since the beginning of the eruption) and then decreased again. The Alert Level remained at 3 (on a scale of 1-4), and the public was reminded not to approach the crater within a 3-km radius. Based on satellite observations and wind data, the Darwin VAAC reported that during 12-14, 16, and 18 August multiple ash plumes from Raung rose to altitudes of 3.7-4 km (12,000-13,000 ft) a.s.l. and drifted 20-110 km W and WSW.
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.