Report on Raung (Indonesia) — 4 August-10 August 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
4 August-10 August 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Raung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 4 August-10 August 2021. 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 neither explosive nor effusive activity had been recorded at Raung since February, and emissions were not observed during 1 July-8 August. Seismicity had declined and deformation data indicated a trend of deflation. The Alert Level was lowered to 1 (on a scale of 1-4) on 9 August, and the public was warned to stay away from the crater.
Geological Summary. 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.