Report on Raung (Indonesia) — 20 January-26 January 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 January-26 January 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, 20 January-26 January 2021. Smithsonian Institution and US Geological Survey.
8.119°S, 114.056°E; summit elev. 3260 m
All times are local (unless otherwise noted)
A brown-gray ash plume from Raung rose 100-400 m above the crater rim and drifted E at 0520 on 21 January, prompting PVMBG to raise the Alert Level to 2 (on a scale of 1-4). Gray plumes rose 200-600 m above the crater rim and drifted E on the next day. White-and-gray plumes rose 200-500 m on 23 January and drifted WSW, and crater incandescence was visible in webcam images. During 24-25 January ash plumes rose 500 m and drifted E and S, and Strombolian activity was visible.
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.