Report on Sinabung (Indonesia) — 14 July-20 July 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
14 July-20 July 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Sinabung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 14 July-20 July 2021. Smithsonian Institution and US Geological Survey.
3.17°N, 98.392°E; summit elev. 2460 m
All times are local (unless otherwise noted)
Video taken on 13 July and posted on social media showed new vents on the upper W flank of Sinabung that were producing steam-and-ash emissions. PVMBG reported that white-and-gray plumes rose 100-300 m from the summit and drifted E and SE. During 14-18 June white plumes rose as high as 300 m. An eruptive event that began around 1850 on 19 July and lasted about 11 minutes produced an ash plume that rose 1 km and drifted ESE. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.
Geological Summary. Gunung Sinabung is a Pleistocene-to-Holocene stratovolcano with many lava flows on its flanks. The migration of summit vents along a N-S line gives the summit crater complex an elongated form. The youngest crater of this conical andesitic-to-dacitic edifice is at the southern end of the four overlapping summit craters. The youngest deposit is a SE-flank pyroclastic flow 14C dated by Hendrasto et al. (2012) at 740-880 CE. An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks in 1912. No confirmed historical eruptions were recorded prior to explosive eruptions during August-September 2010 that produced ash plumes to 5 km above the summit.