Report on Sinabung (Indonesia) — 4 April-10 April 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 4 April-10 April 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Sinabung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 4 April-10 April 2018. Smithsonian Institution and US Geological Survey.
3.17°N, 98.392°E; summit elev. 2460 m
All times are local (unless otherwise noted)
PVMBG and BNPB reported that an eruption at Sinabung at 1607 on 6 April generated a dark gray ash plume that rose 5 km above the crater, and a pyroclastic flow that descended the SE and SW flanks 3.5 km. The Alert Level remained at 4 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions of 7 km on the SSE sector, 6 km in the ESE sector, and 4 km in the NNE sector. According to news articles, ashfall affected hundreds of hectares of agricultural land in the district of Karo, North Sumatra, and the Alas Leuser airport was closed on 7 April due to ash. The Alert Level remained at 4 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions of 7 km on the SSE sector, 6 km in the ESE sector, and 4 km in the NNE sector.
Geologic Background. 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.