Report on Sinabung (Indonesia) — 29 July-4 August 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 July-4 August 2015
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2015. Report on Sinabung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 29 July-4 August 2015. Smithsonian Institution and US Geological Survey.
3.17°N, 98.392°E; summit elev. 2460 m
All times are local (unless otherwise noted)
On 4 August BNPB reported that the eruption at Sinabung continued at a very high level. Lava was incandescent as far as 1.5 km SE and E down the flanks, and multiple avalanches were detected. Pyroclastic flows traveled at most 3 km ESE and SE, and ash plumes rose 2 km. The Alert Level remained at 4 (on a scale of 1-4), with an exclusion zone of 7 km from the volcano on the SE sector, and 6 km in the E sector. There were 3,152 families (11,114 people) displaced in 10 shelters, and an additional 2,053 families (6,179 people) in temporary shelters.
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.