Report on Sinabung (Indonesia) — 11 September-17 September 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 11 September-17 September 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Sinabung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 11 September-17 September 2013. Smithsonian Institution and US Geological Survey.
3.17°N, 98.392°E; summit elev. 2460 m
All times are local (unless otherwise noted)
CVGHM reported that seismicity at Sinabung fluctuated in 2012-2013, including during July-September 2013. During 1-14 September dense white plumes rose 100-150 m above the crater, and at 0255 on 14 September incandescence from the crater was observed. According to news articles an eruption at 0245 on 15 September produced an ash plume and ashfall in Sukameriah (50 km NE), Kutarayat, Kutagugung (16 km SW), and Berastagi (14 km E). About 3,000 people evacuated from areas within a 3-km radius of the volcano, and several flights at Medan's airport (55 km NW) were canceled. CVGHM raised the Alert Level to 3 (on a scale of 1-4).
An eruption at 1203 on 17 September ejected tephra and a dense ash plume that rose higher than the plume from 15 September. According to the Darwin VAAC, a pilot observed an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted 55 km SE. On 18 September a low-level ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE.
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.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC), United Press International, Agence France-Presse (AFP), The Jakarta Post