Report on Sinabung (Indonesia) — 13 November-19 November 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 13 November-19 November 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, 13 November-19 November 2013. Smithsonian Institution and US Geological Survey.
3.17°N, 98.392°E; summit elev. 2460 m
All times are local (unless otherwise noted)
Based on webcam data and satellite images, the Darwin VAAC reported that during 13-14 November an ash plume from Sinabung rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted almost 150 km NW and W. According to a news article, a pyroclastic flow traveled 1.2 km down the SE flank on 14 November, prompting more evacuations from villages near the base of the volcano. The article noted that more than 7,000 people had been evacuated from 10 villages.
An explosion observed with the webcam on 18 November produced an ash plume that rose to an altitude of 7.6 km (25,000 ft) a.s.l. About 30 minutes later an ash plume also visible in satellite images rose to an altitude of 11.3 km (37,000 ft) a.s.l. and drifted 65 km W. Four hours later satellite images showed ash plumes at an altitude of 9.1 km (30,000 ft) a.s.l. to the W of Sinabung and at an altitude of 4.6 km (15,000 ft) a.s.l. over the crater. On 19 November the webcam recorded an ash plume that rose to an altitude of 4.6 km (15,000 ft) a.s.l. over the crater. A news article stated that later that night that an ash plume rose to an altitude of 10 km (32,800 ft) a.s.l.
A news article from 20 November noted that volcanologists updated the hazard map for Sinabung. The second-tier disaster-prone area, previously defined as a radius of 2-3 km from Sinabung’s crater, was expanded to 4-5 km.
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.