PVMBG reported that each day during 27 October-2 November avalanches descended Sinabung’s E and SE flanks as far as 1 km. Pyroclastic flows traveled 1-2.5 km down the same flanks almost daily. According to a news article, an eruption at 0752 on 29 October produced an ash plume that rose 1.5 km and caused ashfall in areas within 10 km downwind, particularly in Kabanjahe (13 km SE) and Berastagi (13 km E). An eruptive event at 2358 on 2 November generated an ash plume that rose 1.5 km and drifted E. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

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.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), The Jakarta Post