Based on webcam views, wind data models, and satellite images, the Darwin VAAC reported that during 23-27 October ash plumes rose from Sinabung. During 23-24 October ash plumes drifted 15-40 km N and SW. A small eruption observed on the webcam on 25 October produced a minor amount of ash that drifted SW; a later ash plume drifted almost 30 km WNW. The next day another eruption generated an ash plume that drifted E. Ash emissions on 27 October were recorded by the webcam. The VAAC noted that PVMBG reported an ash plume that rose to an altitude of 5.5 km (18,000 ft) a.s.l. and then dissipated.

On 27 October BNPB reported that activity at Sinabung remained high; on 26 October pyroclastic flows traveled 3.5 km S and avalanches occurred multiple times. Hot ash clouds rose 2 km. The report stated that 3,284 people from 1,018 families remained in evacuation shelters.

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: Darwin Volcanic Ash Advisory Centre (VAAC), Badan Nacional Penanggulangan Bencana (BNPB)