PVMBG described activity at Sinabung during 8-15 March based on observations from a post in the Ndokum Siroga village, 8.5 km away. Dense white plumes rose from the lava dome daily, as high as 1 km on most days; plumes rose 2 km on 12 March. Incandescent material originating from various parts of the lava dome traveled up to 2 km S and SE. Tremor and volcanic earthquakes were detected, and signals representing avalanches from the unstable and still-growing dome increased. Sulfur dioxide emissions varied between 300 and 598 tons per day. Observations on 13 March showed that lava from the dome had flowed 2.4 km downslope. The report also noted that three people burned during a pyroclastic flow on 1 February later died in the hospital bringing the total number of casualties from that day to 17. The Alert Level remained at 4 (on a scale of 1-4). Visitors and tourists were prohibited from approaching the crater within a radius of 5 km.

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.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)