Based on reports from PVMBG, BNPB reported on 8 and 9 February that seismicity at Sinabung continued to be dominated by hybrid earthquakes, indicating pressure below the crater and a growing lava dome. Earthquakes associated with avalanches increased. The 9 February report noted that the number of displaced people reached 32,351 (9,991 families) in 42 evacuation centers. Refugees from 17 villages outside the 5-km radius were allowed to return to their homes, starting with four villages during the first phase.

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: Badan Nacional Penanggulangan Bencana (BNPB)