Report on Sinabung (Indonesia) — 1 January-7 January 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 1 January-7 January 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Sinabung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 1 January-7 January 2014. Smithsonian Institution and US Geological Survey.
3.17°N, 98.392°E; summit elev. 2460 m
All times are local (unless otherwise noted)
Badan Nacional Penanggulangan Bencana (BNPB) reported that during 30-31 December 2013 Sinabung continued to be very active. Ash plumes rose as high as 7 km above the lava dome, pyroclastic flows traveled as far as 3.5 km SE, and incandescent avalanches traveled 1.5 km SE. On 3 January the lava dome continued to grow and collapse. Pyroclastic flows occurred 172 times and traveled 2-4 km SE, and ash plumes rose 2-6 km. Two villages located 6.5 km SE, Jerawa and Desa Pintu Besi, were evacuated. On 4 January pyroclastic flows were larger and more frequent. They continued to travel up to 5 km SE as well as 3.5 km SSE. Ash plumes rose 2-4 km. On 5 January the number of hybrid earthquakes increased, indicating a growing lava dome, and pyroclastic flows traveled 1.5-4.5 km SE. During 4-5 January pyroclastic flows were recorded 426 times. On 7 January ash plumes rose 1-6 km and drifted SW, and pyroclastic flows continued to travel 1.5-4.5 km SE. The number of refugees reached 22,145.
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.