The Volcanological Survey of Indonesia (VSI) raised the volcanic alert level of Sinabung volcano to 3 (out of 4) after new eruption occurred over night, September 14/15, 2013. According to press articles, more than 3 700 people from nearby villages have been evacuated.
Map of disaster prone areas. Image credit.: VSI
Since its first historical eruption in September 2010, the volcanic activity of the mountain tends to decrease with fluctuations.
This time-lapse video from the VSI webcam shows a degassing plume in the evening, a possible incandescent spot at the volcano's summit, and bright glow in an area left below the summit starting at 02:55 local time. Judging from the images, it seems to be caused glowing rockfalls from rapidly extruded lava in that area, or impacts from explosive activity (less likely). No significant ash plume could be spotted on satellite data (VD).
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, 2460-m-high andesitic-to-dacitic volcano is at the southern end of the four overlapping summit craters. An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks of Sinabung 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 (GVP).
Featured image: VSI