Mount Sinabung (Indonesian: Gunung Sinabung) is a Pleistocene-to-Holocene stratovolcano of andesite and dacite in the Karo plateau of Karo Regency, North Sumatra, Indonesia. Many lava flows are on its flanks.
Solfataric activities (cracks where steam, gas, and lava are emitted) were seen at the summit in 1912, but no historical eruptions had been recorded until the eruption in the early hours of 29 August 2010.
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 volcano is at the southern end of the four overlapping summit craters.
Sinabung volcano contains four overlapping summit craters, with solfatara activity present during the 20th century. The cone shows evidence of many lava flows.
Crater 1. Diameter 300 m.
Crater 2. Diameter 150 m. Contains crater lake.
Crater 3 (Batu Sigala). 160 m x 130 m. Contains crater lake.
Crater 4. Diameter 60 m.
Strong solfatara activity is found at crater 2 and 3.
Solfataric activities (cracks where steam, gas, and lava are emitted) were last observed at the summit in 1912; recent documented events include an eruption in the early hours of 29 August 2010 and eruptions in September and November 2013, January, February and October 2014. Sinabung still has daily eruptions with pyroclastic flows (February 2015)