Sorik Marapi Volcano, North Sumatra, Indonesia
5 June 2013

Note: The area of coverage in this Ikonos image is 1.05 km x 1.05 km.
The reduced resolution image on display has undergone compression and so does not represent the true resolution of the original satellite image.

The 2145 m high andesitic stratovolcano of Sorik Marapi is in north Sumatra, immediately north of the equator. Hot springs, mud pools, and fumaroles -- found near the crater and on the flanks of the volcano -- indicate its large hydrothermal system. The volcano is known for its huge crater lake and frequent phreatic eruptions. The hot lake that fills its steep-sided crater is nearly 500 m across and its water is extremely acidic, being high in sulphates and chlorides. The volcano was last active in 2011, spewing ash and giving rise to volcanic tremors. Past pyroclastic eruptions have strewn volcanic material ranging from ash to boulder on the steep bare inner walls of the crater. A past pyroclastic flow spilled over the eastern rim of the volcano. Elsewhere, the volcanic slopes are covered with dense vegetation, although evidences of past eruptions can be viewed through small gaps in the canopy.