Volcanoes Between Lakes Maninjau and Singkarak, Indonesia – November 1st, 20090.3S 100.1E
Three volcanoes, Mounts Tandikat, Singgalang and Marapi, are visible from left to right in this orthorectified image between Lake Maninjau (left) and Lake Singkarak (right) in West Sumatra, Indonesia.
Lake Maninjau rests inside a caldera that was formed by a volcanic eruption estimated to have occurred around 52,000 years ago. The caldera has a length of 20 km and a width of 8 km, while the lake itself is approximately 16 km long and 7 km wide with an area of 99.5 km². The average depth is 105 m, with a maximum depth of 165 m.
The natural outlet for excess water is the Antokan River, located on the west side of the lake. It is the only lake in Sumatra which has a natural outlet to the west coast. Since 1983 this water has been used to generate hydroelectric power for West Sumatra.
Lake Singkarak, on that other hand, has a slightly larger area of 107.8 km², being approximately 21 km long and 7 km wide. The natural outlet for excess water is the Ombilin River which flows eastward to the Strait of Malacca. A hydroelectric project however has diverted most of the lake outflow to the Anai River which flows westward into the Indian Ocean near the city of Padang (visible along the coast in the bottom right corner of the full image).