Aral Sea

Aral Sea
  • Credit:

    Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC

This pair of true- and false-color Terra MODIS images features the Aral Sea in western Asia, between Kazakhstan to the north and Uzbekistan to the south. The Sea is actually a salt lake, and though it used to be the world’s fourth largest lake, it has been slowly shrinking since the 1970s when its two main rivers, the Syr Darya (north) and the Amu Darya (south), were diverted for agricultural purposes.

In these images, the waters of the eastern half of the lake are clouded by what is probably sediment. In the true-color image, the sediment appears as a bright milky green, while in the false-color image, the clouds are a dark blue against the black of clearer water. To the northeast and south of the Sea, vegetation is green against the tan surrounding deserts. In the true-color image, this vegetation is a deep green (almost black) color, while in the false color the vegetation it is an easier-to-see fluorescent green.

One feature that is harder to pick up in the true-color image is the prevalence of dry salt beds left by the slowly evaporating water. In true-color, they reflect bright white, while in the false-color image, these salt beds appear as a bright turquoise blue, and indicate how big the Sea used to be. Other dry salt beds are also scattered around the region.

Images & Animations

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  • JPEG 112 KB
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Metadata

  • Data Date:

    June 22, 2003
  • Visualization Date:

    July 8, 2003
  • Sensor(s):

    Terra - MODIS
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