- According to our media spotlight “Disappearing Lake,” the Aral Sea has always been a saline (salty) lake, but it has become much saltier as its waters have receded. Why? Are there other examples of this phenomenon?
- Water evaporates, salt doesn’t. As water evaporates into the atmosphere, heavy minerals such as salts are left on the ground (creating salt flats) or in the remaining water. In the Aral Sea, this process has been augmented by human activity—incoming water has been prevented from actually reaching the sea, leaving literally tons of salt. As a result, the remaining water is saltier.
- This phenomenon is very common. It happens as saline lakes form in endorheic basins. Endorheic basins, such as the Aral Sea, don’t drain to a stream, lake, or ocean. The water that flows into these types of basins evaporates or seeps into the ground. Read more about endorheic basins here.
- The largest salt flats in the world, in the highlands of Bolivia, developed as the Andes Mountains formed and saltwater lakes evaporated, cut off from both their sources and drainage outlets. Only the salt remained.
- The most famous example of a salty lake that is only getting saltier is the Dead Sea, between Israel and Jordan. The Dead Sea is one of the saltiest natural bodies of water on Earth.
- Water flowing to the Aral Sea was diverted to irrigate crops in Kazakhstan and Uzbekistan. So why are some fertilized, agricultural areas actually suffering as a result of the diversion? Read through our media spotlight “Disappearing Lake” for some help.
- The disappearing lake has left salt flats in its wake. “In some places in the eastern seabed,” the spotlight says, “salt flats spread for more than 100 kilometers (62 miles). Winds pick up the salt and deposit it over agricultural lands, spoiling some of the fertilized, irrigated soil. More than 40 million metric tons of dried salt have been swept into agricultural lands.”
- Have other bodies of water been “dried up” due to human impact?
- Can we do anything to preserve the Aral Sea?
- Yes—by not buying Uzbek cotton and demanding that clothing manufacturers and retailers don’t sell it. Read this Guardian story to understand how the fashion industry, child slavery, and environmental devastation are all interconnected. In short: “The environmental impact of losing the Aral Sea is not yet known, what we do know is that the cotton that destroyed it, is cotton picked by forced labour and destined for [Western] shops.”
NG Media Spotlight: Disappearing Lake
NG Encyclopedic Entry: basin (page 2: endorheic basin)
Wikipedia article: Salar de Uyuni (salt flat)
NG Photo: Dead Sea
NG Photo Gallery: 8 Mighty Rivers Run Dry From Overuse
USGS Photo Gallery: Lake Chad, West Africa
The Guardian article: Cotton production linked to images of the dried up Aral Sea basin