300px|thumb|[[Lake Elton,
Volgograd Oblast,
Russia.]]
A
salt lake or
saline lake is a landlocked body of
water which has a concentration of
salts (mostly
sodium chloride) and other minerals significantly higher than most
lakes (often defined as at least three
grams of
salt per
liter). In some cases, salt lakes have a higher concentration of salt than sea water, but such lakes would also be termed
hypersaline lakes.
Properties
Salt lakes form when the water flowing into the lake, containing salt or minerals, cannot leave because the lake is
endorheic (terminal). The water then evaporates, leaving behind any dissolved salts and thus increasing its
salinity, making a salt lake an excellent place for salt production. High salinity will also lead to a unique flora and fauna in the lake in question; sometimes, in fact, the result may be an absence or near absence of life near the salt lake.
If the amount of water flowing into a lake is less than the amount evaporated, the lake will eventually disappear and leave a
salt flat or
playa (sometimes also referred to as
salt pan).
Notable examples
thumb|right|The Bonneville Salt Flats.
In order, the three largest salt lakes in the world are the
Caspian Sea,
Aral Sea, and
Lake Balkhash. The largest salt lake in the
Western Hemisphere, the
Great Salt Lake, is the fourth largest salt lake in the world.
The salt lake with the highest
elevation is
Namtso, and the one with the lowest elevation is the
Dead Sea, which is also the lowest exposed point on the
Earth's surface.
Some salt lakes are strictly seasonal and become arid lakebeds in the dry season. An example of this type of salt lake is the
Makgadikgadi Pans of
Botswana.
Since the 8th century, the salt of Lake
Baskunchak in Russia was mined and distributed via the
Silk Road. Nowadays the lake's salt of distinct purity (99.8 %
NaCl) covers 80 % of the country's salt production. Depending on need, about 1.5 million to 5 million tons of salt are mined per year.
See also
