Flat expanse of ground covered with salt and other minerals
This article is about the land feature. For the tidal feature, see
Salt pannes and pools.
Natural salt pans or salt flats are flat expanses of ground covered with
salt and other
minerals, usually shining white under the
sun. They are found in
deserts and are natural formations (unlike
salt evaporation ponds, which are artificial).
A salt pan forms by evaporation of a
water pool, such as a
lake or
pond. This happens in climates where the rate of water
evaporation exceeds the rate of precipitation —that is, in a desert. If the water cannot drain into the ground, it remains on the surface until it evaporates, leaving behind minerals precipitated from the salt ions
dissolved in the water. Over thousands of
years, the minerals (usually salts) accumulate on the surface.[1] These minerals reflect the sun's rays (through radiation) and often appear as white areas.
Salt pans can be dangerous. The crust of salt can conceal a
quagmire of
mud that can engulf a truck. The
Qattara Depression in the eastern
Sahara Desert contains many such traps which served as strategic barriers during
World War II.[2]
The
Salar de Uyuni in
Bolivia is the largest salt pan in the world. It contains 50% to 70% of the world's known lithium reserves.[3] The large area, clear skies, and exceptional flatness of the surface make the Salar an ideal object for calibrating the
altimeters of Earth observation satellites.[4][5]
^Borsa, A. A; et al. (2002). "GPS Survey of the salar de Uyuni, Bolivia, for Satellite Altimeter Calibration". American Geophysical Union, Fall Meeting.
Bibcode:
2002AGUFMOS52A0193B.
Briere, Peter R. (May 2002). "Playa, playa lake, sabkha: Proposed definitions for old terms". Journal of Arid Environments. 45 (1). Elsevier: 1–7.
Bibcode:
2000JArEn..45....1B.
doi:
10.1006/jare.2000.0633.