Discover

(Redirected from Alkali flat)




A 'playa'; also known as an 'alkali flat', 'sabkha', or 'salt flat'; is a dry lakebed, generally the shore of, or a remnant of, an endorheic lake. Such flats consist of fine-grained sediments infused with alkali salts. Their surface is generally very dry, hard and smooth in the summer months, but wet and very soft in the winter months. While the playa itself will be devoid of vegetation, they are commonly ringed by shadscale, saltbrush and other salt-tolerant plants that provide critical winter fodder for livestock and other herbivores.
Another type of playa is a 'salina'. They are very rare, with only 3 on Earth. A salina flat occurs below sea level, behind a rocky, non-porous beach that salt water can easily penetrate through to mix with fresh water from the ground or other sources.
Many playas contain shallow lakes in the winter, especially during wet years. If the layer of water is thin and is moved around the playa by the wind, an exceedingly hard and smooth surface can develop. Thicker layers of water can result in a "cracked-mud" surface and "teepee" structure desiccation features. Very little water can result in dune formation.
The extremely flat, smooth, and hard surfaces of playas make them ideal surfaces for motor vehicles and bicycles. Large-sized playas are further excellent spots for pursuing land speed records, as the smoothness of the surface allows low-clearance vehicles to travel very fast without risk of disruption by surface irregularities, and the course of travel does not need to be too precise to avoid obstacles. The playas at Bonneville Salt Flats in Utah and Black Rock Desert in Nevada have both been used for setting land speed records.
Salar de Uyuni in Bolivia, near Potosí, is the largest salt flat in the world at 4,085 square miles (10,582 square km), which is about 25 times bigger than the Bonneville Salt Flats.

Contents

Terminology

External links

See also

Terminology

The Spanish word ''playa'' () literally means "beach". Alkali flats are known by this name in some parts of Mexico and the western United States (pronounced ). On the Llano Estacado and other parts of the Southern High Plains, ''playa'' refers to a playa lake, a smaller seasonal depression.
In Arabic, an alkali flat is called a ''sabkha'' (also spelled ''sabkhah'','subkha', sometimes ''sebkha'') or ''shott''.

External links

★ The Bibliography of Aeolian Research

See also

★ Salt lake

★ Salt pan