Playas

From Friends of the Black Rock High Rock Wiki
Revision as of 18:57, 3 January 2008 by Bc (talk | contribs) (added links)
Jump to navigation Jump to search


on aeolian research - the scientific study of the detachment, transport, and deposition of sediments by wind. Aeolian research spans a broad array of disciplines and may include: the study of the physics of blowing sand, dust, and other granular material (i.e., saltation, suspension, creep and abrasion); the study of geomorphic processes in arid environments and associated aeolian landforms, deposits, and sedimentary features; the study of wind erosion and its control by tillage, cover crops, shelterbelts, and other management practices; and the study of mineral dust, dust emissions, atmospheric transport and the effects of fine particulate matter on climate, weather, and air quality.



In the Desert Southwest, 'playa' also refers to one of the many vast lakebeds that fill the valleys. These were formed during a wetter time, during the ice ages. As the climate dried, the lakes gradually disappeared, leaving only a flat layer of white saline ground. Many of these lakebeds will fill with a very shallow layer of water after storms. Sometimes the layer will be so thin that it moves from one side of the playa to the other depending on the wind. Other times they can be several feet deep and many miles across. Because these playas were once much larger lakes, often they are surrounded by old 'beaches' and terraces which are often hundreds of feet above the surface of the valley and encircle the playas like bathtub rings.

Playas are abundant in the Mojave Desert, and i'm sure in other deserts of the world, albeit under different names. One of the largest playas around is the Bonneville Salt Flats, which is used for racing extremely fast cars because it is perfectly flat. Some playas are mined for borax, salt, or other minerals. In the Death Valley area, there is a playa called 'the racetrack' where rocks mysteriously move around the surface, leaving long tracks in the mud. Another playa in the area has crystalized into bizarre formations and is now called the devil's golf course. A playa formed in the place of Owens Lake in recorded history as Los Angeles dried up the Owens River. Mono Lake barely avoided the same fate.