Approximately a third of the Earth's land surface is made up of some kind of desert with very little rainfall and vegetation. Deserts are very dry and hot, but at some points experience a cold front. Deserts vary in several different ways. Some contain vast areas of sand, rocks or gravel with few plants. Severe winds blow in and out of the deserts transporting valuable mineral deposits, thus leaving behind preserved fossils. Sand dunes are very prominent in deserts and there are several different types depending on the wind patterns. Plant life varies as well.
Winds play a big role in the desert atmosphere. They may be seasonal, sporadic or even daily. They range from gentle breezes to violent gusts at speeds as high as 300 k/hr. Deserts are formed by global circulation patterns. They are usually found close to the north and south poles and the equator. There are deserts not only on the Earth, but also on other planets including mars with a surface of a desert all around.
Deserts come in all different shapes and sizes. They are
The Coastal Desert, which is found on the western edges of the continent. They are generally by cold ocean currents by the coast. These deserts are less stable than other deserts because winter fogs produce cold currents and block solar heat. One of the Earth's driest deserts is the Atacama of South America, measuring 1 millimeter or more of rain. Crescent shaped dunes are common in these deserts. Monsoon deserts develop in response to changing temperature between continents and oceans. Lastly, the Polar deserts are areas with annual precipitation less than 250 millimeters and has very cold weather during the warmest month. The soil found on these deserts consists of bedrock or gravel. Sand dunes are rarely found in these deserts, but there is quite a bit of snow that falls in highly precipitated areas.
With strong winds and several different patterns dunes are created on the desert surfaces. The most common dune on the Earth is the transverse or bachan dune. They are generally wider than they are long. They form when winds blow in one direction. Seve
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