The earth covered with sands suffering from the heated sunshine and strong dry winds – such many imagine the desert. Very few people know that on the planet there are not only sandy deserts.
1. Area
On Earth of the desert occupy more than 35 million sq.km that sorazmerimo with the territory of Africa.
2. Life minimum
The desert – the place with a minute quantity of precipitation, high speed of evaporation of moisture, poor vegetation and fauna. In some places the flora and fauna are absent at all.
3. Such different deserts
Distinguish not only sandy, but also polar, stony and saline deserts. So, the world's largest salt desert is Uyuni that in Bolivia. There annually extract more than 20 thousand tons of salt. Antarctica is the desert, only polar too. It is considered the driest, windy and cold place on Earth.
4. Dry and very dry
It is accepted to distinguish superdroughty and droughty deserts. In the first in a year less than 100 mm of precipitation drop out (Namib in Namibia), and secondly – this indicator fluctuates from 100 to 250 mm (Kalakhari in South Africa). The center of any desert always is superdroughty.
5. High evaporation
Rains in deserts are rare. And in some places, water evaporates with such high speed that rain drops just do not reach the Earth's surface.
6. Extreme temperatures
The climate of the desert differs depending on its height and distance to the ocean or the sea. So, the Sahara which is at small height and near the equator breaks temperature records: in the summer afternoon the thermometer shows more than +50 wasps, at the same time sand is heated up to +80 wasps at all.
The big difference of daily temperatures is characteristic of deserts. So, in the Sahara at night stem of thermometer can fall below zero, hoarfrost sometimes drops out. So sharp difference is explained by big intensity of the sun and the minimum air moisture content which keeps heat.
7. Reconquest of lands
Deserts constantly expand. Annually they win on average from 7 to 10 m of the earth.
8. Unique desert
In Brazil there is very unusual Lensoys-Maranyensis Desert which is cut generously up by lagoons with transparent water. The combination of sandy dunes and turquoise water represents a delightful show.
9. The smallest
Karcross – the dwarf among deserts. It is in Canada. Its area is only 2.6 sq.km.
10. The driest
In the Chilean Atacama Desert no more than 1 mm of precipitation in a year drop out on average. On some sites the rain drops out time in several years. It does her by the dry desert of the world.
11. Mirages
Mirage – the frequent phenomenon in the desert. Can seem to the person that the unruffled surface of a reservoir in the distance is seen, but in reality there is nothing, except sand. It is optical illusion which is caused by uneven reflection of light different layers of air.