Ed­u­ca­tion: hot deserts

Deserts make up one-third of Earth’s to­tal land­mass, and the hot ones form 20% of these CLI­MATE LO­CA­TION

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ADESERT is a rocky, sandy area of land that’s dry and in­hos­pitable. It’s usu­ally not in­hab­ited by peo­ple. The plant and an­i­mal life in deserts have adapted to sur­vive with lit­tle wa­ter. There are four types of desert – hot, cold, semi­arid and coastal. Let’s take a look at hot deserts, which in­clude sev­eral of the most bar­ren places on Earth. Hot deserts are aptly named be­cause in these places the tem­per­a­ture can soar above 40°C in sum­mer. At night the tem­per­a­ture can drop to below freez­ing point.

Hot deserts are also ex­tremely dry, with less than 250mm of rain­fall a year.

They have two dis­tinct sea­sons – sum­mer (with av­er­age day­time tem­per­a­tures of 35-40°C) and win­ter (20-30°C dur­ing the day). Hot deserts are found close to the Trop­ics of Can­cer and Capricorn. These two cir­cu­lar lines oc­cur at the same lat­i­tude (23,5°) north and south of the equa­tor. The equa­tor is an imag­i­nary line cir­cling the mid­dle of the globe (0°), and is the same dis­tance from the North and South Poles.

In the in­tertrop­i­cal zone be­tween the Trop­ics of Can­cer and Capricorn the sun is at its fiercest and the dif­fer­ence be­tween the length of days and nights is the small­est. Hot deserts de­velop at these lat­i­tudes, where the air is gen­er­ally calm and the at­mos­phere is sta­ble.

The largest hot desert is the Sa­hara in North Africa. It’s lo­cated along the Tropic of Can­cer and stretches all the way from west to east across the African con­ti­nent.

Other hot deserts along this tropic in­clude the Libyan and Nu­bian deserts in

North Africa; the Danakil and Grand Bara deserts in the Horn of Africa; the Dasht-e Lut and Dasht-e Kavir in Iran, as well as the Ara­bian and Syr­ian deserts in the Mid­dle East; the Thar Desert across In­dia and Pak­istan; and the Mo­jave, Sono­ran and Chi­huahuan deserts in North Amer­ica.

Along the Tropic of Capricorn in South­ern Africa you find the Namib and Kala­hari deserts while the Simp­son and Great Vic­to­ria deserts are lo­cated in Aus­tralia.

PLANT AND AN­I­MAL LIFE

Deserts get lit­tle rain, and rain­fall pat­terns are highly un­pre­dictable. Rain storms are rare and long pe­ri­ods of drought of­ten oc­cur. Be­cause of the low pre­cip­i­ta­tion, an­i­mal life is quite sparse.

Al­though many peo­ple think desert soils are in­fer­tile this isn’t nec­es­sar­ily the case – af­ter a good down­pour, large parts of a desert can sud­denly be cov­ered in plants. But desert soil can’t re­tain wa­ter for long so veg­e­ta­tion quickly dies again. Desert plants and an­i­mals have adapted to cope with these cy­cles of abun­dance and scarcity.

The most ex­treme heat con­di­tions on Earth (higher than 50°C) usu­ally oc­cur in hot deserts. The high­est tem­per­a­ture ever recorded was 56,7°C, in Death Val­ley, Cal­i­for­nia, on 10 July 1913. Phew!Valle de la Luna (Val­ley of the Moon) in Chile’s Ata­cama Desert is the world’s dri­est hot desert.

Be­douin peo­ple in the Sa­hara use mod­ern tech­nol­ogy but still rely on their camels. A San man in the Kala­hari drinks wa­ter drawn from a bulb plant.

Cacti ward off an­i­mals with their sharp spines but the great horned owl (Bubo vir­gini­anus) has over­come these bar­ri­ers and makes its nest in the saguaro cac­tus of the Sono­ran desert in North Amer­ica.The meerkats of the Kala­hari Desert make un­der­ground bur­rows where they shel­ter from the heat.

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