Genesis Sahara desert land is part of the Earth's surface. Barren held until the plants and animals can not survive. Or even almost uninhabitable as well. But because of the heat and sand dunes own pictures from : Http://www.danheller.com/sahara.html conditions without rainfall and hot temperatures in the desert. As a result, the relative humidity of the air above the desert. Almost zero all year round And even some of the time to be there. Rain in the desert for some time But the hot weather made the water evaporating before rain will fall. Sand, unless the rain. After falling to the sand, then the water will seep into the underground water. Oasis ( Oasis) , a source of abundant water in the deserts of the world, there are many desert of deserts, including the famous. Desert Sahara is located north of the African continent. Desert Gobi in Mongolia Desert Turkertan in Russia, Great American Desert in America. And Patagorian in Argentina, etc. The general geographic area of the desert, as with other parts of the world, there are mountains, plains and dunes ( Dune) , where the dunes are as high as 300 meters. And moving the annual rate of 10 meters. Because desert wind blows The windswept dunes. It may move up to 20 meters in one day. And when the dunes moving to anything. It also raised over it until the end. And dunes are shaped However, it depends on the dynamics between wind and sand. Still, the inclination of the dunes is never more than 32 degrees, the temperature of the air above a desert each. Normally are not equal With the desert Located anywhere in the world The almost cloudless Make the desert sun in the sky from the sun directly. The temperature of the air above the desert, so it could be up to 65 degrees Celsius. But at night The sand spit heat faster. The air temperature may drop as low as 25 degrees Celsius. The difference is huge The air temperature in the daytime and at night in the desert This causes a severe storm. The surfer desert Always find a sandstorm blows intense and frequent. In addition to temperature, then reasons Topography and location Deserts on earth, it has to determine the speed of the wind. Statistics desert wind speeds of up to 80 km per hour speed, as this can blow sand and dust to fall in Desert Storm as far away as Australia. May carry sand to fall In New Zealand, the Far 2,400 kilometers. Or sandstorm in the Sahara may carry sand to fall in Northern Europe, the comfort of images : Http://www.calacademy.org/exhibits/africa/exhibit/sahara/index.html desert Sahara , a desert territory. the most extensive in the world An area of 9.3 million square kilometers ( larger than the United States ) and located. Northern Africa Write territory west Atlantic. Eastern border the Red Sea Write northern mountains Atlas and the Mediterranean. Write south latitude 15 degrees north. The country, Tunisia, Chad Libya, Algeria, Sudan, Niger and Egypt is around. Desert air temperature in July. On average about 32 degrees Celsius. The average temperature in January. High around 20 ° C Statistics daytime maximum temperature of 57 degrees Celsius. The tallest dunes in the world is up to 465 meters. Situated in the desert Sahara , the Isaouane - N - Tifernine in Algeria weathered the storm in the Sahara , where the wind blows and the famous Sirocco and Khamsin , etc. Incidentally, this desert rain, not exceeding 25 centimeters. And intermittent rain But the fall and finish quickly. So small streams Available in a desert valley becomes a river within a few hours, the general geography of the Sahara plains. It has some high mountains such as Mt. Ahaggar at 3,300 meters. In Algeria , and in the area north of the desert to the oasis rather than the south. And water resources is a palm, olives, grapes, wheat and barley more. The water in agriculture from Mount Atlas is beyond 400 km. In this desert There is also an ancient city that was sand deposition several cities. The east side of the Nile River runs through the desert. This makes ground Has cultivated citrus fruits and cotton The Sahara is also a source of oil. It has been used in car entertainment. Arrive together, rather than using camels as in the past, one question that geologists have long suspected was dazed and Sahara have emerged. The archaeologists have unearthed seeds. Ancient in many places in the desert. The evidence shows that in the past when the 9000 - 6000 years ago, this Sahara has ever been. Gardens of Eden with green grass, trees and vegetation in abundance, but why, as of today, and today Sahara desert, with sand, but it is in the journal Geophysical Research Letters Volume 26, page 2037. M.Claussen and of the Potsdam Institute for Climate Impact Research in Germany. Provides an explanation of the causes of the condition of the Sahara 's ancient grain analysis has made him realize that the 6000 - 7000 years ago. Air Sahara warm And the Sahara Forest There are many trees But over time, the approximately 2,000 -year incident severe drought that lasted 400 years, people who settled in the Sahara to immigrants as a source of livelihood to the new Nile Basin. And causes drought levels. Mahakan that Claussen was the reason. The origins of the Earth's axis to change the tilt. Was reduced from 24.14 degrees to 23.45 degrees. Makes summer in the northern hemisphere, the temperature drops. Because sunlight strikes the Earth's surface is less. When Claussen brings cool down this summer computer input. To study the impact it will have on ocean currents and so on. Air North Africa The wind will blow from the Indian Ocean brings rain to fall on the Sahara he found. The storm brought rain, this weakness is unable to rain falling on the Sahara as much as ever. The low rainfall Trees and plants die and decompose on the forest more. The ability to retain soil moisture is even less. It's raining less and even tree death. The cycle takes 400 years to make.
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