The Sahara is the largest hot desert in the world, and the third largest desert behind Antarctica and the Arctic, which are both cold deserts. The Sahara is one of the harshest environments on Earth, covering 3.6 million square miles (9.4 million square kilometers), nearly a third of the African continent, about the size of the United States (including Alaska and Hawaii).
The Sahara is bordered by the Atlantic Ocean on the west, the Red Sea on the east, the Mediterranean Sea on the north and the Sahel Savannah on the south. The enormous desert spans 11 countries: Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia.
The Sahara desert has a variety of land features, but is most famous for the sand dune fields that are often depicted in movies. The dunes can reach almost 600 feet (183 meters) high but they cover only about 15 percent of the entire desert. Other topographical features include mountains, plateaus, sand- and gravel-covered plains, salt flats, basins and depressions. Mount Koussi, an extinct volcano in Chad, is the highest point in the Sahara at 11,204 feet (3,415 m), and the Qattara Depression in Egypt is the Saraha’s deepest point, at 436 feet (133 m) below sea level.
Although water is scarce across the entire region, the Sahara contains two permanent rivers (the Nile and the Niger), at least 20 seasonal lakes and huge aquifers, which are the primary sources of water in the more than 90 major desert oases. Water management authorities once feared the aquifers in the Sahara would soon dry up due to overuse, but a study published in the journal Geophysical Research Letters in 2013, discovered that the “fossil” (nonrenewable) aquifers were still being fed via rain and runoff.
Credit : Live Science
Picture Credit : Google
