Sahara - geography.

Sahara - geography. Sahara, great desert area, northern Africa, the western portion of the broad belt of arid land that extends from the Atlantic Ocean eastward past the Red Sea to Iraq. The entire desert, the largest in the world, is about 1,610 km (about 1,000 mi) wide and about 5,150 km (about 3,200 mi) long from east to west. The total area of the Sahara is more than 9.1 million sq km (more than 3.5 million sq mi), of which some 207,000 sq km (some 80,000 sq mi) consist of partially fertile oases. The boundaries of the Sahara are the Atlantic Ocean on the west, the Atlas Mountains and the Mediterranean Sea on the north, the Red Sea and Egypt on the east, and the Sudan and the valley of the Niger River on the south. The boundaries, however, are not clearly defined and have been shifting for millennia. The Sahara was once a fertile&l...