WORLD HISTORY

Detailed explanation-1: -Ergs, which cover 20 percent of the Sahara, are sand dunes that stretch for hundreds of kilometers at heights of more than 300 meters (1, 000 feet). Ergs cover most of Algeria and Libya and parts of Mali and Nigeria.

Detailed explanation-2: -the Living Africa: the land-Sahara Desert-Physical Features. The Sahara’s topographical features include shallow basins, large oasis depressions, serirs or regs (gravel-covered plains), plateaus, mountains, sand sheets, dunes and sand seas (ergs).

Detailed explanation-3: -However, around 5, 500 years ago there was a sudden shift in climate in northern Africa leading to rapid acidification of the area. What was once a tropical, wet, and thriving environment suddenly turned into the desolate desert we see today.

Detailed explanation-4: -The Sahara Desert, the largest of its kind anywhere in the world, is over 10.4 million km2 n North to south is approx. 1800 kms and east-west is 5600km. In terms of structure and relief features, Africa appears to be different from the other continents.

Detailed explanation-5: -The Sahara is bordered in the west by the Atlantic Ocean, in the north by the Atlas Mountains and Mediterranean Sea, in the east by the Red Sea, and in the south by the Sahel-a semiarid region that forms a transitional zone between the Sahara to the north and the belt of humid savannas to the south.