The Sahara Desert, named after the Arabic word for desert ~ sahra,
is the second largest desert in the world covering an area of some
3,630,000 square miles with sand dunes 590 feet tall, the only
larger desert being in Antarctica.
To explain, deserts are defined by the amount of precipitation (rain, snow, mist, and fog) they receive. A region that experiences very little precipitation is categorized as a desert and Antarctica fits this criterion perfectly because the average yearly rainfall at the South Pole over the past 30 years has been a mere 10 mm (0.4 in.) Uniquely, unlike most deserts that cover only part of a continent, the Antarctic Polar Desert spans the entire landmass.
As large as Europe,
the Sahara stretches 2,983 miles from the Red Sea to the Atlantic
Ocean and 1118 miles from north to south encompassing the Western
Sahara, Morocco, Mauritania, Mali, Tunisia, Algeria, Libya, Niger,
Egypt, Chad, the Sudan, Somalia and Eritrea. As its reaches its
southernmost limits, the Sahara becomes the Sahel, a semi-arid
savannah.
Fossil formation
founds in the Sahara indicate that much of the area was once wet
and home to an abundance of life with animal and human remains
found at over 150 sites, and the weathering of the Sphinx in
Egypt, once believed to be from sandstorms, but now widely
believed to be from rainfall, provides further evidence for this.
However, from around 8000 to 4000 years ago the area underwent
change from a landscape of grasslands and shrubs to the
landscape we now see. Some identify the cause of this change
being a shift in the earth's tilt from 24.14 degrees 9000 years
ago to 23.45 degrees today.
This dryness and
heat (the highest temperature ever recorded being in Aziziyah,
Libya 136f or 58c), make most of the Sahara
uninhabitable apart from the nomads who frequent its many oases.
The general population of the Sahara is believed to be around
four million, however most of these live in less harsh areas on
the borders of the desert in Egypt, Libya, Algeria and
Mauritania.
With growing desertification southwards, the desert,
which has a history of expanding and shrinking, is now
encroaching on communities in Niger and elsewhere promoting the
idea of the Great Green Wall, a man made strip of land some
nine miles wide that is to be constructed from Dakar to
Eritrea across Africa, to hold back this desertification.
Find out more about the Sahara Desert in the video above, check out pictures of the Sahara Desert above.
