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Cape Point
However a very significant fraction, called the Agulhas Retroflexion leaks warm water in
eddies up to a depth of 2,000 meters and this flows up to join the Atlantic circulation called
the Atlantic Meridional Overturning Circulation (AMOC) and in turn pumps warm water up to
the Artic water circulation influencing Artic temperatures.
The Kalahari Desert covers 350,000 sq. miles and is part of the greater Kalahari basin of
2.5 million sq. miles and the inland Lake Makgadikgadi that once covered 106,000 sq. miles
during a wetter period. On the other hand, one of the worst droughts struck 16 to 17 thousand
years ago, the so called “H1-megadrought” when Lake Victoria, Africa's largest tropical lake,
dried out and the Nile River was blocked by sand dams. The monsoons also failed and it was
believed it was related to the Heinrich event when icebergs poured into the north Atlantic,
disrupting ocean flow patterns. About 14 thousand years ago rainfall increased and the African
lakes were up to 200m deeper than now and for example Lake Turkana flowed into the Nile.
Then, about 12,700 to 11,700 years ago during the Younger Dryas the conditions again become
drier and then again in 11,700 years ago another moist phase again began lasting to 7,500 years
ago. The current desiccation phase started about 5,500 years ago. Many believe these climate
changes influenced the African domestication of flat backed hump-less N'Dama cattle from
African aurochs about 10,000 years ago at Bir Kiseiba, rather than domestication from humped
south Asian zebu (Brahmin) cattle. It is speculated this was to turn dirty water into drinkable
milk or blood. Climate change will continue to influence, particularly agricultural,
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