As eons pass, continents and other land masses
collide, break apart, and drift across the planet
on the fiery mantle beneath, opening and closing
oceans along the way. Subsequently, their relative
position to the equator, the poles, and each other
changes over long periods of time. For instance,
Africas Sahara Desert once lay at the South
Pole while the equator ran diagonally across North
Scientists hypothesize that North and South America
must have been 6,000 miles apart 450 million years
ago. Yet, 250 million years later, they lay locked
together as part of Pangea, the great supercontinent.
Then a great rift developed between them and todays
Atlantic Ocean began to open. [The plates dont
move very quickly. But consider this: Two inches
per year - a typical speed - adds up to 30 miles
in one million years. It took only 150 million
years for a slight fracture in an ancient continent
to turn into todays Atlantic Ocean].
While the Atlantic Ocean opened, the Pacific
began to shrink. The Americas slid west while
the huge Eurasian plate and Australia drifted
east along with India, which broke away from southern
Africa to begin its long journey north.
Some 20 million years later India collided with
southern Eurasia, thrusting up their crustal borders,
marking the birth of the majestic Himalayan mountain
range. And long ago Ireland and northern Scotland
were part of North America, attached to Newfoundland,
while part of Florida lay in Africa.
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