An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
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Due to gravitational effects, you weigh slightly less when the moon is directly overhead.
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The names of the continents all end with the same letter with which they start, excluding the North and South infront of AmericA.
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The North Atlantic gets 2.5 centimetres (1in) wider every year.
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The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
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One cubic mile of seawater contains about 50 pounds of gold.
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