An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
243
The Amazon rainforest produces more than 20% the world's oxygen supply.
182
In one day, a full grown redwood tree expels more than 2 tons of water through its leaves.
56
The North Atlantic gets 2.5 centimetres (1in) wider every year.
119
Australia's Great Barrier Reef is 1,250 miles long!
45
The Atlantic Ocean is saltier than the Pacific Ocean.
54
The warmest temperature ever recorded on Antarctica was 3 degrees F.
175
The water of the Antarctica is so cold that nothing can rot there.
334