An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
243
Venice Island was built on a foundation of tree trunks. 1200 years later, those same trunks still support almost all of central Venice.
8
If Manhattan had the same population density as Alaska, there would only be 15 people living there.
138
10 of the tributaries flowing into the Amazon river are as big as the Mississippi river.
41
Forest fires move faster uphill than downhill.
52
Check your map! The Pacific entrance of the Panama Canal is farther East than the Atlantic entrance.
40
Every year, Alaska has about 5,000 earthquakes.
31