The Sahara desert expands at about 1km per month.
90
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61
Every person in the world can fit in Texas and be given over 1000 sq ft in which to live.
14
An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
243
More than 25% of the world's forests are in Siberia.
51
If Manhattan had the same population density as Alaska, there would only be 15 people living there.
138
The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
63
Israel's Dead Sea is 1,312 feet below sea level.
48