Every year, Alaska has about 5,000 earthquakes.
31
The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
63
Check your map! Virginia extends farther west than West Virginia.
67
A volcano has enough power to shoot ash as high as 50 km into the atmosphere.
59
The Sahara desert expands at about 1km per month.
90
