What is a Desert? A desert is a landscape or region that receives very little precipitation - less than 250 mm per year (about ten inches). Approximately 1/3 of Earth's land surface is a desert. There are four different types of deserts based upon their geographic situation:

  • 1) polar deserts;
  • 2) subtropical deserts,
  • 3) cold winter deserts,
  • 4) cool coastal deserts.

The two largest deserts on Earth are in the polar areas. The Antarctic Polar Desert covers the continent of Antarctica and has a size of about 5.5 million square miles. The second-largest desert is the Arctic Polar Desert. It extends over parts of Alaska, Canada, Greenland, Iceland, Norway, Sweden, Finland and Russia. It has a surface area of about 5.4 million square miles.

More Info: geology.com