Why is it that most deserts are located near the west coasts of continents? --- Kaushik, Chennai, India
Marshall Brain Answers:
Here is a map that shows where the planet's major deserts are located:
When you look at the map you can see that the deserts of North America and South America are indeed located on the west coasts. This has to do with the prevailing winds and the fact that both continents have high mountain ranges on the west side. In North America it is the Rocky Mountains and in South America it is the Andes. Air coming from the west has to rise to high altitudes to get over the mountains (causing the moisture to condense out), and that leaves a rain shadow on the eastern side.
On the other hand, the Sahara crosses a whole continent and extends to the east. In Australia, most of the continent is desert to some degree. In China the deserts tend to be in the middle of a large continents. See also: