A barchan, or barchan dune, is a crescent-shaped sand dune that forms when the wind in a desert region blows mostly from one direction. The horns of the crescent shape point in the direction that the prevailing wind blows.

Barchan dunes can be up to 10 meters high - that is about 30 feet. They are notorious for migrating - moving position gradually with the winds.

There are sometimes huge expanses of barchan dunes in coastal deserts, like in Peru, Namibia, and Morocco.

Log in or register to write something here or to contact authors.