Sand Dunes

Sand dunes are hills made of sand that have been piled up by the wind. They are found in deserts and along beaches. Dunes can be small or very large. They are always changing shape because the wind keeps blowing the sand around.

How Sand Dunes Form

Wind blows loose sand across the ground. When the sand hits something like a rock or a plant, it starts to pile up. More sand blows onto the pile and the dune grows taller. The wind pushes sand up one side and it slides down the other side.

Types of Sand Dunes

There are different shapes of dunes. Crescent dunes look like the letter C. Star dunes have ridges going out in many directions. Linear dunes are long and straight. The shape depends on how much sand there is and which way the wind blows.

Fun Facts

• The tallest sand dune in the world is in the Namib Desert and stands over 1,000 feet high.
• Sand dunes can move across the land as wind blows sand from one side to the other.
• Great Sand Dunes National Park in Colorado has dunes that are over 700 feet tall.

Did You Know?

Some sand dunes make a booming or singing sound when the sand slides down them!