What are sand dunes?

Sand dunes are big hills made of sand that move and change shape over time.

Imagine you're playing on a beach with your friend. You both run into the water, splash around, and then run back to the shore. The waves push sand forward, and when you step on it, the sand shifts under your feet. That’s like how sand dunes work, but instead of just one person or wave doing it, it's wind that does all the pushing.

The wind is like a big invisible friend who keeps moving the sand around. When the wind blows, it carries tiny grains of sand with it. These grains land on a hill made of sand, and poof! The hill grows taller or changes shape.

Sometimes, when the wind stops, the sand settles down, just like how you rest after playing all day. But if the wind starts again, it picks up more sand and moves the dune somewhere else, kind of like a dance between the wind and the sand.

Some sand dunes are smooth, while others have ridges or even look like waves. They can be as small as your toy castle or as big as a mountain, depending on how much sand is there and how strong the wind is!

So next time you're at the beach, imagine that you're seeing a little part of the sand dunes world, just waiting for the wind to bring them to life!