The Physics of Blown Sand and Desert Dunes
Have you ever been to a playground with a sandbox? Just like how you can make designs and shapes in the sand by building with it or digging certain spots, the wind can also shape sand in big, open spaces like deserts.
When the wind blows, it picks up tiny grains of sand and carries them through the air. These grains collide with each other and form clusters, called saltation. The stronger the wind, the higher the sand travels before falling back down to the ground.
As the sand grains bounce along the ground, they create ripples and waves that can eventually turn into bigger and bigger hills of sand. These hills are called dunes.
The shape and size of these dunes depend on how much wind there is, which way the wind is blowing, and the size of the sand grains. Bigger grains can form steeper, more angular dunes, while smaller grains will form dunes that are smoother and less steep.
So, next time you're playing in the sandbox, remember that the same physics is at work in the vast deserts around the world!
When the wind blows, it picks up tiny grains of sand and carries them through the air. These grains collide with each other and form clusters, called saltation. The stronger the wind, the higher the sand travels before falling back down to the ground.
As the sand grains bounce along the ground, they create ripples and waves that can eventually turn into bigger and bigger hills of sand. These hills are called dunes.
The shape and size of these dunes depend on how much wind there is, which way the wind is blowing, and the size of the sand grains. Bigger grains can form steeper, more angular dunes, while smaller grains will form dunes that are smoother and less steep.
So, next time you're playing in the sandbox, remember that the same physics is at work in the vast deserts around the world!