Every year Eli and his family visit Great sand dunes desert in Colorado. Elliott notices that more dunes with varied shapes and sizes appear each year. Explain what causes this phenomenon.
Help!
I know that the wind is always different and that causes erosion.
http://www.desertusa.com/desert-activity/sand-dune-wind1.html
thank you Ms.Sue
@Your Worst Nightmare how can she if you don’t have one?
You're correct! The phenomenon you're observing, where more dunes with varied shapes and sizes appear each year, is caused by wind erosion and deposition.
Here's a step-by-step explanation of how this happens:
1. Wind erosion: The wind blows across the surface of the desert, picking up loose sand particles. This process is known as wind erosion.
2. Transport: The wind carries these sand particles and moves them across the desert. As the wind blows, it can push sand grains against larger obstacles, such as rocks or vegetation, and these obstacles act as barriers, causing the sand grains to accumulate.
3. Deposition: Eventually, the wind loses its energy or encounters obstacles that force it to slow down. As a result, it drops the sand particles it was carrying, leading to their deposition. This is where new dunes begin to form. The sand grains accumulate, layer upon layer, creating larger dunes over time.
4. Varied shapes and sizes: The shape and size of the dunes are influenced by several factors, including wind direction, wind speed, and the availability of loose sand. Different wind patterns can lead to dunes with various forms, such as crescent-shaped, linear, or star dunes. The availability of loose sand also affects dune formation and size.
So, the combination of wind erosion, transport, and deposition creates new dunes each year, and the variations in wind patterns and sand availability contribute to the unique shapes and sizes of the dunes in the Great Sand Dunes desert in Colorado.
Hope this explanation helps!