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Sand Dunes by Victoria and Alejandra

It's an ocean of sand here at the Guadalupe-Nipomo Sand Dunes. Just like us, sand dunes come in different shapes and sizes. One of the coolest differences between sand dunes is the plants that grow on them, but we didn't understand why some dunes are full of plants and others aren't. So we decided to investigate for ourselves!

What did we do?
We hiked over three kinds of dunes. The fore dunes are right next to the ocean. The scrub dunes are about a mile inland. Two miles inland are the big, active dunes. At each dune, we estimated the size, counted the plants growing on it and measured moisture in the sand with a portable measuring tool. We wrote down our data and made a graph.

What did we find out?
The fore dunes had the most moisture and the second highest number of plants. Even though fore dunes have a lot of moisture, they're blasted by ocean winds and storms that disturb both the plants and the dunes. The scrub dunes had the second highest level of moisture and the most plants. Since they're a mile away from the ocean, they have moisture, but are removed enough to avoid all the crazy, blowing weather. The active dunes had the least moisture and no plants at all. Their sand is so dry that winds push them around and their shape changes every few days.

What can you do?
  • Erosion happens when earth materials are removed and transported by natural agent, like glaciers, wind, water and tornados. Weathering is similar to erosion because it breaks up the rocks, but weathering doesn't move any of these materials. Now that you know these definitions, search the outdoors for one example of erosion and another example of weathering. What does each object look and feel like? How far apart did you find them? How are they the same? How do they differ?
  • Find an example of erosion in your town. Try a river bank. Now, do some historical detective work. Interview adults who have lived there for many years and ask questions like: What did this area used to look like? How long did it take to look the way it does? What factors contributed to the erosion? Record what you find and use your findings to create a drawing of what the bank originally looked like.
  • Take a walk on the beach. Collect samples of materials you find such as pebbles, sand, debris, seaweed, driftwood and other items. Keep these samples and record your observations. Take the same walk a month later. Do you find different things? Why? How have humans changed the beach? Can you see evidence of erosion?

    Related Link: The Dune Center
  • Use this earth science investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!
more resources
More on Weathering/Erosion

Go to the DFTV Boards, and tell us about your science investigation.
whiz quiz
How large is the average meteor?

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