Week 19: We learned how rivers move sediment and boulders with three simple experiments.
When a river is shallow and slow the water can move small bits of dirt, but when a river is full, the raging water can be strong enough to move boulders. Packed within the story in the book Rocks, rivers & the changing earth,: A first book about geology are suggestions for many simple experiments.
Flood: Wrestling With The Mississippi was also read as part of this study. This book explained the history of the levee system along the Mississippi River and how people worked together to fight the unending rains of 1993.
River Bed Sediment
To learn how water moves sediment in a river bed we first made a riverbed channel out of a piece of cardboard folded into U-shape.
Next the entire contents of the watering can were emptied into the channel resulting in the rocks and all the sediment flowing into the basin. This signifies a flood situation where the river is strong enough to move large boulders.
After this simple experiment, we learned how material settles on the bottom of a slow moving river.
Settling Trail Mix - The smallest materials sink to the bottom.
To reinforce the concept of the smallest materials settling on the bottom and biggest settling on the top, we made trail mix and shook it up.
If you haven't seen our other science units make sure to check them out. There is a complete Cell and Human Body Unit Study to go with this nearly complete Earth Science Unit. They can all be found on the Science Page.
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