What is weathering, erosion, and deposition? Margaret heads to Lake Erie to explain the difference between these three environmental impacts.
Class Discussion Questions:
1) Create a Venn diagram comparing weathering, deposition, and erosion.
2) Is weathering, deposition, and erosion good or bad? (Or both??) Justify your response.
Read the Script:
[Margaret] In the summer, I like to head to the shores of Lake Erie. No, not for a dip in the water. For a walk along the beach and a hunt for sea glass. Unfortunately, I haven't had much luck. I'm more likely to leave with some smooth pebbles than a pretty piece of glass. But still, Lake Erie is a great spot to learn about weathering, erosion, and deposition.
Let's start with weathering. That's the breaking down of rocks, soils, and other substances into smaller pieces, especially by wind and water.
So those pebbles I found, they probably weren't always so small or so smooth. Being knocked around by the water and pushed by waves into one another resulted in their rough edges being smoothed away. Voila, weathering.
Zoom out from the pebbles and we can see erosion in action. Erosion is a process of moving rocks and soil to a new location. As the waves from Lake Erie hit the shore, they start to knock down soft soil and pull it away from its original place.
Erosion is a particularly dangerous process for folks whose homes are located on the shore. Gravity is happy to lend a hand and as the soil gets pulled away by the water, large chunks of the shoreline can tumble right into the lake.
To keep this from happening, some communities along Lake Erie have installed what are called break walls or breakwaters. Those are usually large piles of rock that are not as easy for the lake to erode.
Of course, all of Lake Erie is an example of erosion. During the Ice Age, the glacier that covered Ohio scooped right through the area, leaving the lake behind. You can see good evidence of it over on Kelleys Island. Check out these grooves left behind. Erosion is a pretty destructive process.
Now where there's erosion, somewhere else there has to be deposition. That is when the soil, rocks, and minerals that were eroded are dropped off, creating new landforms. It's a constructive process.
So the sand on the beach is a great example. It was brought to shore by the water, making a beach and some dunes. Lots of other areas of Ohio have rich soil good for farming because it was deposited there by Ice Age glaciers. All three of these processes, weathering, erosion, and deposition, continuously tear down and build up Earth's surface.
But enough with the lessons. I wanna see if I can find some of that beach glass.