The children experience wind erosion in a hands-on investigation. The class will make a sand tower and then the students will take turns blowing through straws and observe the changes. They will take scientific notes on the process. To explain the erosion process they watch a short movie and then explain to their partner about erosion.
NGSS/Common Core Connections
In the NGSS the children are expected to provide evidence that Earth events can occur quickly or slowly. In order to understand these events and the speed at which they occur, students must understand the processes themselves. In this activity, they will be representing wind erosion, which is usually a slow process in land formation. The cross-cutting concept that some things stay the same, while others change will also be practiced as the children observe "wind" eroding the land.
While doing this investigation, they will be using sand to model the land and blowing through a straw to model the wind, which will help them to understand models, as well. In addition, another NGSS standard is for the children to know that both wind and water can shape the land. They will be interpreting the information observed to help them construct explanations of which will occur quicker, wind or water erosion. During this investigation, the children will also be obtaining, evaluating and communicating information.
In advance, I moisten the sand VERY slightly. I moisten it enough that it turns a bit darker color. This will make it keep its form when the container of sand is turned over. However, it is best to keep the sand on the drier side so the effects of erosion will be more visible.
To begin the lesson, I show children a few photos that show how wind has changed the land and created some really interesting formations. I want to get them interested in wind erosion and these photos will pique their curiosity about the world around them.
I want you to take a close look at each of these photos. They were all made by wind. How could wind possibly create these formations? How do you think this happens?
Asking a few questions will start them thinking about wind erosion. As adults, we don't often think about wind changing the land, but it is happening everyday. Most children are aware of storms that create a large amount of damaging wind, such as tornadoes, but they are totally unaware that wind can cause these variations in landforms over large spans of time. So showing them the photos and discussing gets them thinking about wind at a whole different level.
To explore the idea of how wind erosion can change land, the children are going to make observations of these changes land by doing a hands-on investigation. We are working towards the standard which is that wind and water can change the land.
I pack the sand in a large Cool-Whip container. I flip the container of sand over in a large bin (see before photo). If it doesn't totally stay intact, that's OK. The children will be able to see the effects regardless of the shape. I hand an erosion observation recording sheet to each of the children.
Today we are going to be investigating how wind can change the land. I have made a hill with sand. You are going to get to take a turn making "wind" by blowing into a straw. What do you think will happen when we blow onto the sand hill? What are your predictions?
I then put the container down at eye level so they can all see how my sand hill looks at the beginning of this investigation.
Scientists make good observations. I would like you to take a close look at the sand hill. What do you see? What observations can you make? You should observe very closely and look at every detail since there will be changes during this investigation It will be your job to see the changes as our investigation is underway. At the end of the investigation, you will be depending on each of your notes to help you draw conclusions. So your notes and drawings should be very detailed.
The children draw a diagram in the first box. They also write their observations and draw how it looks and make a few observational notes on the lines below.
Then I have about half of the children come up, one at a time, and blow into their straw about 5-8 times to create "wind" blowing on the hill. The child blowing puts goggles on to make sure the sand does not go into his/her eyes (see photo). Everyone watches and makes observations of the changes that occur in the mound of sand in the second box. (Of course, the straw they have used it placed in the garbage can and the next child gets a new one).
Then we repeat the process with the other students (see after photo). I would have liked there to be more of a change to notice, so I plan on making some changes for next year (see reflection for more details). When they all have had a chance, the children write down the ending result in the last box and write observational notes.
What did you notice? Were there any changes? Why do you think those changes took place?
I would like them to notice that wind has changed the shape of our mound of sand. They should be able to verbalize that the sand now has crevices and is a bit smaller than it was when we started. Knowing this, the children can then generalize that wind can change our Earth.
To explain wind and water erosion, we watch a 4.5 minute video titled Slow Land Changes. The beginning of the video discusses weathering. Then it shows how wind, water and other forces cause erosion.
When the video is over, we specifically discuss wind erosion. I try to get the children to relate what we have just learned to our investigation.
What did you notice about wind erosion in our investigation? What is happening to the sand?
To elaborate on the concept of wind erosion, I relate what we have learned in this lesson to our previous lesson on water erosion. Then I have the children discuss as a whole group discussion how the rate of change of wind erosion would compare that of water erosion.
You have learned that wind and water can change the land. Think about both of our investigations, which one did you see quicker changes? In nature, which one do you think creates larger changes over a long period of time? Why do you think this way?
Asking these questions helps them to form interpret our observations that we have made with both forms of erosion and then construct explanations. Watch this video and this one to see how the children are constructing explanations of why they think water would create more changes over time.
To wrap-up our lesson, I have the children do a quick review of wind erosion.
I would like you to explain wind erosion to your turn and talk partner. Explain how it can help shape the land.
Having the children do a final explanation helps them tie-in all of the concepts that we have learned today about wind erosion. As they are explaining it to their partner, I walk around and listen to see if they have the main concept that wind can help change land. They should be able to explain that wind slowly blows particles away to a different sport which helps to create this change.