This is an activity with wind on sand. Like in a desert.
A student pair shares a tray. Each student has sand, a bottle to puff wind and a rock.
Introduce materials and activities to try to the students gradually (suggested order below). The materials invite free play of many kinds, so initially guide the students through wind erosion-related activities before opening up to free play. Discussion can come after each activity, or all at the end.
First, use the paddle to make a pile of sand, then place the rock on top, like a rock in a desert.
Use the wind from puffing the bottle to move the sand (don't use hands!)
Can you move the rock by only using wind?
Discussion: yes, by eroding sand from under the rock with wind, gravity will pull the rock downwards bit by bit.
In a desert, larger rocks slowly move downwards as smaller sand is blown away.
Next, give students a piece of cloth.
Show them how to fold the cloth to make layers, adding a thin layer of sand between each layer of cloth and also a thin layer of sand on top of the last cloth layer. Then place the rock on top. (See photo.)
Is it harder or easier to blow the sand away from under the rock with the cloth?
Discussion: it should be harder to blow away the sand with the cloth. (If it made no difference students may have had a lot of sand on top of the upper layer of cloth - the rock should be sitting on only a thin layer of sand over the top cloth layer.)
The cloth models plant roots, which hold sand (or soil) in place and slow down erosion by wind (or by water).
Next give students some counters.
Show how to make a layer of counters, then a layer of sand, then counters, then sand.
Use wind to blow away the sand between the counters.
Can you make a pile of counters, just by blowing away the sand?
Discuss: It takes a while, but by blowing away the sand, a pile of counters forms.
This models formation of a 'desert pavement'. In a desert, sand is blown away but larger rocks remain. The rocks gradually fall lower and lower as the sand between them is removed. Eventually a layer of rocks remain on top of a lowered ground, protecting against further erosion. The layer of rocks on top is called a desert pavement. The lowering of the land surface by wind erosion is called 'deflation'.
Free play.
Students use all the materials they have for free play.
Ideas for them:
Make your own structures e.g. a house, and see if you can make it fall using wind, or by blowing sand into it.
Combine materials with your partner or another tray and create together.
Wrap and more information:
Wind is formed by the Sun heating the Earth, which causes warm air to rise, which causes more air to move in from the side, which is wind.
Wind erosion happens when the surface of the ground is dry with few plants e.g deserts.
When sand is blown into rocks it wears them away - called 'abrasion'. Abrasion can make strangely-shaped rocks e.g. the Hoodoos in Alberta. See this link: https://upload.wikimedia.org/wikipedia/commons/9/9e/Close_up_of_the_Hoo…
Sand that is blown away can pile up into dunes. The shape of the dunes formed depends on the amount of sand and the direction of the wind(s). See second image in this link: https://www.nps.gov/subjects/geology/aeolian-landforms.htm or this link: https://www.researchgate.net/figure/Major-dune-types-as-defined-by-McKe…
Sometimes wind blows dust around the Earth! Dust from the Sahara desert in Africa is carried by winds around the Earth to the Americas! Some of the nutrients in the Amazon rainforest are from Sahara rocks (phosphorus). See this NASA link: https://earthobservatory.nasa.gov/images/146871/dust-traverses-the-atla…
