Place the window screen or kitchen strainer over the bucket. Pour the sand through the screen to sift it. Save the sand remaining on the screen and discard the sand in the bucket. Divide the saved sand evenly between the two plastic trays.
Smooth the surface of the sand with the ruler. Measure and record the depth of the sand in each tray. Make sure each tray has an equal amount of sand.
Make a medium-sized hole in the sand at one end of both trays. Do not dig all the way to the bottom of the tray. Leave some sand at the bottom of the hole.
Place both trays inside the freezer. Prop up the ends with the hole about 1 inch.
Pour 1/4 cup water into the hole of the first tray. Do not add any water to the second tray.
Leave both trays in the freezer overnight. Add another 1/4 cup water to the first tray each day for two weeks. Do not add any water to the second tray.
After two weeks, measure and record the length of the ice in the first tray.
Remove both trays from the freezer and place them on a flat surface for a few hours. Allow enough time for most of the ice to melt.
Observe and record what each tray looks like. Draw a picture of each tray.
Measure and record sand depth at each end of both trays.

Questions
How long was the ice flow in the first tray?
After the ice melted, how was the sand in the first tray different from the sand in the second tray?
What was the sand depth in the first tray at the beginning of the experiment? What was the sand depth at the end? Answer these questions for the second tray.
Did erosion take place in either tray? Explain your answer.
How do you think the results would change if the trays were propped up two inches?