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To demonstrate how a glacier moves you will need a cookie
sheet, an ice cube, and a towel.
Unfold the towel and place It on a table or the counter next to the
kitchen sink. Tilt the cookie sheet at an angle with one edge on
the towel. Place the ice cube at the top of the cookie sheet and
watch it move "downhill."
Glaciers move Just like the ice cube did, although glaciers will be
much thicker and heavier.
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| To see how glaciers can pick up and carry rocks, try this. You
will need a deep plastic container, a brick or heavy rock, and a freezer
with a wire rack.
Fill your plastic container with water and freeze it into a block of
ice overnight. Remove the block of ice from the container and place
it directly on the wire rack in the freezer. Then put the brick or
heavy rock on top of the ice block. Leave it in the freezer for 24-48
hours. |
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| When you check your block of ice, you will notice that it has moved
around the wire in the rack and is now frozen to the rack. Glaciers
pick up rocks in the same way. What has happened is that the weight
of the brick has caused the bottom part of your ice block to melt, then
it has re-frozen around the rack.
What do you think will happen if you try this with sand and small pebbles?
Use a cookie sheet covered with wax paper. Spread the sand and pebbles
in a thin layer over the wax paper. Then set another block of ice
on top of this with your brick or heavy stone on top of the ice.
Put it in the freezer for 24-48 hours. Did you get the results you
thought you would?
From T-Town Rockhound 8/00
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