Lakes
Besides ridges, hills, and blankets of till, melting glaciers also leave
behind depressions of various sizes that can become lakes. Landscapes
shaped by glaciers are often dotted with small kettle lakes as well as larger
lakes. A kettle lake is a bowl-shaped depression that was formed by a
block of ice from a glacier and then became filled with water.
1
2
As a glacier moves away, it
leaves huge blocks of ice.
Over time, sediment builds up
around the ice.
3
The ice melts, leaving behind bowls that
become kettle lakes. These lakes are
in Wisconsin.
The last ice sheet in North America formed many kettle lakes
in some regions. Kettle lakes are common in Michigan, Wisconsin,
and Minnesota.
Kettle Lake Formation
How do kettle lakes form?
Kettle lakes form when sediment builds up around
blocks of ice left behind by a retreating glacier.
Use what you know about kettle lake formation
to design a model of the process.
PROCEDURE
1
Use the tray, the ice cubes, and the other materials to model how sediment
builds up around ice blocks.
2 Write a description of the process you used to make your model.
SKILL FOCUS
Designing
models
MATERIALS
•
•
•
•
•
•
shallow tray
ice cubes
modeling clay
sand
gravel
water
TIME
30 minutes
WHAT DO YOU THINK?
• Describe how your model worked. What did you do first? What happened next?
• Did your model accurately represent the formation of kettle lakes? Did it
work? Why or why not?
• What were the limitations of your model? Are there
any aspects of kettle lake formation that are not
represented? If so, what are they?
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