None

This demonstration can be used at any time in an earth science class particularly within lessons about glaciers, climate change, and applications of GPS data. It can be used as an introductory demonstration for students to explore how the crust is flexible. The demonstration takes about 5 - 20 minutes of class time.

This demonstration shows how the crust sinks and rebounds to the weight of a glacier, and how this motion can be measured using GPS. It uses flubber as a proxy to both crust and glacier to show their reactions.

Key concepts covered:

• The crust is not always rigid.
• Glaciers can affect the shape of the Earth.
• As a glacier grows, the weight of the glacier depresses the crust downward. As a glacier shrinks, the crust rebounds upward in the area around the glacier.
• We can use GPS to measure how glaciers are changing by measuring elevation changes over time of the land around them.

How To Make Flubber (Acrobat (PDF) 45kB Oct31 21)

A full video of the Science with Flubber: Glacial Isostasy Demonstration can be found on the UNAVCO YouTube channel.

This is intended to stimulate student interest and initial understanding of glaciers or crustal studies to come. There is no formal assessment. Educators can ask questions to stimulate discussion and do formative assessment of learner understanding.

• Glaciers are retreating - How can we measure the full ice loss? (UNAVCO Video Animation) - this could be used as an extension