Science with Flubber: Glacial Isostasy
Using two sets of flubber, one representing the Earth and one representing a glacier, demonstrate how the crust sinks and rebounds to the weight of a glacier, and how this motion can be measured using GPS. Flubber is a rubbery elastic substance, a non-Newtonian elasco-plastic fluid, that flows under gravity, but breaks when under high stress. Flubber is useful for demonstrating a wide range of Earth and glacier processes.
Skills and concepts that students must have mastered
How the activity is situated in the course
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.
Content/concepts goals for this activity
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.
Higher order thinking skills goals for this activity
Other skills goals for this activity
Description and Teaching Materials
How To Make Flubber (Acrobat (PDF) 45kB Oct31 21)
Teaching Notes and Tips
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.
References and Resources
- Glaciers are retreating - How can we measure the full ice loss? (UNAVCO Video Animation) - this could be used as an extension