Using Melting Ice to Teach Radiometric Dating
- Explore ice melting as an analogue to radiometric decay.
Context for Use
This activity is appropriate for use in an introductory geology course as a means to discuss the issues of radiometric dating and geologic time.
Description and Teaching Materials
- Funnel and Ring Stand
- Medium sized graduated cylinder
- Chopped/Cubed Ice
- Graph Paper for plotting the melting curve
The author's original article has suggestions for a storyline to go along with the activity.
Teaching Notes and Tips
- Large, thin-walled metal funnels are best because of their high thermal conductivity.
- Don't allow too much time between taking the ice out of the freezer and putting it into the apparatus. Some supercooling is desirable.
- Use a large vertical scale on the graphs to produce a steep slope and enable students to easily project the line back to time-zero.
- Start the activity before class begins so that students don't have to deal with the thermal disequilibrium issues at the outset.
- The first couple of data point can be supplied to shorten the activity.
When students have finished plotting their data, they should check their answer for time-zero against the answer provided by the instructor. Student participation is the aim of this exercise.