ranged from cheese squeezing, to phase equilibria, to earthquake triangulation. We also gave another go at the classic regelation experiment. I tried this with students in the summer and the ice pieces were too small and some wire was too thin. This time I think we got the right combination.
The idea is that the pressure is great enough just below the wire that it pressure melts the ice but then right above the wire the pressure is low and it refreezes, thereby trapping the wire inside the ice as it makes its way down. Theoretically, the thermal conductivity of the wire is important for the process.
Success!
The students then applied this idea to a long term project in which ice was placed on top of beads and a weight was placed on top. Each week they used a different size or different type of bead. In theory if the bead is embedded into the ice by viscous (solid-state) creep, then it wouldn't matter what type of metal was used. But if it occurs by regelation, then the type of metal (and therefore the thermal conductivity) is important. They had really nice results demonstrating a mix of both types of deformation depending on the conditions (particularly the size of the bead, which controls the stress).
The work was all done in a commercial chest freezer, which isn't ideal for temperature control, since it oscillates with the freezer's duty cycle, but is good for a school project lasting all semester.
They became familiar with running experiments, taking notes, analyzing data and communication results (we had an informal poster session at the end of the term)
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