Ice, pressure, glacier (Score 1)

There is a experiment which shows how heavy objects move through ice but it takes a little bit of time for the demonstration to finish. Equipment: a 5 gallon bucket, a bar of ice, a thin cable and two heavy objects. Put a bar of ice across the 5 gallon bucket, tie or hook two heavy objects to each end of a thin cable then place the cable over the ice. The pressure of the cable on the ice will cause it to melt and the cable will move down through the ice. The ice will reform after the cable has passed. Eventullay a loud thud will be heard as the cable passes completely through the ice and the objects fall to the bottom of the bucket but the bar of ice will still be present across the bucket. Experiment with different weights and ice thicknesses to get the experiment to complete within your required time limit.