Physical Weathering: Freezing

Physical Weathering: Freezing Water and Rock Breakage

This video demonstrates how freezing water can cause physical weathering by breaking apart rocks. Two experiments are conducted to observe the expansion of water and its effect on porous rock.

Expanding Water Experiment

• Pour water into two plastic cups.

• Mark the water line on each cup.

• Leave one cup at room temperature and put the other in the freezer overnight.

Effect of Water Expansion in Porous Rock Experiment

• Place a piece of sandstone in each of two plastic cups.

• Label one cup as the freeze cup and the other as the room temperature cup.

• Pour water into both cups.

• Leave one cup at room temperature and put the freeze cup into the freezer overnight.

Observations

• Compare the frozen water with the water that remained at room temperature.

• Note any changes in water level and mark them with a marking pen.

• Observe that ice expands in all directions, sometimes causing the bottom of the cup to puff out.

• Take out the frozen cup with rock and thaw it to examine any changes in appearance or structure of the rock.

• Empty the water from both cups and inspect if there is any difference in breaking apart rocks between those exposed to freezing temperatures and those kept at room temperature.

Conclusion

The expansion of frozen water is a powerful force that can cause physical weathering, leading to rock breakage. This phenomenon explains frost heave, where soil is lifted up by ice crystals.