Walk outdoors after a snow and notice how quiet it seems. Freshly fallen snow works in a manner similar to sound proofing in a recording studio or even carpet inside your home.
The snow absorbs sound waves. As the snow becomes packed down, or more dense, its ability to absorb sound decreases. Even though snow absorbs sound, you may have noticed that sometimes when you walk on snow it squeaks.
WDBJ7 viewer Wanda Graham shared her video of squeaky snow from the recent winter storm.
When you walk on snow, your boots apply a pressure. If the temperature of the snow is warmer than approximately 18°F, then the pressure exerted by your boot partially melts the snow under your boot and no sound is made.
When the snow is colder than 18°F, the pressure from your boot does not melt the snow, and instead the ice crystals beneath your boot are crushed making a squeaking sound.
The fact that the freezing point of water is a function of pressure, also explains why we can ice skate. The pressure exerted by the blade of the ice skate is enough to melt a very thin layer of the ice, allowing the blade to slide over the thin film of water.
Show us your squeak! Upload your squeaky snow video to YouTube and email the link to firstname.lastname@example.org. We may just use it on the air.
Information from this article provided by the Cooperative Institute for Satellite Studies