The frost line—also known as frost depth or freezing depth—is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of an area, the heat transfer properties of the soil and adjacent materials, and on nearby heat sources. For example, snow cover and asphalt insulate the ground and homes can heat the ground (see also heat island). The line varies by latitude, it is deeper closer to the poles. It ranges in the United States from about zero to six feet. Below that depth the temperature varies, but is always above 32 degrees Fahrenheit(0 degrees Celsius).
Alternatively, in Arctic and Antarctic locations the freezing depth is so deep that it becomes year-round permafrost, and the term "thaw depth" is used instead. Finally, in tropical regions, frost line may refer to the vertical geographic elevation below which frost does not occur.
Frost front refers to the varying position of the frost line during seasonal periods of freezing and thawing.
Read more about Frost Line: Building Codes, Sample Frost Lines For Various Locations
Famous quotes containing the words frost and/or line:
“loosely bound
By countless silken ties of love and thought
To everything on earth the compass round,”
—Robert Frost (1874–1963)
“There’s something like a line of gold thread running through a man’s words when he talks to his daughter, and gradually over the years it gets to be long enough for you pick up in your hands and weave into a cloth that feels like love itself. It’s another thing, though, to hold up that cloth for inspection.”
—John Gregory Brown (20th century)