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:
“Spring’s an expansive time: yet I don’t trust
March with its peck of dust,
Nor April with its rainbow-crowned brief showers,
Nor even May, whose flowers
One frost may wither thro’ the sunless hours.”
—Christina Georgina Rossetti (1830–1894)
“When all this is over, you know what I’m going to do? I’m gonna get married, gonna have about six kids. I’ll line ‘em up against the wall and tell them what it was like here in Burma. If they don’t cry, I’ll beat the hell out of ‘em.”
—Samuel Fuller, U.S. screenwriter, and Milton Sperling. Samuel Fuller. Barney, Merrill’s Marauders (1962)