- Frost line
The frost line—also known as "frost depth" or "freezing depth"—is most commonly the depth that the
groundwater insoil is expected to freeze. The frost depth depends on the climatic conditions of an area, theheat transfer properties of the soil and adjacent materials, and on nearby heat sources. For example,snow cover andasphalt insulate the ground and homes can heat the ground (see also "heat island ").Alternatively, in
Arctic andAntarctic locations the freezing depth is so deep that it becomes year-roundpermafrost , and the term "thaw depth " is used instead. Finally, in tropical regions, frost line may refer to the vertical geographicelevation below whichfrost does not occur. [cite web |url=http://www.thefreedictionary.com/frost+line |title=Frost line |format= |work= Dictionary.com |accessdate=2008-06-11]"Frost front" refers to the varying position of the frost line during seasonal periods of freezing and thawing.
Building codes
Building code s sometimes take frost depth into account because offrost heaving which can damage buildings by moving its foundation. Foundations are normally built below the frost depth for this reason.There are many ways to predict frost depth including n-Factors which relate air temperature to soil temperature.
Sample frost lines for various locations
*
Minnesota ,USA (2007):
** Northern counties: convert|5|ft|mcite web |url=http://www.doli.state.mn.us/pdf/bc_map_frost_depth.pdf |title=Frost Depth: Minnesota State Building Code Rules 1303.1600 |format=PDF | publisher = Minnesota Department of Labor and Industry | edition = 2007 | date = 2007-03-09 | accessdate = 2008-06-11] cite web |url=http://www.doli.state.mn.us/pdf/bc_2007msbc.pdf | title = The 2007 Minnesota State Building Code |format=PDF | publisher = Minnesota Department of Labor and Industry | date = 2007-10-09| accessdate = 2008-06-11]
** Southern counties: convert|3.5|ft|mReferences
Wikimedia Foundation. 2010.