page_title: Frost heaving
hierarchical_section_title: Frost heaving
caption_attribution_description: English: Frost heave undergoing thaw on 21 March 2010 in Norwich, Vermont. The side of the 6-inch (15-cm) heave has the soil removed to reveal (bottom to top) needle ice, which has extruded up from the freezing front through porous soil from a water table below, coalesced ice, which has been subject to freeze-thaw, and thawed soil on top.
context_page_description: Frost heaving is an upwards swelling of soil during freezing conditions caused by an increasing presence of ice as it grows towards the surface, upwards from the depth in the soil where freezing temperatures have penetrated into the soil. Ice growth requires a water supply that delivers water to the freezing front via capillary action in certain soils. The weight of overlying soil restrains vertical growth of the ice and can promote the formation of lens-shaped areas of ice within the soil. Yet the force of one or more growing ice lenses is sufficient to lift a layer of soil, as much as 1 foot or more. The soil through which water passes to feed the formation of ice lenses must be sufficiently porous to allow capillary action, yet not so porous as to break capillary continuity. Such soil is referred to as "frost susceptible". The growth of ice lenses continually consumes the rising water at the freezing front. Differential frost heaving can crack road surfaces—contributing to springtime pothole formation—and damage building foundations. Frost heaves may occur in mechanically refrigerated cold-storage buildings and ice rinks.
context_section_description: Frost heaving (or a frost heave) is an upwards swelling of soil during freezing conditions caused by an increasing presence of ice as it grows towards the surface, upwards from the depth in the soil where freezing  temperatures have penetrated into the soil (the freezing front or freezing boundary). Ice growth requires a water supply that delivers water to the freezing front via capillary action in certain soils. The weight of overlying soil restrains vertical growth of the ice and can promote the formation of lens-shaped areas of ice within the soil. Yet the force of one or more growing ice lenses is sufficient to lift a layer of soil, as much as 1 foot (0.30 metres) or more. The soil through which water passes to feed the formation of ice lenses must be sufficiently porous to allow capillary action, yet not so porous as to break capillary continuity. Such soil is referred to as "frost susceptible".  The growth of ice lenses continually consumes the rising water at the freezing front.  Differential frost heaving can crack road surfaces—contributing to springtime pothole formation—and damage building foundations. Frost heaves may occur in mechanically refrigerated cold-storage buildings and ice rinks.
  Needle ice is essentially frost heaving that occurs at the beginning of the freezing season, before the freezing front has penetrated very far into the soil and there is no soil overburden to lift as a frost heave.
caption: Anatomy of a frost heave during spring thaw. The side of a 6-inch (15-cm) heave with the soil removed to reveal (bottom to top): 
   · Needle ice, which has extruded up from the freezing front through porous soil from a water table below
   · Coalesced ice-rich soil, which has been subject to freeze-thaw
   · Thawed soil on top.
   Photograph taken 21 March 2010 in Norwich, Vermont
exif: {"Image ImageWidth": "4288", "Image ImageLength": "2851", "Image BitsPerSample": "[16, 16, 16]", "Image Compression": "Uncompressed", "Image PhotometricInterpretation": "2", "Image Model": "Canon EOS DIGITAL REBEL XSi", "Image Orientation": "Horizontal (normal)", "Image SamplesPerPixel": "3", "Image XResolution": "300", "Image YResolution": "300", "Image PlanarConfiguration": "1", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS3 Macintosh", "Image DateTime": "2010:03:21 22:21:54", "Image ExifOffset": "296", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "506", "Thumbnail JPEGInterchangeFormatLength": "8539", "EXIF FNumber": "113137/10000", "EXIF DateTimeOriginal": "2010:03:21 09:46:19", "EXIF FocalLength": "21", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "1024", "EXIF ExifImageLength": "681"}