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Frost weathering is a collective term for several weathering processes induced by stresses created by the freezing of water into ice. The term serves as an umbrella term for a variety of processes, such as frost shattering, frost wedging, and cryofracturing. The process may act on a wide range of spatial and temporal scales, from minutes to years and from dislodging mineral grains to fracturing . It is most pronounced in high-altitude and high-latitude areas and is especially associated with alpine climate, periglacial, subpolar climate, and , but may occur anywhere at sub-freezing temperatures (between ) if water is present.
Similar processes can act on asphalt pavements, contributing to various forms of cracking and other distresses, which, when combined with traffic and the intrusion of water, accelerate rutting, the formation of ,
Not all volumetric expansion is caused by the pressure of the freezing water; it can be caused by stresses in water that remains unfrozen. When ice growth induces stresses in the pore water that breaks the rock, the result is called hydrofracture. Hydrofracturing is favoured by large interconnected pores or large hydraulic gradients in the rock. If there are small pores, a very quick freezing of water in parts of the rock may expel water, and if the water is expelled faster than it can migrate, pressure may rise, fracturing the rock.
Since research in physical weathering begun around 1900, volumetric expansion was, until the 1980s, held to be the predominant process behind frost weathering. This view was challenged in 1985 and 1986 publications by Walder and Hallet. Nowadays researchers such as Matsuoka and Murton consider the "conditions necessary for frost weathering by volumetric expansion" as unusual. However the bulk of recent literature demonstrates that that ice segregation is capable of providing quantitative models for common phenomena while the traditional, simplistic volumetric expansion does not."Periglacial weathering and headwall erosion in cirque glacier bergschrunds"; Johnny W. Sanders, Kurt M. Cuffey1, Jeffrey R. Moore, Kelly R. MacGregor and Jeffrey L. Kavanaugh; Geology; July 18, 2012, doi: 10.1130/G33330.1
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