Frost weathering

Frost weathering is a collective term for several

Certain frost-susceptible soils expand or heave upon freezing as a result of water migrating via capillary action to grow ice lenses near the freezing front.^[2] This same phenomenon occurs within pore spaces of rocks. The ice accumulations grow larger as they attract liquid water from the surrounding pores. The ice crystal growth weakens the rocks which, in time, break up.^[3] It is caused by the expansion of ice when water freezes, putting considerable stress on the walls of containment. This is actually a very common process in all humid, temperate areas where there is exposed rock, especially porous rocks like sandstone. Sand can often be found just under the faces of exposed sandstone where individual grains have been popped off, one by one. This process is often termed frost spalling. In fact, this is often the most important weathering process for exposed rock in many areas.

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 potholes,^[4] and other forms of pavement roughness.^[5]

Volumetric expansion

The traditional explanation for frost weathering was volumetric expansion of freezing water. When water freezes to

Since research in physical weathering begun around 1900, volumetric expansion was, until the 1980s, held to be the predominant process behind frost weathering.[8] This view was challenged in 1985 and 1986 publications by Walder and Hallet.^[6][8] Nowadays researchers such as Matsuoka and Murton consider the "conditions necessary for frost weathering by volumetric expansion" as unusual.^[6] 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.^{[9][10][11][12][13][14][15]}

See also

• Hydrostatic pressure
  that may also erode in combination with ice blocking outflow routes in mountain regions.
• Ice jacking
• Pore water pressure
• Weathering
• Bratschen
• Solifluction

References