The patterned ground below Mugi Hill on Mount Kenya is caused by frost heaving. Patterned ground is a term used to describe the distinct and often symmetrical geometric shapes formed by ground material in Periglacial regions Mount Kenya is the highest Mountain in Kenya, and the second highest in Africa (after Mount Kilimanjaro) ^[1]

Frost heaving (or frost heave) occurs when soil expands and contracts due to freezing and thawing. Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel This process can damage plant roots through breaking or desiccation, cause cracks in pavement, and damage the foundations of buildings, even below the frost line. Plants are living Organisms belonging to the kingdom Plantae. ROOT is an object-oriented program and library developed by CERN. Desiccation is the state of extreme dryness or the process of extreme drying A foundation is a Structure that transfers loads to the earth The frost line —also known as frost depth or freezing depth —is most commonly the depth that the Groundwater in Soil is expected Moist, fine-grained soil at certain temperatures is most susceptible to frost heaving. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature

Cause

Originally, frost heaving was thought to occur due simply to the freezing of water in soil. However, the vertical displacement of soil in frost heaving can be significantly greater than the expansion that occurs when ice freezes. In the 1960s, frost heaving was demonstrated in soil saturated in benzene and nitrobenzene, which contract when they freeze. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 Nitrobenzene, also known as nitrobenzol or oil of mirbane, is an Organic compound with the Chemical formula C 6

Frost creep, an effect of frost heave, involves a freeze-thaw action allowing mass movement down slope. Slope is used to describe the steepness incline gradient or grade of a straight line. The soil or sediment is frozen and in the process moved upward perpendicular to the slope. Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of In Geometry, two lines or planes (or a line and a plane are considered perpendicular (or orthogonal) to each other if they form congruent When thaw occurs the sediment moves downwards thus mass movement occurs.

The current understanding is that certain soil particles have a high affinity for liquid water. As the liquid water around them freezes, these soils draw in liquid water from the unfrozen soils around them. If the air temperature is below freezing but relatively stable, the heat of fusion from the water that freezes can cause the temperature gradient in the soil to remain constant. The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of The soil at the point where freezing is occurring continues to draw in liquid water from the soils below it, which then freezes and builds up into an "ice lens". Depending on the soil's affinity for moisture and amount of moisture available, a significant amount of soil displacement can result.

The earliest known documentation of frost heaving came in the 1600s.

Susceptible soil types

Three conditions are generally necessary for frost heaving to occur:

• freezing temperatures
• a supply of water
• a soil that has:
  • the ability to conduct water
  • a high affinity for water
  • saturation (i. Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel e. the pore spaces are filled with water)

Silty and loamy soil types are susceptible to frost heaving. In terms of Soil texture, soil type usually refers to the different sizes of Mineral particles in a particular sample The affinity of a soil for water is generally related to the surface area of the particles that it is composed of. Clays have a high ratio of surface area to volume and have a high affinity for water. Clay is a naturally occurring material composed primarily of fine-grained Minerals which show plasticity through a variable range of Water content, and Larger particles like sand have a lower ratio of surface area to volume and therefore a low affinity for water. Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles

Conversely, the hydraulic conductivity of a soil is related to the pore size. Soils composed of very small particles like clay have small pores and therefore low hydraulic conductivity. Soils composed of larger particles like sand have larger pores and a higher hydraulic conductivity.

The offsetting nature of these two requirements mean that clayey and sandy soils are less conducive to frost heaving than silt, which has a moderate pore size and moisture affinity. Silt is Soil or rock derived Granular material of a Grain size between sand and clay

Frost creep: Soil locomotion due to frost heave

Frost creep, an effect of frost heave, involves a freeze-thaw action allowing mass movement down slope. Slope is used to describe the steepness incline gradient or grade of a straight line. The soil or sediment is frozen and in the process moved upward perpendicular to the slope. Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of In Geometry, two lines or planes (or a line and a plane are considered perpendicular (or orthogonal) to each other if they form congruent When thaw occurs the sediment moves downwards thus mass movement, or locomotion, occurs.

Structures created by frost heaving

In Arctic regions, frost heaving for hundreds of years can create structures, known as pingos, as high as 60 metres. A pingo, also called a hydrolaccolith is a mound of earth-covered Ice found in the Arctic, subarctic and Antarctica that can reach up to 70 The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International Frost heaving is also responsible for creating stones in unique shapes such as circles, polygons and stripes. A notable example is the remarkably circular stones of the islands of Spitsbergen. Spitsbergen (formerly known as West Spitsbergen, and sometimes misspelled Spitzbergen) is a Norwegian island the largest Island of the

See also

• Frost law

References

External links

• American Concrete Pavement Association Frost Action and Frost Heave
• Canadian Building Digest article
• National Research Council of Canada Simple manhole innovation cuts frost heave in pavement
• American Institute of Physics pictures of frost heaving
• Stone Circles Explained, about stone structures created by frost heaving