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Photograph taken 21 March 2010 in Norwich, Vermont. 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).
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.
Cultivation, earthworms, frost action and rodents mix the soil and decrease the size of the peds. This structure allows for good porosity and easy movement of air and water. This combination of ease in tillage , good moisture and air handling capabilities, and good structure for planting and germination , are definitive of the phrase good tilth .
Soil bulk density, when determined at standardized moisture conditions, is an estimate of soil compaction. [3] Soil porosity consists of the void part of the soil volume and is occupied by gases or water. Soil consistency is the ability of soil materials to stick together. Soil temperature and colour are self-defining.
The frost line—also known as frost depth or freezing depth—is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of an area, the heat transfer properties of the soil and adjacent materials, and on nearby heat sources.
Soil microbial communities experience shifts in the diversity and composition during dehydration and rehydration cycles. [5] Soil moisture affects carbon cycling a phenomenon known as Birch effect. [6] [7] Temperature variations in soil are influenced by factors such as seasonality, environmental conditions, vegetation, and soil composition.
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Frost weathering is the collective name for those forms of physical weathering that are caused by the formation of ice within rock outcrops. It was long believed that the most important of these is frost wedging, which is the widening of cracks or joints in rocks resulting from the expansion of porewater when it freezes. A growing body of ...