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active layer

active layer A seasonally thawed surface layer, between a few centimetres and about 3 m thick, that lies above the permanently frozen ground in a periglacial environment. It may be subject to considerable expansion on freezing because of the water contained, and this is especially the case if silt-sized particles dominate, with important engineering implications. See also Mollisols and permafrost.

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"active layer." A Dictionary of Ecology. . Encyclopedia.com. 21 Aug. 2017 <http://www.encyclopedia.com>.

"active layer." A Dictionary of Ecology. . Encyclopedia.com. (August 21, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/active-layer-0

"active layer." A Dictionary of Ecology. . Retrieved August 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/active-layer-0

active layer

active layer A seasonally thawed surface soil layer, between a few centimetres and about 3 m thick, that lies above the permanently frozen horizon in a periglacial environment. It may be subject to considerable expansion on freezing, especially if silt-sized particles dominate, and during the melt it may become very mobile. See also MOLLISOLS.

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"active layer." A Dictionary of Plant Sciences. . Encyclopedia.com. 21 Aug. 2017 <http://www.encyclopedia.com>.

"active layer." A Dictionary of Plant Sciences. . Encyclopedia.com. (August 21, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/active-layer-1

"active layer." A Dictionary of Plant Sciences. . Retrieved August 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/active-layer-1

active layer

active layer Seasonally thawed surface layer between a few centimetres and about 3 m thick, lying above the permanently frozen ground in a periglacial environment. It may be subject to considerable expansion on freezing, especially if silt-sized particles dominate, with important engineering implications. See also MOLLISOLS; and PERMAFROST.

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"active layer." A Dictionary of Earth Sciences. . Encyclopedia.com. 21 Aug. 2017 <http://www.encyclopedia.com>.

"active layer." A Dictionary of Earth Sciences. . Encyclopedia.com. (August 21, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/active-layer

"active layer." A Dictionary of Earth Sciences. . Retrieved August 21, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/active-layer