frost-active soil

См. также в других словарях:

• Active layer — In environments containing permafrost, the active layer is the top layer of soil that thaws during the summer and freezes again during the autumn. In all climates, whether they contain permafrost or not, the temperature in the lower levels of the …   Wikipedia

• Frost boil — Mud boils near Lapporten, Sweden Frost boils (also known as mud boils, frost scars and mud circles [1]) are upwellings of mud that occur through frost heave and cryoturbation in permafrost areas, such as arctic and alpine regions. They are… …   Wikipedia

• Canadian system of soil classification — The Canadian system of soil classification is more closely related to the American system than any other. They differ in several ways. The Canadian system is designed to cover only Canadian soils. The Canadian system dispenses with a sub order… …   Wikipedia

• North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… …   Universalium

• permafrost — /perr meuh frawst , frost /, n. (in arctic or subarctic regions) perennially frozen subsoil. Also called pergelisol. [1943; PERMA(NENT) + FROST] * * * Perennially frozen earth, with a temperature below 32 °F (0 °C) continuously for two years or… …   Universalium

• arctic — arctically, adv. /ahrk tik/ or, esp. for 7, /ahr tik/, adj. 1. (often cap.) of, pertaining to, or located at or near the North Pole: the arctic region. 2. coming from the North Pole or the arctic region: an arctic wind. 3. characteristic of the… …   Universalium

• agricultural technology — Introduction       application of techniques to control the growth and harvesting of animal and vegetable products. Soil preparation       Mechanical processing of soil so that it is in the proper physical condition for planting is usually… …   Universalium

• climate — /kluy mit/, n. 1. the composite or generally prevailing weather conditions of a region, as temperature, air pressure, humidity, precipitation, sunshine, cloudiness, and winds, throughout the year, averaged over a series of years. 2. a region or… …   Universalium

• Drunken trees — Not to be confused with the floss silk tree, also known as the drunken tree or palo borracho. A drunken forest in Siberia caused by melting permafrost. NASA photo. Drunken trees, tilted trees, or a drunken forest, is a stand of trees displaced… …   Wikipedia

• Life Sciences — ▪ 2009 Introduction Zoology       In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …   Universalium

• United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …   Universalium