question: Why is it called permafrost if it isn't necessarily permanent?
comment: What would you use to describe a situation where the ground if frozen during the whole year? So as long as the climate does not change it will be frozen. & #x200B; A permanent marker pen is not permanent as you can use solvent or scratch it away but we still call them that to distinguish them to pens that is easy to remove like that one used on a whiteboard. & #x200B; Permafrost is there to distinguish it from seasonal frozen ground that freeze in the winter but get warm in the summer. It geology it is ground that is frozen for two or more years.
passages: Section::::Extent.:Continuity of coverage.
   Section::::Extent.:Continuity of coverage.:Discontinuous permafrost.
   "In contrast to the relative dearth of reports on frozen ground in north America prior to World War II, a vast literature on the engineering aspects of permafrost was available in Russian. Beginning in 1942, Siemon William Muller delved into the relevant Russian literature held by the Library of Congress and the U.S. Geological Survey Library so that he was able to furnish the government an engineering field guide and a technical report about permafrost by 1943", year in which he coined the term as a contraction of permamently frozen ground. Although originally classified (as U.S. Army. Office of the Chief of Engineers, "Strategic Engineering Study", no. 62, 1943), in 1947 a revised report was released publicly, which is regarded as the first North American treatise on the subject.
   Section::::Extent.
   In soil science, the sporadic permafrost zone is abbreviated SPZ and the extensive discontinuous permafrost zone DPZ. Exceptions occur in "un-glaciated" Siberia and Alaska where the present depth of permafrost is a relic of climatic conditions during glacial ages where winters were up to colder than those of today.
  
  Section::::Extent.:Continuity of coverage.:Continuous permafrost.
   Permafrost is soil, rock or sediment that is frozen for more than two consecutive years. In areas not overlain by ice, it exists beneath a layer of soil, rock or sediment, which freezes and thaws annually and is called the "active layer". In practice, this means that permafrost occurs at an mean annual temperature of or colder. Active layer thickness varies with the season, but is 0.3 to 4 meters thick (shallow along the Arctic coast; deep in southern Siberia and the Qinghai-Tibetan Plateau). The extent of permafrost varies with the climate: in the Northern Hemisphere today, 24% of the ice-free land area, equivalent to 19 million square kilometers, is more or less influenced by permafrost. Of this area slightly more than half is underlain by continuous permafrost, around 20 percent by discontinuous permafrost, and a little less than 30 percent by sporadic permafrost. Most of this area is found in Siberia, northern Canada, Alaska and Greenland. Beneath the active layer annual temperature swings of permafrost become smaller with depth. The deepest depth of permafrost occurs where geothermal heat maintains a temperature above freezing. Above that bottom limit there may be permafrost, whose temperature doesn't change annually—"isothermal permafrost".
   Section::::Organization and structure.
   Permafrost carbon cycle
  
  The permafrost carbon cycle is a sub-cycle of the larger global carbon cycle. Permafrost is defined as subsurface material that remains below 0 C (32 F) for at least two consecutive years. Because permafrost soils remain frozen for long periods of time, they store large amounts of carbon and other nutrients within their frozen framework during that time. Permafrost represents a large carbon reservoir that is seldom considered when determining global terrestrial carbon reservoirs. Recent and ongoing scientific research however, is changing this view.
   Subsea permafrost occurs beneath the seabed and exists in the continental shelves of the polar regions. These areas formed during the last ice age, when a larger portion of Earth's water was bound up in ice sheets on land and when sea levels were low. As the ice sheets melted to again become seawater, the permafrost became submerged shelves under relatively warm and salty boundary conditions, compared to surface permafrost. Therefore, subsea permafrost exists in conditions that lead to its diminishment. According to Osterkamp, subsea permafrost is a factor in the "design, construction, and operation of coastal facilities, structures founded on the seabed, artificial islands, sub-sea pipelines, and wells drilled for exploration and production." It also contains gas hydrates in places, which are both a "potential abundant source of energy", but also may destabilize, as subsea permafrost warms and thaws, producing large amounts of methane gas, which is a potent green-house gas.
   The permafrost carbon cycle (Arctic Carbon Cycle) deals with the transfer of carbon from permafrost soils to terrestrial vegetation and microbes, to the atmosphere, back to vegetation, and finally back to permafrost soils through burial and sedimentation due to cryogenic processes. Some of this carbon is transferred to the ocean and other portions of the globe through the global carbon cycle. The cycle includes the exchange of carbon dioxide and methane between terrestrial components and the atmosphere, as well as the transfer of carbon between land and water as methane, dissolved organic carbon, dissolved inorganic carbon, particulate inorganic carbon and particulate organic carbon.
   Satellite Snowfield
  
  Satellite Snowfield () is a snowfield at the southeast side of the Walton Mountains situated within the south-central portion of Alexander Island, Antarctica. The snowfield was first mapped by Directorate of Overseas Surveys from satellite imagery supplied by U.S. National Aeronautics and Space Administration in cooperation with U.S. Geological Survey. The name applied by the United Kingdom Antarctic Place-Names Committee (UK-APC) is for the satellites of the planets of the solar system, a theme used in naming several features in this area, mainly glaciers.
   A "serac" is a group or column of ice intersecting crevasses on a glacier.
  
  "Firn" is a type of snow that has been left over from past seasons and has been recrystallized into a substance denser than névé. It is at an intermediate stage between snow and glacial ice.
  
  "Permafrost" is soil at or below the freezing point of water (0°C or 32°F) for two or more years. In practice it is a large stretch of land (found mostly in Siberia) with soil frozen all over deep to the bottom.
   At mean annual soil surface temperatures below the influence of aspect can never be sufficient to thaw permafrost and a zone of "continuous permafrost" (abbreviated to CPZ) forms. A "line of continuous permafrost" in the Northern Hemisphere represents the most southerly border where land is covered by continuous permafrost or glacial ice. The line of continuous permafrost varies around the world northward or southward due to regional climatic changes. In the southern hemisphere, most of the equivalent line would fall within the Southern Ocean if there were land there. Most of the Antarctic continent is overlain by glaciers, under which much of the terrain is subject to basal melting. The exposed land of Antarctica is substantially underlain with permafrost, some of which is subject to warming and thawing along the coastline.
   Permafrost typically forms in any climate where the mean annual air temperature is less than the freezing point of water. Exceptions are found in moist-wintered forest climates, such as in Northern Scandinavia and the North-Eastern part of European Russia west of the Urals, where snow acts as an insulating blanket. Glaciated areas may be exceptions. Since all glaciers are warmed at their base by geothermal heat, temperate glaciers, which are near the pressure-melting point throughout, may have liquid water at the interface with the ground and are therefore free of underlying permafrost. "Fossil" cold anomalies in the Geothermal gradient in areas where deep permafrost developed during the Pleistocene persist down to several hundred metres. This is evident from temperature measurements in boreholes in North America and Europe.
   According to IPCC Fifth Assessment Report there is high confidence that permafrost temperatures have increased in most regions since the early 1980s. Observed warming was up to 3 °C in parts of Northern Alaska (early 1980s to mid-2000s) and up to 2 °C in parts of the Russian European North (1971–2010). In Yukon, the zone of continuous permafrost might have moved poleward since 1899, but accurate records only go back 30 years. It is thought that permafrost thawing could exacerbate global warming by releasing methane and other hydrocarbons, which are powerful greenhouse gases. It also could encourage erosion because permafrost lends stability to barren Arctic slopes.
   Section::::Climate change effects.
  
  Arctic permafrost has been diminishing for many centuries. The consequence is thawing soil, which may be weaker, and release of methane, which contributes to an increased rate of global warming as part of a feedback loop.
  
  Section::::Climate change effects.:Historical changes.
   The term "subatlantic" was first introduced in 1889 by Rutger Sernander to differentiate it from Axel Blytt's "atlantic". It follows upon the previous "subboreal". According to Franz Firbas (1949) and Litt "et al." (2001) it consists of the pollen zones IX and X. This corresponds in the scheme of Fritz Theodor Overbeck to the pollen zones XI and XII.
   Buried surface ice may derive from snow, frozen lake or sea ice, aufeis (stranded river ice) and—probably the most prevalent—buried glacial ice.
  
  Intrasedimental ice forms by in-place freezing of subterranean waters and is dominated by segregational ice which results from the crystallizational differentiation taking place during the freezing of wet sediments, accompanied by water migrating to the freezing front.
  
  Intrasedimental or constitutional ice has been widely observed and studied across Canada and also includes intrusive and injection ice.
   Typically, the below-ground temperature varies less from season to season than the air temperature, with mean annual temperatures tending to increase with depth as a result of the geothermal crustal gradient. Thus, if the mean annual air temperature is only slightly below , permafrost will form only in spots that are sheltered—usually with a northerly aspect—creating "discontinuous permafrost". Usually, permafrost will remain discontinuous in a climate where the mean annual soil surface temperature is between . In the moist-wintered areas mentioned before, there may not be even discontinuous permafrost down to . Discontinuous permafrost is often further divided into "extensive discontinuous permafrost", where permafrost covers between 50 and 90 percent of the landscape and is usually found in areas with mean annual temperatures between , and "sporadic permafrost", where permafrost cover is less than 50 percent of the landscape and typically occurs at mean annual temperatures between .
   Drunken trees are not a completely new phenomenon—dendrochronological evidence can date thermokarst tilting back to at least the 19th century. The southern extent of the subarctic permafrost reached a peak during the Little Ice Age of the 16th and 17th centuries, and has been in decline since then.
  
  Permafrost is typically in disequilibrium with climate, and much of the permafrost that remains is in a relict state. However, the rate of thawing has been increasing, and a great deal of the remaining permafrost is expected to thaw during the 21st century.
   The permafrost carbon cycle (Arctic Carbon Cycle) deals with the transfer of carbon from permafrost soils to terrestrial vegetation and microbes, to the atmosphere, back to vegetation, and finally back to permafrost soils through burial and sedimentation due to cryogenic processes. Some of this carbon is transferred to the ocean and other portions of the globe through the global carbon cycle. The cycle includes the exchange of carbon dioxide and methane between terrestrial components and the atmosphere, as well as the transfer of carbon between land and water as methane, dissolved organic carbon, dissolved inorganic carbon, particulate inorganic carbon and particulate organic carbon.
   Permafrost is defined as ground, soil or rock, including ice or organic material that remains at or below zero degrees Celsius for at least two consecutive years. The regions in which permafrost occurs occupy ~24% (23 million km2) of the Northern Hemisphere. Modelling suggests that permafrost covers have been warming and thawing since the end of the Little Ice Age c. 120 years ago. Access the current global distribution of permafrost here.
   The Arctic region is one of the many natural sources of the greenhouse gas methane. Global warming accelerates its release, due to both release of methane from existing stores, and from methanogenesis in rotting biomass. Large quantities of methane are stored in the Arctic in natural gas deposits, permafrost, and as submarine clathrates. Permafrost and clathrates degrade on warming, thus large releases of methane from these sources may arise as a result of global warming. Other sources of methane include submarine taliks, river transport, ice complex retreat, submarine permafrost and decaying gas hydrate deposits. Preliminary computer analyses suggest that permafrost could produce carbon equal to 15 percent or so of today’s emissions from human activities.
   In the western United States, freezing fog may be referred to as pogonip. It occurs commonly during cold winter spells, usually in deep mountain valleys.
  
  The word pogonip is derived from the Shoshone word "paγi̵nappi̵h", which means "cloud".
  
  In "The Old Farmer's Almanac," in the calendar for December, the phrase "Beware the Pogonip" regularly appears.
  
  In his anthology "Smoke Bellew", Jack London described a pogonip which surrounded the main characters, killing one of them.
   Section::::Loss of permafrost.
  
presuppositions: Permafrost implies frozen ground can not be unfrozen.
corrections: Permafrost does not imply permanent, but permafrost is used to distinguish seasonally frozen ground from ground that is frozen for 2 two or more years. 
raw_presuppositions: Permafrost implies frozen ground can not be unfrozen. Frost that's not necessarily permanent shouldn't be called permanent.
raw_corrections: Permafrost does not imply permanent, but permafrost is used to distinguish seasonally frozen ground from ground that is frozen for 2 two or more years.  Something can be called permanent if, for functional purposes, it's permanent for an extended time.