HOME

TheInfoList



OR:

Yedoma (russian: едома) is an organic-rich (about 2% carbon by mass)
Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
-age
permafrost Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surface ...
with ice content of 50–90% by volume. Yedoma are abundant in the cold regions of eastern Siberia, such as northern
Yakutia Sakha, officially the Republic of Sakha (Yakutia),, is the largest republic of Russia, located in the Russian Far East, along the Arctic Ocean, with a population of roughly 1 million. Sakha comprises half of the area of its governing Far Eas ...
, as well as in
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
and the
Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
.


Characteristics

The landscape of Yedoma areas is of glacier plains and hills with shallow depressions known as alas. Yedoma usually form in
lowland Upland and lowland are conditional descriptions of a plain based on elevation above sea level. In studies of the ecology of freshwater rivers, habitats are classified as upland or lowland. Definitions Upland and lowland are portions of ...
s or stretches of land with rolling hills where ice wedge polygonal networks are present, in stable relief features with accumulation zones of poor drainage, severe cold and arid
continental climate Continental climates often have a significant annual variation in temperature (warm summers and cold winters). They tend to occur in the middle latitudes (40 to 55 north), within large landmasses where prevailing winds blow overland bringing som ...
zones resulting in scanty vegetation cover, intense
periglacial Periglaciation (adjective: "periglacial", also referring to places at the edges of glacial areas) describes geomorphic processes that result from seasonal thawing of snow in areas of permafrost, the runoff from which refreezes in ice wedges and ot ...
weathering processes, as well as the proximity of sediment sources, such as low mountain ranges and foothills. The amount of
carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...
trapped in this type of permafrost is much more prevalent than originally thought and may be about 210 to 500 Gt, that is a multiple of the amount of carbon released into the air each year by the burning of
fossil fuel A fossil fuel is a hydrocarbon-containing material formed naturally in the Earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel. The main fossil fuels are coal, oil, and natural gas. Fossil fuels m ...
s. Thawing yedoma is a significant source of
atmospheric methane Atmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth's atmosphere. Atmospheric methane is rising. The 20-year globa ...
(about 4 Tg of per year). The Yedoma region currently occupies an area of more than one million square kilometers from northeast
Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
to
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
and
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, and in many regions is tens of meters thick. During the
Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eur ...
, when the global sea level was 120 m lower than that of today, similar deposits covered substantial areas of the exposed northeast Eurasian continental shelves. At the end of the last
ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...
, at the
Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...
transition, thawing yedoma and the resulting
thermokarst Thermokarst is a type of terrain characterised by very irregular surfaces of marshy hollows and small hummocks formed as ice-rich permafrost thaws. The land surface type occurs in Arctic areas, and on a smaller scale in mountainous areas such as ...
lakes may have produced 33 to 87% of the high-latitude increase in atmospheric
methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...
concentration.


See also

*
Alas (geography) Alas ( sah, Алаас) is a shallow depression which occurs primarily in Yakutia, which is formed by subsidence of the Arctic permafrost owing to repeated melting and refreezing. An alas first develops as a shallow lake as melt water fills the ...
*
Baydzharakh Baydzharakh (russian: Байджарах; Yakut: ) is a term based in the Yakut language, referring to a roughly cone-shaped natural rock formation. They are usually composed of siltstone, silty peat or loam. Description Baydzharakhs form owing ...


References


Further reading

*Frederick West (1996), ''American Beginnings'' The University of Chicago Press, , p52 *Velichko 1984, p141, Chapter 15, Tomirdiaro: Periglacial Landscapes and loessa Accumulation in the late pleistocene arctic and subarctic *K. M. Walter, S. A. Zimov, J. P. Chanton, D. Verbyla & F. S. Chapin III, "Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming", Nature, 443, 71-75, 2006
Lutz Schirrmeister, IPY, From the beginning of the Pliocene cooling to the modern warming
– Past Permafrost Records in Arctic Siberia PAST PERMAFROST, Original IPY project no: ID 15,2011, APEX - Arctic Palaeoclimate and its EXtremes *Rutter&Velichko (1997) "Quaternary of northern eurasia: Late pleistocene and holocene landscapes, stratigraphy and environments, Nat W. Rutter, editor-in-chief, Guest editors A. A. Velichko et al., Vols 41/42 July/August 1997, *Late Quaternary environments of Soviet Union, A.A. Velichko, engl edition Wright&Narnosky, pp176-177, University of Minnesota Publ, Longman, London 1984, * * * Schirrmeister, L., Fedorov, A. N., Froese, D., Iwahana, G., Van Huissteden, K., Veremeeva, A., eds. (2022). Yedoma Permafrost Landscapes as Past Archives, Present and Future Change Areas. Lausanne: Frontiers Media SA. doi:10.3389/978-2-88976-466-2


External links


Yedoma landscape at the western Laptev Sea coastal plain
{{Siberia-geo-stub Pedology Types of soil Permafrost