This article may be expanded with text translated from the corresponding article in the Finnish Wikipedia. (March 2012)
Click [show] on the right to read important instructions before translating.
View a machine-translated version of the Finnish article.
Google's machine translation is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia.
Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article.
Yedoma is an organic-rich (about 2% carbon by mass) Pleistocene-age loesspermafrost with ice content of 50–90% by volume. The amount of carbon trapped in this type of permafrost is much more prevalent than originally thought and may be about 500 Gt, that is almost 100 times the amount of carbon released into the air each year by the burning of fossil fuels. Thawing yedoma is a significant source of atmospheric methane (about 4 Tg of CH
4 per year).
Yedoma currently occupies an area of more than one million square kilometers in northeast Siberia, and in many regions is tens of meters thick. During the Last Glacial Maximum, 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 last ice age, at the Pleistocene — Holocene transition, thawing yedoma and the resulting thermokarst lakes may have produced 33 to 87% of the high-latitude increase in atmospheric methane concentration.
^Walter KM, Zimov SA, Chanton JP, Verbyla D, Chapin FS (September 2006). "Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming". Nature443 (7107): 71–5. doi:10.1038/nature05040. PMID16957728.
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, ISSN 1040-6182
Late Quaternary environments of Soviet Union, A.A. Velichko, engl edition Wright&Narnosky, pp176-177, University of Minnesota Publ, Longman, London 1984, ISBN 0-582-30125-4
Climate change and Arctic ecosystems: 2. Modeling, paleodata-model comparisons, and future projections, J. O. Kaplan, N. H. Bigelow et al, JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. D19, 8171, doi:10.1029/2002JD002559, 2003
K. M. Walter, M. E. Edwards, G. Grosse, S. A. Zimov, F. S. Chapin III "Thermokarst Lakes as a Source of Atmospheric CH4 During the Last Deglaciation" Science, 318, 633-636, 2007