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Characterisation of three regimes of collapsing arctic ice complex deposits on the SE Laptev Sea coast using biomarkers and dual carbon isotopes

Auteur(s) et Affiliation(s)

Dept. of Applied Environmental Science (ITM), Univ., Stockholm, Suede
VONK, J.E.
Dept. of Applied Environmental Science (ITM), Univ., Stockholm, Suede
CHARKIN, A.N.
Pacific Oceanological Inst., Russian Academy of Sciences, Vladivostok, Russie, Federation de
National Research Tomsk Polytechnic Univ., Tomsk, Russie, Federation de
KOSMACH, D.
Pacific Oceanological Inst., Russian Academy of Sciences, Vladivostok, Russie, Federation de
National Research Tomsk Polytechnic Univ., Tomsk, Russie, Federation de
DUDAREV, O.V.
Pacific Oceanological Inst., Russian Academy of Sciences, Vladivostok, Russie, Federation de
National Research Tomsk Polytechnic Univ., Tomsk, Russie, Federation de
SEMILETOV, I.P.
Pacific Oceanological Inst., Russian Academy of Sciences, Vladivostok, Russie, Federation de
International Arctic Research Center (IARC), Univ. of Alaska, Fairbanks, Etats-Unis
National Research Tomsk Polytechnic Univ., Tomsk, Russie, Federation de
GUSTAFSSON, Ö.
Dept. of Applied Environmental Science (ITM), Univ., Stockholm, Suede


Description :
This study identifies signs of organic carbon (OC) degradation in 3 Siberian Ice Complex Deposits (ICD) regimes of coastal erosion through elemental, isotopic and molecular analyses. The degree of erosion appears to determine the extent of degradation. The moisture-limited and beach-protected ICD bluff near Buor-Khaya Cape, characterised by thermokarst mounds (baydzherakhs), represents a dormant regime with limited ongoing degradation. Conversely, the more exposed ICD scarps on eroding riverbanks (Olenek Channel, Lena Delta) and coastal slopes (Muostakh Island) showed more pronounced signs of ongoing OC decay. Different parameters suggest that degradation can partially explain the shift of the OC signature with 14C age in the thawing ICD. Exposure time, degree of erosion, slope gradient and moisture conditions appear to be key factors determining the degradation propensity of OC in exposed ICD. These field results document the lability of OC in ICD upon thaw and illustrate the potential for transferring old OC into the rapidly cycling atmosphere-biosphere carbon pools.


Type de document :
Article de périodique

Source :
Permafrost and periglacial processes, issn : 1045-6740, 2014, vol. 25, n°. 3, p. 172-183, nombre de pages : 12, Références bibliographiques : 2 p.

Date :
2014

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley

Langue :
Anglais
Droits :
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