Historical records of organic matter supply and degradation status in the East Siberian Sea

Lisa Bröder, Tommaso Tesi, August Andersson, Timothy I. Eglinton, Igor P. Semiletov, Oleg V. Dudarev, Per Roos, Örjan Gustafsson

Research output: Chapter in Book / Report / Conference proceedingChapterAcademicpeer-review


Destabilization and degradation of permafrost carbon in the Arctic regions could constitute a positive feedback to climate change. A better understanding of its fate upon discharge to the Arctic shelf is therefore needed. In this study, bulk carbon isotopes as well as terrigenous and marine biomarkers were used to construct two centennial records in the East Siberian Sea. Differences in topsoil and Pleistocene Ice Complex Deposit permafrost concentrations, modeled using δ13C and δ14C, were larger between inner and outer shelf than the changes over time. Similarly, lignin-derived phenol and cutin acid concentrations differed by a factor of ten between the two stations, but did not change significantly over time, consistent with the dual-carbon isotope model. High molecular weight (HMW) n-alkane and n-alkanoic acid concentrations displayed a smaller difference between the two stations (factor of 3-6). By contrast, the fraction for marine OC drastically decreased during burial with a half-life of 19-27 years. Vegetation and degradation proxies suggested supply of highly degraded gymnosperm wood tissues. Lipid Carbon Preference Index (CPI) values indicated more extensively degraded HMW n-alkanes on the outer shelf with no change over time, whereas n-alkanoic acids appeared to be less degraded toward the core top with no large differences between the stations. Taken together, our results show larger across-shelf changes than down-core trends. Further investigation is required to establish whether the observed spatial differences are due to different sources for the two depositional settings or, alternatively, a consequence of hydrodynamic sorting combined with selective degradation during cross-shelf transport.
Original languageEnglish
Title of host publicationOrganic Geochemistry
PublisherElsevier Ltd
Number of pages15
ISBN (Print)0146-6380
Publication statusPublished - 1 Jan 2016

Publication series

NameOrganic Geochemistry


  • 210Pb
  • Arctic
  • East Siberian Arctic Shelf
  • HMW wax lipids
  • Lignin
  • Monte Carlo
  • Δ14C
  • δ13C


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