Sources and characteristics of terrestrial carbon in Holocene-scale sediments of the East Siberian Sea
Kirsi Keskitalo1, Tommaso Tesi1,3,4, Lisa Bröder1,3, August Andersson1,3, Christof Pearce2,3, Martin Sköld5, Igor P. Semiletov6,7,8, Oleg V. Dudarev7,8, and Örjan Gustafsson1,31Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, 10691, Sweden 2Department of Geological Sciences, Stockholm University, Stockholm, 10691, Sweden 3Bolin Centre for Climate Research, Stockholm University, Stockholm, 10691, Sweden 4CNR-National Research Council of Italy, ISMAR-Marine Science Institute, Bologna, 40129, Italy 5Department of Mathematics, Stockholm University, Stockholm, 10691, Sweden 6International Arctic Research Center, University Alaska Fairbanks, Fairbanks, AK 99775, USA 7Pacific Oceanological Institute, Russian Academy of Sciences, Vladivostok, RU 690041, Russia 8Tomsk National Research Polytechnical University, Tomsk, RU 634050, Russia
Received: 17 Feb 2017 – Accepted for review: 19 Feb 2017 – Discussion started: 21 Feb 2017
Abstract. Thawing of permafrost carbon (PF-C) due to climate warming can remobilise considerable amounts of terrestrial carbon from its long term storage to the marine environment. PF-C can be then buried in sediments or remineralised to CO2 with implications for the carbon-climate feedback. Studying historical sediment records during past natural climate changes can help to understand the response of permafrost to current climate warming. In this study two sediment cores collected from the East Siberian Sea were used to study terrestrial organic carbon sources, composition and degradation during the past ~ 9500 cal yrs BP. The CuO-derived lignin and cutin products combined with δ13C suggest that there was a higher input of terrestrial organic carbon to the East Siberian Sea between ~ 9500 and 8200 cal yrs BP than in all later periods. This high input was likely caused by marine transgression and permafrost destabilisation in the early Holocene climatic optimum. Based on source apportionment modelling using dual-carbon isotope (∆14C, δ13C) data, coastal erosion releasing old Pleistocene permafrost carbon was identified as a significant source of organic matter translocated to the East Siberian Sea during the Holocene.
Keskitalo, K., Tesi, T., Bröder, L., Andersson, A., Pearce, C., Sköld, M., Semiletov, I. P., Dudarev, O. V., and Gustafsson, Ö.: Sources and characteristics of terrestrial carbon in Holocene-scale sediments of the East Siberian Sea, Clim. Past Discuss., doi:10.5194/cp-2017-20, in review, 2017.