Carbonaceous material export from Siberian permafrost tracked across the Arctic Shelf using Raman spectroscopy

摘要: Abstract. Warming-induced erosion of permafrost from Eastern Siberia mobilises large amounts organic carbon and delivers it to the East Siberian Arctic Shelf (ESAS). In this study Raman spectroscopy carbonaceous material (CM) was used to characterise, identify track most recalcitrant fraction the organic load: 1463 spectra were obtained surface sediments collected across the ESAS automatically analysed for their peaks. Spectra were classified by peak areas widths into disordered, intermediate, mildly graphitised highly groups distribution these classes was investigated across shelf. Disordered CM prevalent in a permafrost core Kurungnakh Island known have high rates of coastal erosion. Sediments outflows Indigirka Kolyma rivers were generally enriched intermediate CM. These different sediment sources identified distinguished along an E–W transect using Raman spectra, showing that is not homogenised on ESAS. Distal samples, from slope, contained greater amounts compared to rest shelf, attributable degradation or, more likely, winnowing processes offshore. The presence all four spectral classes distal sediments demonstrates degrades much slowly than lipid biomarkers and other traditional tracers terrestrial matter shows that alongside labile component there also conservative transport shelf toward deep ocean. Thus, carbon cycle calculations must consider nature as well amount of carbon liberated thawing other erosional settings.