Differential Burial of Particulate Organic Carbon at the Chukchi Continental Margin,Arctic Ocean since Late-Pleistocene
The burial of particulate organic carbon is a critical factor in assessing the Arctic Ocean's carbon sequestration capacity,but its burial characteristics on orbital timescales remain highly debated. This study further explores the composition,source,and burial rate of organic matter in the Late Pleistocene and its co-evolution with the surrounding ice sheet by analyzing indicators such as total organic carbon,stable isotopes,and biomarkers in Core M04 at the Chukchi continental margin and the surrounding surface sediments. Results show that terrestrial organic carbon is the primary component of organic carbon burial at the Chukchi continental margin,with significant differences observed over glacial-interglacial cycles,with a low burial rate during the interglacial periods (MIS1 and MIS3) and a sharp increase in burial rate during the glacial periods (MIS4 and MIS2). Combined with the geomorphic features and depositional environment,the expansion of the East Siberian ice sheet (ESIS) and the transport of subglacial drainage systems may be the main controlling factors for the secondary transport of shelf organic carbon and its rapid burial at the continental margin. M04's records provide a new perspective to unravel the characteristics of organic carbon burial,further revealing the mechanisms in the high-sedimentation-rate area of the Arctic Ocean,and help to objectively evaluate the role of Arctic Ocean carbon burial in promoting global carbon sequestration. However,further research,especially records from Arctic Canada,is needed to fully describe the coupling relationship between Arctic Ocean carbon burial and climate transition.