Isotopic constraints on the late Pleistocene glacial water and sediment inputs to the central Arctic ocean

• Published in: Quaternary Science Reviews
• Main Authors: Dong, Linsen, Polyak, Leonid, Zhang, Ying, Portnov, Alexy, Zhang, Hui, Liu, Yanguang, Shi, Xuefa
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier BV 2024
• Subjects: Arctic ocean; Isotope provenance; Sediment stratigraphy; Paleoceanography; Glacial history; Late pleistocene; Arctic Ocean; Ice Sheet; Iceberg*; Lomonosov Ridge
• Online Access: http://hdl.handle.net/10261/364945; https://doi.org/10.1016/j.quascirev.2024.108733

The Quaternary history of the Arctic Ocean reflects pronounced periodic changes in marine and glacial environments. This variability is an important component of the Arctic paleoclimatic system. For more insight, we use isotopic measurements on the detrital (Nd-Sr-Pb) and authigenic (Nd) phases of the Quaternary sediments from the central Arctic Ocean. We analyze core ICE4 from ∼3 km water depth off the Lomonosov Ridge. This core was previously studied for other sedimentary proxies (Dong et al., 2022). The analyzed record is estimated to cover major Late Pleistocene Weichselian/Wisconsinian glaciations occurring over the last ∼100–200 ka. Our results provide new evidence that glacially-derived waters from the glaciated margins reached the bottom of the deep Arctic basins. We infer that these waters were delivered to the deep basins by hyperpycnal flows originating from subglacial outbursts accompanying overflow meltwater and iceberg discharge during glacial/deglacial events. Voluminous outbursts during the older, presumed Early/Middle Weichselian glaciation, ca. 115-35 ka, are traced to the West Siberian margin impacted by the Eurasian Ice Sheet. Similar sedimentary layers are found in longer records from the central Arctic Ocean at older stratigraphic intervals. Sediments constrained to the Last Glacial Maximum have less pronounced glacigenic inputs with a stronger Laurentide Ice Sheet signature. The circulation patterns were likely dependent on the interplay of the timing and extent of the Laurentide and Eurasian ice sheets. We thank the team of the 5th Chinese Arctic Research Expedition for core collection. This study was jointly supported by the National Key Research and Development Program of China (2023YFF0804600), the Basic Scientific Fund for National Public Research Institutes of China (2021Q02), National Natural Science Foundation of China (No.42276256; 42130412), the Taishan Scholar Program of Shandong (Grant No. tspd 20181216), and the Chinese Polar Environment Comprehensive Investigation & ...