AUTHOR=Shin DongYoub , Hahm Doshik , Kim Tae-Wan , Rhee Tae Siek , Lee SangHoon , Park Keyhong , Park Jisoo , Kwon Young Shin , Kim Mi Seon , Lee Tongsup TITLE=Identification of ventilated and submarine glacial meltwaters in the Amundsen Sea, Antarctica, using noble gases JOURNAL=Frontiers in Marine Science VOLUME=9 YEAR=2022 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.951471 DOI=10.3389/fmars.2022.951471 ISSN=2296-7745 ABSTRACT=

To delineate the glacial meltwater distribution, we used five noble gases for optimum multiparameter analysis (OMPA) of the water masses in the Dotson-Getz Trough (DGT), Amundsen Sea. The increased number of tracers allowed us to define potential source waters at the surface, which have not been possible with a small set of tracers. The highest submarine meltwater (SMW) fraction (~0.6%) was present at the depth of ~450 m near the Dotson Ice Shelf. The SMW appeared to travel beyond the continental shelf break along an isopycnal layer. Air-equilibrated freshwater (up to 1.5%), presumably ventilated SMW (VMW) and surface melts, was present in the surface layer (<100 m). The distribution of SMW indicates that upwelled SMW, known as an important carrier of iron to the upper layer, amounts for 29% of the SMW in the DGT. The clear separation of VMW from SMW enabled partitioning of meltwater into locally-produced and upstream fractions and estimation of the basal melting of 53 – 94 Gt yr-1 for the adjacent ice shelves, assuming that the SMW fractions represent accumulation since the previous Winter Water formation. The Meteoric Water (MET) fractions, consisting of SMW and VMW, comprised 24% of those derived from oxygen isotopes, indicating that the annual input from basal melting is far less than the inventory of meteoric water, represented by MET.