Identification of ventilated and submarine glacial meltwaters in the Amundsen Sea, Antarctica, using noble gases

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