Fig. 3: Isotope composition of dissolved Pb in Arctic seawater and Pb isotope composition of potential source regions.
From: The Arctic Ocean is a net sink for anthropogenic lead deposited into the Atlantic Ocean
Three-isotope plot of dissolved Pb (dPb) isotope composition (206Pb/207Pb vs. 208Pb/207Pb) for seawater samples collected in the Arctic Ocean (filled dots), and seawater samples from the North Atlantic Ocean (blue triangles, ref. 15) and Pacific Ocean (green triangles, ref. 101) and snow samples from Greenland as per Sherrell et al. (green dots, ref. 7) and Wensman et al. (yellow dots, ref. 102) (outlined symbols). Fram Strait samples (dark blue dots) are labelled as West Spitsbergen Current Atlantic Water (WSC-AW; one datapoint masked by Canada Basin sample), Recirculating Atlantic Water (RAW), East Greenland Current Polar Surface Water (EGC-PSW) and Arctic Atlantic Water (EGC-AAW), Upper Polar Deep Water (UPDW) and Eurasian Basin Deep Water/Greenland Sea Deep Water (EBDW/GSDW). Arctic Ocean seawater dPb isotope composition is indicated by orange (Amundsen Basin), grey (Makarov Basin), and yellow (Canada Basin) dots. Dissolved Pb isotope composition of the Canadian Arctic Archipelago (CAA) Mc Clure Strait (light blue dots), the CAA Parry Channel (green), and the Bering Strait (black) and Chukchi Shelf (brown) are also indicated. The coloured ellipses in the background represent the Pb isotope composition of potential sources of Pb from countries neighbouring the Arctic Ocean as well as ‘pristine’ marine sediments collected in the Arctic Ocean basins. Canadian (green ellipse), European (blue), Russian (purple) and US (yellow) sources are inferred from aerosol Pb measurements in the respective countries between 1994–199949,103, and 2001–2009104. Chinese aerosol Pb measurements (red ellipse) were from 1994–199949, 2003–2005105, and 2007–2009106. Arctic marine sediment Pb isotope composition (grey ellipse) is from refs. 107,108. Error bars represent two standard deviations (2σ) from replicate measurements. Replicate measurements were not available for Fram Strait samples, and the Canadian Arctic Archipelago (CAA) McClure Strait sample, so error bars in this case represent measurement uncertainty (2σ).
