Radiogenic isotope fingerprint of Wilkes Land–Adélie Coast Bottom Water in the circum‐Antarctic Ocean

Wilkes Land–Adélie Coast Bottom Water encompasses the bottom waters formed around the coast of East Antarctica in the area east of Prydz Bay and west of the Ross Sea (90°E–150°E). Here we show that these bottom waters have not only characteristic physical properties, but also carry a distinct radiogenic isotope signal that traces their dispersal. The Nd, Hf and Pb isotopic compositions of Circum‐Antarctic ferromanganese nodules record the isotopic composition of ambient seawater. Those with the lowest Nd and Hf isotopic ratios and the highest Pb isotopic ratios are from the deep Australian‐Antarctic Basin, and they fingerprint Wilkes Land–Adélie Coast Bottom Water. The data illustrate the potential value of these isotope systems as tracers of present and past deep and bottom waters in the Circum‐Antarctic realm and elsewhere.