Willis Resilience Expedition of the deposition rate of Tritium, a radioactive isotope of hydrogen, across Antarctica. The relatively short half-life of Tritium means it can be used to date snow and ice up to around 150 years old. The data can then be used to better understand the global water cycle, which is intrinsically linked to changes in climate. This will be the first large-scale study of Tritium in Antarctica since Tritium returned to normal levels following the spike caused by thermonuclear tests in the 1960s. The samples will be sent to GNS Science, a New Zealand Crown Research Institute, for analysis. Once
Isotope geochemistry usually is given as a multiple of the present atmospheric ratio (Ra). Common values for R/Ra: He/He isotope chemistry is being used to date groundwaters, estimate groundwater flow rates, track water pollution, and provide insights into hydrothermal processes, igneous geology and ore genesis. U-series isotopes are unique amongst radiogenic isotopes because, being in the U-series decay chains, they are both radiogenic and radioactive. Because their abundances are normally quoted as activity ratios rather than atomic ratios, they are best considered separately from the other radiogenic isotope systems. Uranium is well mixed in the ocean, and its decay produces Pa and