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 persisted down to the present because their rate of decay is so slow (e.g. uranium-238 and potassium-40). Post-primordial isotopes were created by cosmic ray bombardment as cosmogenic nuclides (e.g., tritium, carbon-14), or by the decay of a radioactive primordial isotope to a radioactive radiogenic nuclide daughter (e.g. uranium to radium). A few isotopes are naturally synthesized as nucleogenic nuclides, by some other natural nuclear reaction, such as when neutrons from natural nuclear fission are absorbed by another atom. As discussed above, only 80 elements have any stable isotopes, and 26 of these have only one stable isotope. Thus, about two-thirds