My research contributes to reconstructing records of past volcanic activity, primarily by identifying volcanic ash and volcanic sulfate deposits in polar ice core records. We combine high resolution sulfur isotope analysis of deposited volcanic aerosols with tephra geochemical analysis to better understand characteristics of past volcanic events including eruptive source, plume height and stratospheric SO₂ injection. Fingerprinting previously unknown eruptions in this way is essential to aid our evaluation of the climate forcing associated with explosive volcanic events, the frequency at which they occur and the hazards posed by volcanic ash plumes.