This manuscript introduces an innovative method for identifying cryptotephra in Antarctic ice cores, which could lead to significant new findings at Mount Brown South (MBS) and throughout Antarctica. The manuscript describes the identification of two new cryptotephra horizons in the MBS ice core from Wilhelm II Land in Antarctica. These cryptotephra originate from the mid-1980s eruptive period of Mt. Erebus and the cataclysmic 1991 eruption of Cerro Hudson. These two tephra horizons are an important addition to the East Antarctic tephrochronological framework. The findings of this study challenge previous assumptions about transport trajectories and pathways and satellite-era ice core chronologies, offering new insights into atmospheric circulation dynamics.