Searching for the oldest ice in Allan Hills Blue Ice Areas, East Antarctica
Antarctica ice cores reveal a striking coupling between Antarctica temperature and the concentration of atmospheric greenhouse gases (CO2 and CH4) over eight glacial-interglacial cycles. A grand challenge in the ice core research community is to find ice that is older than 800 thousand years. Here we report the evidence of the presence of two-million-year-old ice from cores drilled near Allan Hills Blue Ice Areas, East Antarctica. Despite stratigraphic disturbance to the ice, the gas record remains intact, and could offer, for the first time, direct measurement of pCO2 in the early Pleistocene.