Formation processes of a pocket consisting of bubble-free ice in Hamna ice cliff, Soya Coast, East Antarctica

To clarify the basal hydrology of Soya drainage, East Antarctica, we studied the formation processes of a pocket consisting of bubble-free ice in Hamna ice cliff, Soya Coast by using stable isotope ratios (δ^O andδD). The stable isotopes of this bubble-free ice are almost the same values withoutδ-value fluctuations as those from Rayleigh-type fractionation; isotopically, the bubble-free ice was heavier by 3.8 and 27‰ for δ^O and δD, respectively, than the neighboring bubbly ice. These results suggest that the pocket was formed by meltwater refreezing during the discharge of water to the lower reach under the Soya drainage. Meltwater under the Soya drainage is considered to have flowed through R-channels