<jats:title>Abstract</jats:title><jats:p>Measurements of N<jats:sub>2</jats:sub>/O<jats:sub>2</jats:sub> ratios inside individual air bubbles at various depths in the EDML (Antarctic) ice core are presented here. The small bubbles (diameter less than ~200 µm) in deeper ice are significantly enriched in O<jats:sub>2</jats:sub> compared to the larger bubbles. The N<jats:sub>2</jats:sub>/O<jats:sub>2</jats:sub> ratios show a systematic dependence on bubble size which is not the case for bubbles in shallower ice. This is interpreted as an effect of pressure relaxation during storage of the cores.</jats:p>