Flow‐induced mixing in the GRIP basal ice deduced from the CO₂ and CH₄ records

This paper documents a larger degree of mixing in ice near the bottom of an ice sheet than described, or suspected, previously. It shows, thanks to favourable circumstances due to CO 2 and CH 4 production underneath the ice, that flow‐induced mixing within the basal ice has taken place at the scale of a few centimeters in the GRIP core. Such a mechanism must be considered when interpreting the ice properties in the bottom part of ice sheets and must be taken into account as a potential process of layer disruption in the low levels of the Central Greenland ice cores.