Air bubble to clathrate hydrate transformation in polar ice sheets: A reconsideration based on the new data from Dome Fuji ice core

[ 1] Mapping the spatial distribution of air bubbles and clathrate hydrates in thick sections of Antarctic ice from Dome Fuji station reveals a considerable redistribution of the inclusions in terms of number and volume in the bubble-to-hydrate transition zone. Analysis of the data indicated that more than 10% of the hydrates nucleated outside the preceding bubbles and more than 30% of the bubbles completely expired due to the gas outflow toward the coexisting hydrates. These features of the gas-hydrate-ice nonequilibrium system are of major importance for modeling the global bubble-to-hydrate transformation in polar ice sheets and thus the results may help improve our ability to extract paleoclimatic information from air inclusions in ice cores.