Ancient air, trapped in ice
The history of Earth’s atmosphere - and ocean - is written in the Antarctic ice.
The layers of eternal ice trapped in the southern polar ice cap form an archive of the atmosphere, in which not only dust particles and solids but also air and other gases are trapped. In these bubbles – accessed by drilling deep core samples from the ice – one can determine the concentration of different gases.
While scientists have long used the concentrations of oxygen and carbon dioxide in such bubbles to aid historical climate research, a recent study has shown that even the levels of noble gases such as argon and krypton may contain tell-tale clues about the temperature of Earth’s oceans at different points in history.