Krypton gas may be used to date million-year-old polar ice
DOI: 10.1063/PT.5.027864
Los Angeles Times : A new method for dating polar ice analyzes the composition of krypton gas trapped in ancient air bubbles. Called Atom Trap Trace Analysis, the process, which is very similar to radiocarbon dating , measures the ratio of radioactive and stable isotopes of krypton. The importance of the technique is that it may extend the range of dating polar ice from the current limit of 800 000 years to 1.5 million years. That will help date meteorites trapped in older layers of ice and may provide more clues to Earth’s ancient climate. However, the amount of krypton present in the air bubbles is very small, so a large amount of ice has to be melted to obtain enough gas to measure. The researchers are working to refine their method to require smaller amounts of ice.
