Greenland Ice Sheet
Age: 2,625 Years Before Present
A thick section of an ice core from 600 meters below the surface of the Greenland ice sheet reveals air bubbles trapped in the ice, with each air bubble highlighted by side-lighting the ice atop a black background. These air bubbles act as time capsules, revealing the contents of former atmospheric conditions on Earth as far back as 800,000 years. The age of this particular piece of ice is denoted as 2,625 years before present. In this context “present” is standardized around the date of January 1, 1950. Therefore the actual age of the ice is 2,625 years added to the difference between the current year and 1950.