A thin section of an ice core collected at Taylor Glacier in Antarctica. The ice core samples contain tiny air bubbles with small quantities of ancient air trapped inside. The researchers use a melting chamber to extract the ancient air from the bubbles and then study its chemical composition. The Rochester research focused on measuring the composition of air from the time of Earth's last deglaciation, 8,000-15,000 years ago. This time period is a partial analog to today.