Amount of old ice in Arctic, 1987-2013
The winter ice pack in the Arctic was once dominated by old, thick ice.
Today, very little old ice remains.
This animation shows maps of sea ice age from 1987 through the end of October 2013.
Age class 1 means "first-year ice," which is ice that formed in the most recent winter. The oldest ice (9+) is ice that is more than 9 years old.
Animation by NOAA climate.gov, based on research data provided by Mark Tschudi, CCAR, University of Colorado.