The winter ice
pack in the Arctic
was once dominated
by multi-year*,
thick ice. Today,
very little old
ice remains. This
animation shows
maps of sea i
(more)
The winter ice pack in the Arctic was once dominated by multi-year*, 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. *Revised on 2/21/14. Caption originally said "old." Revised to "multi-year" to reduce ambiguity.
