Decades ago, the majority of the Arctic’s winter ice pack was made up of thick, perennial ice. Today, very old ice is extremely rare.
This animation tracks the relative amount of ice of different ages from 1987 through early November 2014. Video produced by the Climate.gov team, based on data provided by Mark Tschudi.
As the animation shows, Arctic sea ice doesn’t hold still; it moves continually. East of Greenland, the Fram Strait is an exit ramp for ice out of the Arctic Ocean. Ice loss through the Fram Strait used to be offset by ice growth in the Beaufort Gyre, northeast of Alaska. There, perennial ice could persist for years, drifting around and around the basin’s large, looping current.
Around the start of the 21st century, however, the Beaufort Gyre became less friendly to perennial ice. Warmer waters made it less likely that ice would survive its passage through the southernmost part of the gyre. Starting around 2008, the very oldest ice shrank to a narrow band along the Canadian Arctic Archipelago.
H/T City Lab
