The vast frozen cap that covers the Arctic Ocean crackles with the energy of a continent-sized slab of ice in constant motion.
As sea ice in the Arctic swells in winter and shrinks in summer, it gets pushed and pulled by winds, dynamic ocean currents and changing temperatures that continually morph its shape and size. But when scientists observe the Arctic on a longer time scale, the floating, frozen landscape in flux reveals a clear trend: The oldest and thickest sea ice in the Arctic is disappearing even faster than younger and thinner ice at the fringe of the polar ice cap. According to a new NASA study, the total area covered by hardened Arctic sea ice that has survived multiple summers is now declining at a rate of 17.2 percent per decade. What was once a sizable circular mass on top of the planet now looks more like a diminishing crescent, clinging to the coastline of Greenland and northern Canada. Watch the visualization below to witness how the Arctic's thickest sea ice has declined from 1980 to 2012.