The European Space Agency’s CryoSat satellite and its Copernicus Sentinel-1 missions have been used to measure subtle changes in the elevation and flow of ice shelves that, in turn, reveal how huge canyons are forming underneath. Warm bottom ocean water is entering the cavity under Antarctica’s Dotson ice shelf and is stirred by Earth’s rotation. This is causing one side of the ice shelf to melt.

The canyon, which has formed over 25 years, is now 200 m deep in places, and the ice just above it is heavily crevassed, affecting the shelf’s future ability to buttress the ice on land. At current thinning rates, the channel could melt through within 40-50 years, making it extremely vulnerable.

Video Credit: ESA/University of Edinburgh–N. Gourmelen/Planetary Visions

Source: American Geophysical Union