Ice shelves line the perimeter of Antarctica. This particular ice shelf, called the Nansen ice shelf, measures about 30 miles long and 20 miles wide.
The crack has grown and scientists are worried that the entire structure could break free from the continent and float into Terra Nova Bay in the Southern Ocean.
The Operational Land Imager (OLI) on the Landsat 8 satellite acquired the top image on December 26, 2013. OLI captured the second image on December 16, 2015.
“There’s a huge crack, miles long and sometimes over a hundred yards wide, which runs more or less parallel to the front of the ice shelf,” Ryan Walker, scientists at NASA Goddard wrote in a blog post. “Over the winter, the sea surface freezes and traps small icebergs in the crack, producing a fascinatingly broken ices cape.”
With winter soon to set in, satellite imagery indicated that the cracking ice front was still attached to the shelf. Although, strong winter winds can prevent the water beyond the shelf from freezing. These floating shelves are important for holding back the flow of ice from the interior of the continent to the sea. Ice that sloughs from a floating shelf does not raise sea level. But lose part of the ice shelf, and the seaward flow of land ice can accelerate—a phenomenon that contributes to sea level rise.