Problems regarding Antarctica's melting glaciers is seen as a surface problem but it is also happening below the surface. Antarctica's glaciers are being melted by warm ocean water near the continent causing them to let go of the seafloor.

This could contribute to rising sea levels around the world.

Retreating Ice

Underground Antarctica's ice sheet is being melted away by the warmer ocean water. A new study published in the journal Nature Geoscience shows that ice is being detached from the seafloor. The study was done by researchers from the University of Leeds.

Researchers were able to make the first map of the entire Antarctic ice sheet's grounding line, it showed that it is shifting. The study presents data that the Southern Ocean thawed an area of 565 square miles or Greater London between 2010 and 2016. Researchers found that the grounding line was retreating extremely at 8 out of the 65 largest glaciers.

The speed of deglaciation occurred at around 82 feet (25 meters) per year and the glaciers at the grounding line have been retreating at more than five times that rate. A fifth of the ice sheet in West Antarctica melted away faster than the speed of deglaciation. Retreating ground lines can expose more ice to the ocean which would let it flow outward faster.  

Only about 2 percent of the entire Antarctic grounding line retreated at the accelerated rate, and some parts of the continent are not retreating at all. If the rates don't slow down, however, this could lead to part of the inland ice sheet to collapse into the ocean. This much ice falling into the ocean can cause a sea level rise of 10 feet by 2100.

This showed that there are only some parts of Antarctica that are melting while others are remaining the same.

Mapping The Grounding Line

Grounding lines are about half a mile or more below sea level and are not able to be accessed with submersibles. This makes it difficult to be able to map the grounding line for researchers. To map the grounding line, scientists used a combination of satellite imagery and buoyancy equations.

Researchers tracked the retreat of the grounding line by using the European Space Agency's CryoSat-2 to track the 9,942 miles of coastline. Cryosat-2 was made to track the changes in elevation of the ice sheet. To be able to measure the retreat, scientists used measurements of the horizontal motion of the grounding line.

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