Under the huge Thwaites Glacier in Antarctica is an unexpected, enormous cavern. It once held 14 billion tons of ice. But, in the course of just three years, it has melted and flowed into the Southern Ocean.

According to a study by NASA, the void was caused by newly discovered ‘fingers’ of warm water flowing into cracks in the glacier caused by mounting climate change. This water then pooled between the ice and rock, eroding away the glacier above.

“As more heat and water get under the glacier, it melts faster,” study lead author and NASA scientist Pietro Milillo said.
And the subsurface ice erosion has disturbing implications.

Not only is more ice melting than previously detected, it shows the 160km wide Thwaites Glacier is not as firmly fixed to the surface of the Antarctic continent as believed.

This means the mass of ice — about the size of Florida — can break up and slip into the sea, much faster than projected.

Worse, Thwaites Glacier acts as a kind of ‘door stop’, preventing adjoining glaciers from sliding towards the sea.

“Understanding the details of how the ocean melts away this glacier is essential to project its impact on sea level rise in the coming decades,” says NASA scientist Eric Rignot.

The void was found by ice-penetrating radar and a series of satellites, all of which are attempting to understand what’s happening to Antarctica as the world warms.

The potential impact is enormous.

Unlike much of the North Pole, an enormous amount of South Pole ice sits on land.

Ice that sits on water does not affect sea levels when it melts.

But new water that flows into the sea does.

And Antarctica is an enormous, ice-covered continent.

Thwaites Glacier alone holds enough ice above sea level to raise sea levels by more than 65cm if it was to melt.

Once gone, surrounding glaciers will have no obstacle in their path, speeding up their melting and the potential release of enough water to raise sea levels by as much as 2.4m.

“We have suspected for years that Thwaites was not tightly attached to the bedrock beneath it,” study author Rignot said in a NASA statement. “Thanks to a new generation of satellites, we can finally see the detail.”

As the loss of these glaciers could result in the inundation of major cities, such as New York, new research teams are set to travel to this, one of the hardest to reach areas on Earth.

The US National Science Foundation and British National Environmental Research Council have initiated a five-year field project, The International Thwaites Glacier Collaboration. It will begin its field observations later this year.