You might think the frostiest water on Earth would be lurking beneath a glacier, especially when that glacier happens to be a Florida-sized ice cube in the heart of Antarctica.

Although the Thwaites Glacier is no place to dip your toes, an automated robot called Icefin did manage to do some swimming there — and report back about the surprisingly high temperatures it found there.

The submersible — operated by a team of scientists, including the Georgia Tech team that engineered it — found the region where the glacier and sea meet to be more than 3.6 degrees Fahrenheit (2 degrees Celsius) above the normal freezing temperature. Not only that, but the glacier is already melting to the point that it's contributing to a rise in sea levels,.

More than a bellwether of climate change, the Thwaites Glacier is so crucial in holding back massive amounts of ice water from reaching the sea, it's often referred to as the "doomsday" glacier.

Essentially, it's like an icy finger in a dam. But it doesn't look like it can hold off that "doomsday" flood for much longer. The researchers say the amount of ice flowing past the melting glacier and adjacent ice sheets has doubled in the last 30 years.

By now, you can probably see where this is going: Climate change. We're soaking in it.

"Warm waters in this part of the world, as remote as they may seem, should serve as a warning to all of us about the potential dire changes to the planet brought about by climate change," team member David Holland of New York University tells the Chicago Tribune.

To reach that conclusion, the team, dubbed MELT, or Melting at Thwaites, camped out on the glacier for two months, enduring temperatures of minus 22 F (minus 30 C).

And they had to do some serious digging. As in, drilling a 2,300-foot-deep hole in the glacier — and sending Icefin on a mission where no submersible vessel has gone before — the space below the glacier where ice and water meet, also known as the grounding zone.

From there, Icefin did its job swimmingly, providing the team with the first-ever images of the glacier's foundation on the ocean floor.

You can watch the mesmerizing footage it gathered in the video below:

"We designed Icefin to be able to finally enable access to grounding zones of glaciers, places where observations have been nearly impossible, but where rapid change is taking place," Britney Schmidt, a professor at Georgia Tech and lead scientist for Icefin, notes in a news release. "We're proud of Icefin, since it represents a new way of looking at glaciers and ice shelves.

"For really the first time, we can drive miles under the ice to measure and map processes we can't otherwise reach. We've taken the first close-up look at a grounding zone. It's our 'walking on the moon' moment."

Icefim meticulously measured and imaged those dark depths, giving the researchers enough data to map the area — and raise ever more alarm bells over the growing climate crisis.

"We know that warmer ocean waters are eroding many of West Antarctica's glaciers, but we're particularly concerned about Thwaites," MELT team member Keith Nicholls, who is also an oceanographer with the from British Antarctic Survey, explained in the release from Georgia Tech. "This new data will provide a new perspective of the processes taking place, so we can predict future change with more certainty."

The water beneath the Antarctic's 'doomsday' glacier is uncomfortably warm
The fast-melting Thwaites Glacier won't be able to hold back a massive flood of ice water.