Scientists discover “supersaline” lakes in the Arctic that stay liquid at –18 degrees

Published: April 25, 2018

Devon Ice Cap [Credit: Anja Rutishauser]

If you’re like most people, you probably think that water always freezes at zero degrees. After all, it’s one of the first scientific facts most of us learn. But it turns out the facts are often more complicated than we realize, and that the workings of the natural world are infinitely complex, as a recent discovery in the Arctic illustrates.

Scientists unexpectedly found two supersaline lakes in Nunavut, buried beneath glacial ice of the Devon Ice Cap. The lakes, which were 1,800 and 2,500 feet below the surface, and which have likely been there for thousands of years, possess many fascinating properties. For starters, they are liquid, despite existing in temperatures that dip as low –18°C.

Radar imaging of subglacial lakes beneath Devon Ice Cap
The lakes were discovered using radar imaging [Credit: Science Advances Magazine/Anja Rutishauser]
It turns out the lakes’ extremely high salt content (they’re up to four times as salty as sea water) allows them to remain in a liquid state at temperatures far lower than normal.

“At first, when I looked at the radar data that indicated that there is subglacial water, I was very surprised, and a bit puzzled,” Anja Rutishauser, a PhD student at the University of Alberta, told Gizmodo. “Because of the temperatures below the freezing point at the glacier bed, I did not expect to find liquid water. But once we put all the pieces together with the likely salty rocks underlaying the ice, and the hypersaline nature of the water, I was super excited, because I knew that these lakes are very unique!”

These are the first subglacial lakes to have been found in Canada, and Rutishauser hopes to eventually drill down to the water (which has so far only been viewed via radar) and measure its xact salinity.

The lakes don’t just tell us more about the planet we live on — they also might offer some insight into conditions on other planets. Or, more specifically, conditions on the moons of Jupiter and Saturn, which are believed to have similar subglacial bodies of water. If microbes are living in our own Arctic lakes, then it show us how life could also exist on these moons and other planets.

But for now, as Rutishauer told the CBC, scientists are still figuring out how these lakes on Earth formed, and whether there might be more of them.

“We discovered these lakes, we know they’re there, but we actually don’t know much about them.”

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