14 DAY TRIAL // Scientists with the Ohio State University in the US are now hard at work putting together the highest-resolution map of the Greenland Ice Sheet ever. Thus, they're busy documenting the anatomy of this massive body of ice in unprecedented detail.
Apart from closely studying the ice sheet's surface, which, by the way, spans over an area of roughly 660,230 square miles (about 1,710,000 square kilometers), the researchers are trying to pin down lakes created by meltwater flowing beneath it.
What's interesting is that, while working on this project, the Ohio State University scientists had the chance to witness a massive subglacial lake birthed by meltwater disappear in just a few weeks. Needless to say, the scientists were quite puzzled by the sudden disappearance of this lake.
How a subglacial lake pulled a Houdini
This rather wacky occurrence is detailed in a report published in a recent issue of the journal The Cryosphere. In this paper, the Greenland Ice Sheet explorers explain that this lake that drained in just a few weeks used to hold about 6.7 billion gallons of water.
It sat under the ice at a distance of about 31 miles (50 kilometers) from the southwest Greenland coast, and images of the region taken over the years indicate that, before disappearing, it pooled for well over 4 decades. Apparently, the lake drained all of a sudden in 2011.
Thus, the area that used to accommodate for it is now home to a crater measuring 1.2 miles (some 2 kilometers) across and approximately 230 feet (70 meters) in depth. The body of water is believed to have drained through a tunnel created by meltwater in the ice.
Not the only subglacial lake to play hide and seek
Interestingly enough, the Ohio State University say that this lake was not the only one to vanish within weeks from beneath the Greenland Ice Sheet. On the contrary, they say that, over the past couple of years, one other subglacial lake in this corner of the world emptied not once but twice, and way faster than expected.
This other lake, measuring about 2 miles (3.2 kilometers) in diameter at its widest point, also drained through at least one tunnel in the ice. At one point, the lake lost water at a rate of 57,000 gallons, i.e. about as much as an average backyard swimming pool hold, per second.
Now would be a good time to start worrying
The Greenland Ice Sheet, together with the lakes birthed by meltwater flowing beneath it, has the potential to become a major contributor to rising sea levels. Hence, whatever happens to this massive block of ice concerns us all.
Researchers say that, judging by the behavior of the two lakes whose sudden drainage was documented by the Ohio State University specialists, chances are that the Greenland Ice Sheet is already going through a rough patch and risks losing considerable mass in the years to come.
“The fact that our lake appears to have been stable for at least several decades, and then drained in a matter of weeks – or less – after a few very hot summers, may signal a fundamental change happening in the ice sheet,” scientist Ian Howat said in a statement.
