Something alarming happened during the summer of 2012, a record melt year for the Greenland ice sheet: A massive wave of ice and water moved through one of Greenland's glaciers in a never-before-studied type of ice loss.
According to new research published Friday in the journal Geophysical Research Letters, the giant wave that moved through a single glacier on the Greenland ice sheet was "enormous." Now, researchers are concerned about what effect this new phenomenon could have on rising sea levels.
Lead researcher Surendra Adhikari of the NASA Jet Propulsion Laboratory told Mic he and his team first became aware of the wave when they studied data from the GPS stations placed around the bedrock of the ice sheet.
During the summer of 2012 — already known to be "the most intense melt year" on record — one of those GPS stations recorded a horizontal movement of 15 millimeters between June and September, Adhikari said.
While the distance might not seem like much to the average person, to a scientist like Adhikari it was dramatic and unusual. Usually, a GPS station might record about 1 or 2 millimeters of lateral movement. This was nearly 10 times what was expected.
"We concluded that that kind of big signals can only be generated if we'd had a huge mass loss passing by a nearby glacier," Adhikari said. In other words, whatever had moved the GPS station was so big, it was pushing the bedrock.
"It is definitely alarming," Adhikari added.
The researchers later discovered the record-breaking melt season led to a huge, powerful wave of ice and water passing through a glacier in the Greenland ice sheet in a type of ice loss scientists hadn't seen before. Adhikari and his team used new methods to identify this type of loss, which had previously gone undetected.
Now that we know it's happening, we're likely to see it again, Adhikari said. There is "no doubt" the wave was related to a warming climate, Adhikari said, but it's not yet clear what this type of dramatic ice loss will mean for rising sea levels.
"Probably the biggest question for our generation of scientists is to be able to accurately predict how much the sea level will go up," Adhikari said. "There are so many players, and ice is one of the biggest ones."