Even naysayers are starting to admit to the truth: Climate change is real, and for now, it’s here to stay. But it seems even the darkest clouds come with silver linings. As the coldest parts of our planet begin to thaw, new discoveries are being made – among them, a massive “lake” larger than the entire state of West Virginia, trapped beneath Greenland’s ice.
An Aquifer Lake like No Other
You may know that Greenland’s vast ice sheet is the second largest on the planet, covering about 656,000 square miles or 1,710,000 square kilometers. Its’ melting, along with that of Antarctica’s even larger ice sheet, is a huge factor in scientific projections of rising sea levels in years to come.
This is one reason the discovery of this massive aquifer, which covers approximately 27,000 square miles or 70,000 square kilometers of Greenland’s southeastern region, is of such great interest to scientists. Another reason researchers find the “lake” so fascinating is that it’s composition is different than that of any other known aquifer or body of water. Lora Koenig of the Cryospheric Sciences Laboratory at NASA’s Greenbelt, Maryland Goddard Space Flight Center says it’s best to “think about it like a giant snow cone or slushie, or like a sandbox that is filled with water. There is water in the spaces between the ice crystals.
This liquid water is not like a surface lake, which is a continuous body of water; instead it consists of the minuscule spaces between frozen crystals of ice. This surprised researchers, who have been studying the Greenland Ice sheet for several years; in April of 2011, Rick Forster of the University of Utah led a team of scientists who took core samples prior to the summer melting season began, in an effort to measure upper ice layers, which are mostly made up of compacted snow known as firn.
At the time, the team expected to find only solid snow and ice, as surface temperatures were well below freezing. Instead, they found that the ice they retrieved from just a few meters below the surface was soaked with liquid water and was at exactly freezing. “We were surprised and shocked,” Forster said. “Ice doesn’t melt in this area typically until June, so we knew it was water that had persisted throughout the winter.
Joel Harper, a geoscientist from Missoula’s University of Montana, commented that the discovery of the aquifer beneath the firn “has uncovered a fundamental, but previously overlooked, component of meltwater runoff processes in Greenland.”
Koenig stated that the find was surprising, because “we know ice melts at the surface and water percolates down, but we thought it would refreeze.” She went on to say that the researchers believe fresh snow fell on the ice sheet right after it melted, creating an insulating layer that kept the water at just the right temperature to remain in a liquid state.
In April of 2013, Koenig and a team of her colleagues took additional samples and studied flyover data captured by NASA’s Operation Icebridge radar to calculate the size of the aquifer – ultimately learning of its vast nature. The aquifer layer exists only in the firn layer at depths between 39 and 131 feet beneath the ice’s surface; liquid lakes recently discovered beneath Antarctica’s ice sheet are at depths thousands of meters beneath the ice and atop the bedrock layer.
Scientists are still working to learn how this new discovery correlates to rising sea levels; since meltwater can stay trapped in ice for long periods of time, this may help researchers determine how fast ocean waters will rise in coming years. Now that the “lake” has been discovered, it will be tracked annually, perhaps providing answers to questions about sea level rise and issues surrounding the phenomenon.