Greenland’s icy surface covers a vast liquid aquifer underneath, according to a new joint study by researchers from Ohio and Utah. The researchers hope to incorporate this find into current projections for how melting of the land mass’s remaining ice sheets may progress in the face of global warming.
The research team, which drew from the University of Utah and from the Byrd Polar Research Center at Ohio State University, was extracting ice-core samples from a site in southeastern Greenland in April 2011 when it hit liquid water about 33 feet underground. The water was so deep that the team had to call off further drilling and moved camp to another site two miles away. Here, too, they reached a subsurface water table, though at a further depth of 82 feet.
Sensing a pattern, the researchers used radar instruments to conduct a wide sweep of the area and look for more underground water deposits. They found not just more water deposits, but a continuous layer of water extending from this new site to the original one and for some distance beyond.
That this underground water existed at all was significant, but the timing made it even more so: April 2011 precedes the seasonal melting that Greenland’s ice sheet exhibits every year during the summer months. The water had to have stayed liquid through the winter.
The discovery comes as the Obama administration has endorsed “carbon-capture” technology, an idea was that it would fight global warming by sparing the atmosphere from more greenhouse gases. Mr. Obama has made sea rise and rising temperatures a major focus of his administration, urging Congress to take action and implement a solution.
Some researchers attribute this underground water to moulins, deep shafts that melted water can drill into the ice sheet during the summer months. Some moulins are as wide as 30 feet, so they can convey substantial amounts of liquid water to the base of the cap. Other researchers think that firn—snow that had formed and melted in earlier years and percolated down underground—might be the source of the water.
Wherever it comes from, the water is apparently able to stay liquid because the ice above it shelters it from the aboveground wind and frost. And there appears to be a huge volume of it: The Ohio and Utah researchers’ calculations place the volume of water in between 322 billion and 1.3 trillion tons.
Further questions loom as to what influence this water might have on warming-related ice loss. On the one hand, the water’s relative warmth could accelerate melting of the ice above it. On the other, it might also slow the outflowing of melting water into the oceans, and thus put a brake on sea-level rise.
Either way, Greenland’s ice loss not only continues, but has been rising. The land mass lost ice at an average of 229 billion tons a year in 2005 to 2010, up from 121 billion tons a year in 2993 through 2005.