Greenland Ice Sheets Hide Gigantic Unfrozen Lake

Greenland Ice Sheets Hide Gigantic Unfrozen Lake

A gigantic unfrozen lake of meltwater that is roughly 27,000 square miles in size, hidden and trapped beneath the Greenland Ice Sheets, has been discovered by University of Utah researchers. The researchers found it in 2011, as they were in the process of drilling for core samples.

Using ice-penetrating radar, the researchers confirmed the enormous size of the perennial firn aquifer.

Though air temperatures where the researchers attempted to take core samples were hovering at minus four degrees Fahrenheit, when they tried to take two core samples, liquid water poured out of their equipment when the researchers pulled it up. According to a study published on Sunday in Nature Geoscience, the first attempt was at a depth of 33 feet, and in the second, the depth was 82 feet.

Lead author and professor of geography at the University of Utah, Rick Forster, compared the discovery of the lake of water “stored in the air space between the ice particles” to “the juice in a snow cone.”

Forster and his research team have studied the annual rate of snowfall in Greenland and how it varies from year to year since 2010. The area that they’ve been studying covers 14 percent of southeast Greenland, but this relatively small area gets 32 percent of Greenland’s annual snowfall.

What the researchers expected to find in 2011 when they drilled was layers of snow, as they had found in 2010 when they drilled for core samples. When they hit water at the two different depths, though, they concluded that there was a huge aquifer of water trapped there, and it likely remained unfrozen all year long. Forster suggests that the water stays unfrozen because it’s insulated by the “Large amounts of snow” that falls there.

According to Forster, it’s important to know “the aquifer’s capacity to store water from year to year.” That’s because the melting Greenland Ice Sheet is the biggest contributor to the rise of the sea level, so knowing how much meltwater is in the lake “fills a major gap in the overall equation of meltwater runoff and sea levels.”

Global sea levels, according to the National Geographic, have risen dramatically. Over the past century, the rise in the global mean sea level has been from 4 to 8 inches. Earth’s oceans, in the decade of the 1990s alone, rose by .14 inches. That’s a rise of two times faster than the decade of the 1980s.

Melting ice caps and glaciers, ice loss from West Antarctica and Greenland, and thermal expansion are three causes of the rising sea levels Earth is experiencing.

BBC News reported that 34 billion tons of ice per year were lost from the Greenland Ice Sheet between 1992-2001, and between 2002-2011, 215 billion tons of ice were lost per year. The researchers from the University of Utah think that much of the melted ice is being trapped in massive aquifers like the one they discovered. If the water escaped from the layers of ice where it’s been trapped, the global sea level could rise an estimated 6 meters and cause widespread coastal flooding.

The Greenland Ice Sheet covers approximately the same area as the states of Utah, New Mexico, Colorado, Nevada, Arizona and California combined. Previously, calculations about the changes in the mass of the Greenland Ice Sheet hadn’t included the storage of liquid water trapped between sheets of ice.

According to Forster, nobody knows if the lake “might conserve meltwater flow” and, by doing so, “slow down the effects of climate change,” or if it could do the opposite, “providing lubrication to moving glaciers” which could then lead to “calving increasing the mass of ice loss to the global ocean.”

According to Professor Forster, it’s necessary to understand what the role of this immense lake trapped between Greenland’s Ice Sheets is so that we can more accurately “predict sea level rise.” It’s one more factor that has to be taken into consideration to fully understand the factors behind the global rise of sea levels.

Written by: Douglas Cobb


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