Subglacial Lakes Found Beneath Greenland's Ice Sheet Will Help With Investigations In Global Sea Level Change
A research team has discovered a pair of subglacial lakes 2,600 feet under the Greenland Ice Sheet. They are the the first ever subglacial lakes to be discovered in Greenland, according to a report published in the journal Geophysical Research Letters.
Like Us on Facebook
The two lakes, both measuring between 4.9 and 6.2 square miles across could have been considerably larger — up to three times the current size — when they were at their largest dimensions, according to researchers. The study was conducted at the Scott Polar Research Institute (SPRI) at the University of Cambridge with the help of airborne radar to identify the subglacial lakes.
Subglacial lakes, such as the ones discovered in Greenland, could have an impact on the flow of ice sheets, and consequently influence the global sea level change, according to study authors. Scientists use new discoveries, such as the one in the current study, to better understand how changing environmental conditions will affect the ice. Several factors determine how sea level rises and falls, including whether ice or water is added to the sea.
Lead author and former SPRI researcher Dr. Steven Palmer, now at the University of Exeter claimed that the subglacial lakes discovered in Greenland "form an important part of the ice sheet's plumbing system because the way in which water moves beneath ice sheets strongly affects ice flow speeds; improved understanding of these lakes will allow us to predict more accurately how the ice sheet will respond to anticipated future warming."
The research team believes that there is a difference in the way the newly discovered lakes, and those found beneath Antarctic ice sheets, were formed. In Antarctica, surface temperatures remain sub-zero throughout the year, while the recently identified subglacial lakes are probably fed by melting surface water draining in through cracks on the ice. In addition, according to Dr. Palmer and colleagues, these subglacial lakes could possibly be replenished - at least partially - during the warm summers, from a nearby surface lake. In other words, these lakes, unlike the frequently isolated Antarctic lakes were part of an open system connected to the surface.
There are currently about 400 known lakes under the Antarctic ice sheets, but these two are the first ones identified in Greenland, according to the research team. In case of Greenland, it was thought that the steeper surface there squeezes water below the ice to the margin. In addition, the thinner ice sheets in Greenland offer no insulation, unlike the thicker Antarctic ice that prevents water below the surface from freezing.
There is a strong possibility that more subglacial lakes could be found in Greenland because many surface melt-water lakes form there each summer, according to the University. "The way in which water flows beneath the ice sheet strongly influences the speed of ice flow, so the existence of other lakes will have implications for the future of the ice sheet."
© 2012 iScience Times All rights reserved. Do not reproduce without permission.