From the University of Cambridge
The subglacial lakes are the first to be identified in Greenland
The study, published in Geophysical Research Letters, discovered two subglacial lakes 800 metres below the Greenland Ice Sheet. The two lakes are each roughly 8-10 km2, and at one point may have been up to three times larger than their current size.
Subglacial lakes are likely to influence the flow of the ice sheet, impacting global sea level change. The discovery of the lakes in Greenland will also help researchers to understand how the ice will respond to changing environmental conditions.
The study, conducted at the Scott Polar Research Institute (SPRI) at the University of Cambridge, used airborne radar measurements to reveal the lakes underneath the ice sheet.
Lead author Dr Steven Palmer, formerly of SPRI and now at the University of Exeter, stated: “Our results show that subglacial lakes exist in Greenland, and that they 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 lakes are unusual compared with those detected beneath Antarctic ice sheets, suggesting that they formed in a different manner. The researchers propose that, unlike in Antarctica where surface temperatures remain below freezing all year round, the newly discovered lakes are most likely fed by melting surface water draining through cracks in the ice. A surface lake situated nearby may also replenish the subglacial lakes during warm summers.
This means that the lakes are part of an open system and are connected to the surface, which is different from Antarctic lakes that are most often isolated ecosystems.
While nearly 400 lakes have been detected beneath the Antarctic ice sheets, these are the first to be identified in Greenland. The apparent absence of lakes in Greenland had previously been explained by the fact that steeper ice surface in Greenland leads to any water below the ice being ‘squeezed out’ to the margin.
The ice in Greenland is also thinner than that in Antarctica, resulting in colder temperatures at the base of the ice sheet. This means that any lakes that may have previously existed would have frozen relatively quickly. The thicker Antarctic ice can act like an insulating blanket, preventing the freezing of water trapped underneath the surface.
As many surface melt-water lakes form each summer around the Greenland ice sheet, the possibility exists that similar subglacial lakes may be found elsewhere in Greenland. 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.
Steven J. Palmer, Julian A. Dowdeswell, Poul Christoffersen, Duncan A. Young, Donald D. Blankenship, Jamin S. Greenbaum, Toby Benham, Jonathan Bamber, Martin J. Siegert. Greenland subglacial lakes detected by radar. Geophysical Research Letters, 2013; DOI: 10.1002/2013GL058383
Abstract
Subglacial lakes are an established and important component of the basal hydrological system of the Antarctic ice sheets, but none have been reported from Greenland. Here, we present airborne radio echo-sounding (RES) measurements that provide the first clear evidence for the existence of subglacial lakes in Greenland. Two lakes, with areas ~8 and ~10 km2, are found in the northwest sector of the ice sheet, ~40 km from the ice margin, and below 757 and 809 m of ice, respectively. The setting of the Greenland lakes differs from those of Antarctic subglacial lakes, being beneath relatively thin and cold ice, pointing to a fundamental difference in their nature and genesis. Possibilities that the lakes consist of either ancient saline water in a closed system or are part of a fresh, modern open hydrological system are discussed, with the latter interpretation considered more likely.
“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.”
And there it is; the requisite money-grubbing anti-science quote. They don’t have a clue what effect if any, these recently-discovered lakes might have, but the hope appears to be that they’ve discovered some sort of positive feedback, or Trenberth’s infamous “arctic death spiral”.
“…are likely…predict… suggesting…most likely…may also… possibility exists… may be… implications…possibilities… interpretation… more likely..”
Leonard Weinstein says:
November 27, 2013 at 7:24 pm
____________
Thanks for the very interesting comment.
In a sane world free from climatism, a discovery like this would simply be allowed to stand alone, without the pasted-on “meaning” of the discovery, and baseless assumptions. Someday.
What interests me is if there is life forms down there, and what manner of life. If there is life, it makes a great case for life under the ice sheets of Europa.
**All these worlds are yours, except Europa. Attempt no landing there.**
Message ends.
Surface soot might help a little or a lot.
http://wattsupwiththat.com/2010/11/03/greenland-ground-zero-for-global-soot-warming/
http://news.discovery.com/earth/global-warming/soot-speeding-greenlands-ice-melt-121207.htm
http://www.theguardian.com/environment/2012/dec/07/greenland-ice-melting-arctic-wildfires
http://e360.yale.edu/slideshow/documenting_earths_disappearing_glaciers/145/1/
So they decided to guess. Is the Greenland ice sheet melt scenarios settled science yet?
I do not have the fainest idea. I gather there are hundreds of hot springs to bath in. See these photos of Erik’s grandkids having a frolic in the warm pools on the fringes of Greenland. Apparently these aprings are not a result of volcanic activity (according to the image page), but by water being “heated by deep layers in the earth’s crust rubbing against each other.”
“The ice in Greenland is also thinner than that in Antarctica, resulting in colder temperatures at the base of the ice sheet. ”
I find this surprising. Antarctica ice thickness is generally >2km thick while Greenland ice thickness is generally >1km. Is there really a difference in insulation between 1km of ice and 2 ?
What’s Up With That?
Why don’t these Calamastrologists just say we discovered a couple of sub-glacial lakes and leave it at that. How do we know these lakes weren’t there in 1900, 1925, 1940 1,000 years ago, 2,000 years ago? Oh, we do know because they say it might have been larger in the past!!! What does this tell me about the future of the ice sheet? What do they know? Is this just a discovery followed by a whole pile of guesswork?
” The thicker Antarctic ice can act like an insulating blanket, preventing the freezing of water trapped underneath the surface.”
Really? All that ice in Greenland isn’t enough “insulation”? These sorts of ad hoc preconceptions have no place in serious science.
Do they have any evidence that the lakes weren’t there before they just discovered them?
Cambridge was once a great university (pre-AGW).
Most importantly ……… are there any fish in those lakes ……. and if so …… how can we get there with our tackle?
Leonard Weinstein says:
November 27, 2013 at 7:24 pm
To add to what Leonard Weinstein says: I find their explanation of the changes observed in the supra-glacial lake in the vicinity of the sub-glacial lake to be unimaginative. They automatically assumed it had drained because of the ‘complex ice terrain at the supra-glacial lake surface’. In my view the complex ice terrain could equally well have been formed by wind blowing the partially frozen surface to the lee end of the lake.
Here is an example:
Sounds like the guesses of a high school kid. Can I play? My guess is that it’s the greater pressure of the larger depth of Antarctic ice, not the greater ‘insulation’.
“The setting of the Greenland lakes differs from those of Antarctic subglacial lakes, being beneath relatively thin and cold ice…” Cold ice? is there any other sort?
Some Antarctic lakes are under ‘thin’ ice as well. Where the ice cover in some Antarctic lakes has been drilled, and water tested, they have been found to have microbial activity. Some have bacterial stromatolites (eg lake Vanda). Most of the microbes live in dark, saline water often with low or zero oxygen and many bacteria provide their energy by sulfate reduction reactions. These are often exothermic (give out heat) and enable the water to maintain temperatures above freezing. There is no need for hot springs. Lake Vostok is a very large lake covered by nearly 4 kilometers of ice. The Russians have recently drilled through this ice and found microbe life.
Recent research in east Antarctica has found what appear to be huge, active river channels beneath thick ice which appear to connect some lakes with the ocean. I suspect the Greenland subglacial lakes will be similar to those near the south pole!
So now Global Warming is drying up the lakes in Greenland!
We’re doomed.
http://abcnews.go.com/m/story?id=21040063
http://m.washingtonpost.com/world/japan-south-korea-military-jets-cross-through-china-air-defense-id-zone/2013/11/28/6285d350-5816-11e3-bdbf-097ab2a3dc2b_story.html
The 21st century superpower, China, sent up planes marking off their new territory. (Not Greenland, yet) My thinkolator imagines Slim Pickens as USAF Major TJ “King” Kong leading a B52, “Now I’ve been to a World’s Fair, a picnic and a rodeo and that’s the stupidest thing I’ve ever heard come over a set of headphones, are you sure you got today’s code?”
Greenland without ice cover;
http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~231252~5508520:The-Floor-of-the-Oceans-
Zoomable.