Giant channels discovered beneath Antarctic ice shelf

Oct 06, 2013
The British Antarctic Survey's Twin Otter survey plane & camp, the plane was used to collect data about the size of the sub-ice-shelf channel. Credit: Neil Ross

Scientists have discovered huge ice channels beneath a floating ice shelf in Antarctica. At 250 metres high, the channels are almost as tall as the Eiffel tower and stretch hundreds of kilometres along the ice shelf. The channels are likely to influence the stability of the ice shelf and their discovery will help researchers understand how the ice will respond to changing environmental conditions.

Researchers from the University of Exeter, Newcastle University, the University of Bristol, the University of Edinburgh, the British Antarctic Survey and the University of York, used satellite images and airborne radar measurements to reveal the channels under the shelf. The channels can be seen on the surface of the ice shelf, as well as underneath, because the ice floats at a different height depending on its thickness.

The researchers also predicted the path of flowing under the part of the ice in contact with the land – known as the ice sheet. They discovered that the predicted flow paths lined up with the channels under the ice shelf at the point where the ice starts to float.

The match-up indicates that the water flow beneath the grounded ice sheet is responsible for the formation of the channels beneath the floating ice shelf. When the meltwater flowing under the ice sheet enters the ocean beneath the ice shelf, it causes a plume of ocean water to form, which then melts out the vast channels under the . Previously, it was thought that water flowed in a thin layer beneath the ice sheet, but the evidence from this study suggests it flows in a more focussed manner much like rivers of water. The way in which water flows beneath the ice sheet strongly influences the speed of ice flow, however, the implications for the future of the ice sheet are yet to be determined.

The ice shelf channel is clearly visible on the MODIS Mosaic of Antarctica image map; the predicted flow route of water beneath the grounded ice sheet aligns with the initiation of the ice shelf channel. The dashed line marks the point at which the ice starts to float. Credit: MODIS Mosaic of Antarctica (MOA) Image Map / Anne le Brocq.

Dr Anne Le Brocq from the University of Exeter said: "If we are to understand the behaviour of the ice sheet, and its contribution to changes in sea level, we need to fully understand the role of water at the base of the ice sheet. The information gained from these newly discovered channels will enable us to understand more fully how the system works and, hence, how the ice sheet will behave in the future."

This is a schematic diagram indicating the approximate scale of one of the ice shelf channels, similar in height to the Eiffel Tower, and Tower Bridge in width. Credit: Anne Le Brocq

Channels of this magnitude have been observed before elsewhere, but their formation has been attributed to purely oceanic processes rather than meltwater exiting the grounded ice sheet. Now, with the connection to the meltwater system established, readily obtainable observations from the channels have the potential to shed light on how meltwater flows at the base of an inaccessible kilometre-thick .

Explore further: NASA's HS3 mission covers transition of Hurricane Cristobal

More information: Paper: dx.doi.org/10.1038/ngeo1977

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User comments : 10

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Neinsense99
2.9 / 5 (28) Oct 06, 2013
Wait for the posters trying to claim that because this wasn't known before, whatever science they don't like must be junk.
VENDItardE
1.5 / 5 (25) Oct 06, 2013
not at all true Nonsense....we just think you are junk. This is science.....you know how that works, right? FACTS NOT OPINIONS?
VendicarE
3.3 / 5 (19) Oct 06, 2013
"you know how that works, right? FACTS NOT OPINIONS?" - VendiTard

When you manage to find some applicable facts, feel free to post them. It will be a nice change of pace from your usual fact free, off topic, denialist claptrap.

NikFromNYC
1.9 / 5 (26) Oct 07, 2013
This study is basic science, unlike Marcott's unretracted fake hockey stick celebrated by statistician Mike Mann and Cook's 2013 fake 97% climate consensus celebrated by Obama. Real science like this will now sadly suffer a massive defunding backlash due to the rogue bully tactics and professional PR firm tutored disinformation campaigning of RealScience.org charlatans known as The Hockey Stick Team since along with loud activists who now amount to mere doomsday cult members, they doubled down on dumb instead of retired early when skeptics ratted them out.
VendicarE
3.2 / 5 (16) Oct 07, 2013
NikkieTard just can't get over the fact that Mann's methods were accepted as valid by the National Institute of Science, and have subsequently been reproduced in kind by dozens of other studies that use different methods and different data sets.

Poor Nikkietard. His brain disease keeps him living in a land of self deceit.

"The Hockey Stick Team since along with loud activists who now amount to mere doomsday cult members" - NikkieTard

A fine example of incoherent jabbering caused by significant Mental Illness.
alfie_null
3 / 5 (8) Oct 07, 2013
A fine example of incoherent jabbering caused by significant Mental Illness.

Or caused by something. There he is with his shiny new chemistry PhD and all that knowledge of organic chemistry, stuck in some lab washing out test tubes or whatever during the lonely wee hours of the morning. Just a thought.
VendicarE
3 / 5 (12) Oct 07, 2013
"There he is with his shiny new chemistry PhD" - Alfie_null

That too is entirely self delusion.
QuixoteJ
2.5 / 5 (13) Oct 07, 2013
By VendicarE: [NikfromNYC] just can't get over the fact that Mann's methods were accepted as valid by the National Institute of Science, and have subsequently been reproduced in kind by dozens of other studies that use different methods and different data sets.
Didn't the recently-released official "non-rising" temperatures over the last decade prove that the hockey stick was a satistical artifact that should have been dropped from the original results, and, in fact, now, does not exist in any form whatsoever anymore?

And now I have to say that I think the ice channels were made by martians, so you can feel unquestionably validated when you make fun of me.
TheGhostofOtto1923
2.7 / 5 (7) Oct 07, 2013
Velly intellestink... There is evidence that such channels have been known already well since 80 years then.
http://www.youtub...pPwyyvLw

-So?
John92
5 / 5 (1) Oct 20, 2013
they need to send some probes down there!