Scientists Find Lakes Under Antarctica

[vbsurfer3001]

February 16, 2007 — By Associated Press

WASHINGTON -- Beneath the snow, ice and bitter cold of Antarctica, scientists have discovered a network of lakes that fill and empty with rapidly flowing water.

It's a finding that may improve understanding of the interaction between global warming and the melting of Antarctic ice, which could contribute to a worldwide rise in ocean level.

Researchers studying data from satellites were able to measure rises and falls in the overlying ice as the lakes filled and emptied.

More than 100 lakes have been found in West Antarctica, according to research published Thursday in the online issue of the journal Science.

The ice above the lakes is moving as fast as two yards a day -- "really ripping along" in the words of Robert Bindschadler of NASA Goddard Space Flight Center, one of the study's co-authors.

"It's the fast-moving ice that determines how the ice sheet responds to climate change on a short timescale," he said in a statement.

"We aren't yet able to predict what these ice streams are going to do. We're still learning about the controlling processes. Water is critical, because it's essentially the grease on the wheel. But we don't know the details yet," he said.

Lead author Helen Fricker of the University of California San Diego's Scripps Institution of Oceanography said the researchers were surprised by how fast things were moving.

"We thought these changes took place over years and decades, but we are seeing large changes over months," she said.

The researchers studied images from NASA's ICESat, or Ice Cloud and land Elevation Satellite collected from 2003 to 2006. The images gave a much larger view of ice movement.

Previously researchers had to drill deep holes in the ice to determine what was going on underneath, a process that limited then to studying only small areas at a time.

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On the Net:

Science: http://www.sciencemag.org

Source: Associated Press

 

[PacoR]

And.................?
<img src="/forum/images/graemlins/shrug.gif" alt="" />


Big lakes detected under Antarctica
POSTED: 10:49 a.m. EST, February 16, 2007

WASHINGTON (Reuters) -- Lasers beamed from space have detected what researchers have long suspected: big sloshing lakes of water underneath Antarctic ice.
These lakes, some stretching across hundreds of square miles, fill and drain so dramatically that the movement can be seen by a satellite looking at the icy surface of the southern continent, glaciologists reported in Thursday's editions of the journal Science.
Global warming did not create these big pockets of water -- they lie beneath some 2,300 feet of compressed snow and ice, too deep to be affected by temperature changes on the surface -- but knowing how they behave is important to understanding the impact of climate change on the Antarctic ice sheet, study author Helen Fricker said by telephone.
About 90 percent of the world's fresh water is locked in the thick ice cap that covers Antarctica; if it all melts, scientists estimate it could cause a 23-foot rise in world sea levels. Even a 39-inch sea level rise could cause havoc in coastal and low-lying areas around the globe, according to a World Bank study released this week.
"Because climate is changing, we need to be able to predict what's going to happen to the Antarctic ice sheet," said Fricker, of the Scripps Institute of Oceanography and the University of California, San Diego.
"We need computer models to be faithful to the processes that are actually going on on the ice sheet," she said. At this point, computer models do not show how the subglacial water is moving around.
To detect the subglacial lakes, Fricker and her colleagues used data from NASA's ICESat, which sends laser pulses down from space to the Antarctic surface and back, much as sonar uses sound pulses to determine underwater features.
The satellite detected dips in the surface that moved around as the hidden lakes drained and filled beneath the surface glaciers, which are moving rivers of ice.
"The parts that are changing are changing so rapidly that they can't be anything else but (sub-surface) water," she said. "It's such a quick thing."
"Quick" can be a relative term when talking about the movement around glaciers, which tend to move very slowly. But one lake that measured around 19 miles by 6 miles caused a 30 foot change in elevation at the surface when it drained over a period of about 30 months, Fricker said.
The project took observations from 2003 through 2006 of the Whillans and Mercer Ice Streams, two of the fast-moving glaciers that carry ice from the Antarctic interior to the floating ice sheet that covers parts of the Ross Sea.

 

[vbsurfer3001]

If you do a bit more reading on the subject you'd understand that the problem lies with the combination of events. There is a "honeycomb" effect occurring in the ice sheets, increased surface temps are melting surface ice, which bores through the ice sheets to reach either the land mass or one of the above mentioned lakes. This creates a weaker ice sheet and increased viscosity beneath those same ice sheets. With the surface liquid cutting holes through the sheets this increases the likelihood of ice shelves breaking off (as witnessed in the Larsen B shelf 2002). www.nsidc.org/iceshelves/larsenb2002/

It's the combination of thousands even millions, of small changes that add up to global climate change.

 

[speedo]

and at the bottom of the water is more water, ....................this is not my wife!

 

[blakestah]

If you do a bit more reading on the subject you'd understand that the problem lies with the combination of events. There is a "honeycomb" effect occurring in the ice sheets, increased surface temps

The Antarctic continent has not had increases in surface temps...winds are up, though.

are melting surface ice, which bores through the ice sheets to reach either the land mass or one of the above mentioned lakes. This creates a weaker ice sheet and increased viscosity beneath those same ice sheets. With the surface liquid cutting holes through the sheets this increases the likelihood of ice shelves breaking off (as witnessed in the Larsen B shelf 2002). www.nsidc.org/iceshelves/larsenb2002/

It's the combination of thousands even millions, of small changes that add up to global climate change.

It may very well be related to climate change.

But thus far Antarctica is not seeing much warming from global warming. The peninsula is warming, a lot, yes, as is the southern ocean, but not the rest of the continent, and there is no substantial change in ice pack on the rest of the continent. You know, the ice pack that is supposed to be the biggest contributor to ocean level changes.

 

[blakestah]

No, the Antarctic continent is not warming (apart from the peninsula)...and the huge icepack on Antarctica is not diminishing as of yet...and all the science agrees on these facts.

Global warming is real....CO2 is really a contributor...man-made contributions to increased atmospheric CO2 are a near surety...what to do about it is a real conundrum, since India and China are showing no signs of slowing production of CO2.