Antarctic water world uncovered
By Jonathan Fildes
Science and technology reporter, BBC News, San Francisco

Giant "blisters" containing water that rapidly expand and contract have been mapped beneath the Antarctic ice sheet.

Fed by a complex network of rivers, the subglacial reservoirs force the overlying ice to rise and fall.

By tracking these changes with Nasa's Ice Cloud and land Elevation Satellite (ICESat) scientists were able to map the extent of the subglacial plumbing.

The results, published in the journal Science, show that some areas fell by up to 9m (30ft) over just two years.

"We didn't realise that the water under these ice streams was moving in such large quantities, and on such short time scales," said Dr Helen Fricker of the Scripps Institution of Oceanography, University of California, and one of the authors of the paper.

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

The results are important for understanding how the Antarctic Ice sheet, which contains nearly 90% of the world's ice, may respond to global warming and how much it may contribute to sea level rise.

Climate response

Nearly 150 subglacial lakes have been mapped beneath the vast Antarctic ice sheet, mostly by glaciologists drilling holes through the ice.

The new ones, detected by satellite, were found under the fast-flowing Whillans and Mercer Ice Streams that carry ice from the interior of the West Antarctic Ice Sheet to the floating Ross Ice Shelf.

Map, BBC
These streams of ice move many metres every day and are of particular interest to climate scientists.

"It's the fast-moving ice that determines how the ice sheet responds to climate change on a short timescale," said Professor Robert Bindschadler of Nasa's Goddard Space Flight Center in Maryland, and one of the researchers on the study.

As atmospheric temperatures rise, melting the ice shelves, their ability to hold back the ice streams on land would be reduced.

"We aren't yet able to predict what these ice streams are going to do."

However, understanding how much water flows beneath the ice is critical because it is one of the factors that determine how fast they flow. More water could speed up the flow of ice into the sea, raising sea levels.

"It's essentially the grease on the wheel," said Professor Bindschadler.

Ebb and flow

Using elevation data from Nasa's ICESat, cross-checked with other Nasa satellites, the team was able to map the rise and fall of the overlying ice, and hence areas where water pooled or flowed away.

Launched in 2003, ICESat can measure changes in elevation as small as 1.5cm (0.6ins) from its orbit 645km (400 miles) above the Earth.

The study revealed a complex network of ponds and rivers, the largest of which occurred under the Whillans ice stream and covered an area of 500 sq km (190 sq miles).

It also showed that water was constantly moving between different reservoirs.

For example, a feature known as Lake Englehardt took just under three years to empty two cubic kilometres (2 trillion litres) of water.

In the same period, Lake Conway filled with an additional 1.2 cubic kilometres (1.2 trillion litres) of water.

Not all of the water was the same as some escaped to the ocean or was refrozen on to the base of the glacier.

Observations like these were only possible using the new satellite technique.

"Until now, we've had just a few glimpses into what's going on down there," said Professor Bindschadler.

"This is the most complete picture to date what's going on beneath fast flowing ice."

The findings were presented at the American Association for the Advancement of Science (AAAS) annual meeting here in San Francisco, US.

Generate your own models of surface sea temps!

http://geochange.er.usgs.gov/data/magsst/magsst.html

See...another Climate Change projection skewed by something they didn't know a few weeks ago !

Constant changes in average mean temperature are historic....as supported by ice core samples.

This clammer to do it now rather than later to save the planet is getting hysterical to the point of most folk switching off.

Al Gore is mostly WRONG and has too much invested to climb down on the hysteria....follow the money !

Always has been change and always will be.....what is the latest view on the below winter temperatures across Europe just now ?

http://arctic-council.org/article/2008/1/coldest_winter_in_many_years

http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20071130/cold_winter_071130/20071130?hub=CTVNewsAt11

http://www.inteldaily.com/?c=148&a=4827

...in the 70's it was Ice Age coming......
http://www.businessandmedia.org/specialreports/2006/fireandice/fireandice.asp

Let's face it...they don't know .


...and another thing...if all the different species are in danger of extinction , how come they are still here after all the previous shifts in temperature?

__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

They didn't taste as good then as they do now because they were cooler...personally, I like my meat warm...

__________________

M. G. Burg
'10 - Dakota SXT - Daily Ride / ≈ 172.5K
.'76 - 450SLC - 107.024.12 / < .89.20 K
..'77 - 280E - 123.033.12 / > 128.20 K
...'67 - El Camino - 283ci / > 207.00 K
....'75 - Yamaha - 650XS / < 21.00 K
.....'87 - G20 Sportvan / > 206.00 K
......'85 - 4WINNS 160 I.O. / 140hp
.......'74 - Honda CT70 / Real 125
.
“I didn’t really say everything I said.”
. . . . . . . . . . . . . . . . . . ~ Yogi Berra ~

You where saying ?

CfA Press Release

Release No.: 03-10
For Release: March 31, 2003

20th Century Climate Not So Hot

Cambridge, MA - A review of more than 200 climate studies led by researchers at the Harvard-Smithsonian Center for Astrophysics has determined that the 20th century is neither the warmest century nor the century with the most extreme weather of the past 1000 years. The review also confirmed that the Medieval Warm Period of 800 to 1300 A.D. and the Little Ice Age of 1300 to 1900 A.D. were worldwide phenomena not limited to the European and North American continents. While 20th century temperatures are much higher than in the Little Ice Age period, many parts of the world show the medieval warmth to be greater than that of the 20th century.

Smithsonian astronomers Willie Soon and Sallie Baliunas, with co-authors Craig Idso and Sherwood Idso (Center for the Study of Carbon Dioxide and Global Change) and David Legates (Center for Climatic Research, University of Delaware), compiled and examined results from more than 240 research papers published by thousands of researchers over the past four decades. Their report, covering a multitude of geophysical and biological climate indicators, provides a detailed look at climate changes that occurred in different regions around the world over the last 1000 years.

"Many true research advances in reconstructing ancient climates have occurred over the past two decades," Soon says, "so we felt it was time to pull together a large sample of recent studies from the last 5-10 years and look for patterns of variability and change. In fact, clear patterns did emerge showing that regions worldwide experienced the highs of the Medieval Warm Period and lows of the Little Ice Age, and that 20th century temperatures are generally cooler than during the medieval warmth."

Soon and his colleagues concluded that the 20th century is neither the warmest century over the last 1000 years, nor is it the most extreme. Their findings about the pattern of historical climate variations will help make computer climate models simulate both natural and man-made changes more accurately, and lead to better climate forecasts especially on local and regional levels. This is especially true in simulations on timescales ranging from several decades to a century.

__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Gore may or may be not completely wrong. I'm not sure if you or most of his critics know enough about the matter to conclude that he's wrong.

I mean, I doubt he's right about all of his claims but I find this utter assurance that there is absolutely nothing to worry about on this matter naive.

Those species that went extinct in previous die-offs are not "here," perhaps some critter similar that was on a similar evolutionary branch survived, such as Woolly Mammoths gone, elephants still here.

Life will go on on the planet, I have little doubt of that. However, the lag time between catastrophe and recovery might be a little longer than most of us can handle.

Or maybe pockets of people will survive here and there, overcoming great hardship, as has happened many times. If you want to believe the people who study these things that is.

ps: Not to be an ass, for your own good and all, it's "clamor."

__________________
1986 300SDL, 362K
1984 300D, 138K

Why believe a buncha pointy-headed pundits?

http://www.ncdc.noaa.gov/paleo/softlib/softlib.html
http://www.ncdc.noaa.gov/paleo/softlib/othersoft.html