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Intro: "Data collected from a NASA ice-watching satellite reveal that the vast ice shelves extending from the shores of western Antarctica are being eaten away from underneath by ocean currents, which have been growing warmer even faster than the air above."

First complete map of the speed and direction of ice flow in Antarctica. (image: NASA/JPL-Caltech/UCI)
First complete map of the speed and direction of ice flow in Antarctica. (image: NASA/JPL-Caltech/UCI)



Antarctic Ice Melting From Below by Warming Ocean

By Jason Major, The Christian Science Monitor

30 April 12

 

 

Antarctica's ice shelves are being melted away by warm ocean currents underneath, shows data collected from a NASA satellite.

ata collected from a NASA ice-watching satellite reveal that the vast ice shelves extending from the shores of western Antarctica are being eaten away from underneath by ocean currents, which have been growing warmer even faster than the air above.

The animation above shows the circulation of ocean currents around the western Antarctic ice shelves. The shelf thickness is indicated by the color; red is thicker (greater than 550 meters), while blue is thinner (less than 200 meters).

Launched in January 2003, NASA's ICESat (Ice, Cloud and land Elevation Satellite) studied the changing mass and thickness of Antarctica's ice from its location in polar orbit. An international research team used over 4.5 million surface height measurements collected by ICESat's GLAS (Geoscience Laser Altimeter System) instrument from Oct. 2005 to 2008. They concluded that 20 of the 54 shelves studied - nearly half - were losing thickness from underneath.

Most of the melting ice shelves are located in west Antarctica, where the flow of inland glaciers to the sea has also been accelerating - an effect that can be compounded by thinning ice shelves which, when grounded to the offshore seabed, serve as dams to hold glaciers back.

Melting of ice by ocean currents can occur even when air temperature remains cold, maintaining a steady process of ice loss - and eventually increased sea level rise.

"We can lose an awful lot of ice to the sea without ever having summers warm enough to make the snow on top of the glaciers melt," said Hamish Pritchard of the British Antarctic Survey in Cambridge and the study's lead author . "The oceans can do all the work from below."

The study also found that Antarctica's winds are shifting in response to climate change.

"This has affected the strength and direction of ocean currents," Pritchard said. "As a result warm water is funnelled beneath the floating ice. These studies and our new results suggest Antarctica's glaciers are responding rapidly to a changing climate."

ICESat completed operations in 2010 and was decommissioned in August of that year. Its successor ICESat-2 is anticipated to launch in 2016.

Read more on NASA’s news release here.

Jason Major is a graphic designer living in Dallas, Texas. He writes about astronomy and space exploration on Universe Today and also on his blog Lights In The Dark, Discovery News and National Geographic News.

 

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+12 # readerz 2012-04-30 08:42
Whether it is an ice shelf, glacier, growing desert in Africa or the Gobi in Asia, loss of thick glaciers in Antarctica or Greenland, the world's fresh water supply is in trouble, and released methane will cause more greenhouse gases. This article is more honest; some satellite pictures of arctic and antarctic sea ice do not show how much of the thick ice has melted underneath, or is a result of a glacier sliding out, such as around Greenland. Expect all kinds of changes in climate; some places on earth could be colder due to air and water currents such as Europe this past winter, others much hotter, all with species at risk of extinction, and billions more people in a giant population explosion. (And Republicans are making birth control harder to come by, and they are profiting off of new summer sea lanes in the arctic).
 
 
+11 # Vern Radul 2012-04-30 08:48
Expect wars as the climate deteriorates.

The report presents the two distorted maps shown below (click the images to view full size) - density equalizing cartograms depicting a comparison of undepleted CO2 emissions by country for 1950-2000 versus the regional distribution of four climate sensitive health consequences (malaria, malnutrition, diarrhea, and inland flood-related fatalities).

The first image shows the world in terms of carbon emissions. America, for instance, is huge. So is China. And Europe. Africa is hardly visible.

The second map shows the world in terms of increased mortality -- that is to say, deaths -- from climate change. Suddenly, America virtually disappears. So does Europe. Africa, however, is grotesquely distended. South Asia inflates.
[snip]
"Loss of healthy life years as a result of global environmental change (including climate change) is predicted to be 500 times greater in poor African populations than in European populations," states the UCL Lancet Commission report bluntly.

http://antemedius.com/content/climate-change-effects-hugely-unequal-globally
 
 
-5 # Cappucino 2012-04-30 09:02
You know, I can really understand the appeal of refusing to admit that global warming exists. Who wants to deal with any of this?!?
 
 
+6 # Vern Radul 2012-04-30 11:50
Do you have children, or grandchildren?

Maybe they'll be more inclined to "deal" with it? If they live through it?
 
 
+6 # Glen 2012-04-30 13:22
I getcha, Cappucino. It isn't easy to "deal with any of this". Therefore: denial. Nevertheless, it is happening and realists must deal and teach their children and grandchildren to deal with it. We must all now be pragmatists and prepare for the future and teach our progeny how to deal with it. Eliminate the emotions and move into preparations.
 
 
+6 # Vern Radul 2012-04-30 09:26
"Ninety five percent of the glaciers in the world are retreating or shrinking... there is no scientific dispute about that"

image sequences from the Extreme Ice Survey, a network of time-lapse cameras recording glaciers receding at an alarming rate, some of the most vivid evidence yet of climate change.

20 minute video:
http://antemedius.com/content/canary-coal-mine-climate-change-time-lapse-photography
 
 
+9 # carolsj 2012-04-30 11:01
It's like watching a train wreck in slow motion. We might be able to put the brakes on if the whole world took decisive action now. Yeah, that's going to happen! All we can do is document our spiral down the drain. I guess it's easier to ignore it and later blame our problems on God and sinners. "Oh, God is punishing us for homosexuality and abortion. That's why we are having these storms and drought."
 
 
-9 # woohooman 2012-04-30 19:29
It's the SUN STUPID!
 
 
-8 # rsb1 2012-05-01 04:05
This article is misleading. There is mention of 'climate change' without explanation. Readers need to understand the effect the polar shift has had on the climate in general and the oceans in particular. The polar shift is more than 16 degrees, which places parts of Antarctica in much warmer water, and as a consequence the underwater ice is melting.
Is this man-made ? NO NO NO NO NO NO
Can we change it ? NO NO NO NO NO NO
What the article does not say is that there are parts of Antarctica that are now colder, and that new ice is forming on the opposite coastline.
 
 
+2 # terrison 2012-05-01 07:28
Quoting rsb1:
This article is misleading. There is mention of 'climate change' without explanation. Readers need to understand the effect the polar shift has had on the climate in general and the oceans in particular...


This "polar shift" theory of yours is a poorly researched conspiracy theory. Discover magazine roundly debunked it (I'm on a phone, I can't copy/paste a link for that, but it was on the first page I googled 'polar shift causing climate change'). The VAST body of evidence, researched over decades, by hundreds of scientists, all over the planet, using the most advanced technology ever seen ( like satellites that continually measure ice thickness over time, from space) all indicates that the factors that are changing the climate, like the levels of co2 in the atmosphere, are man made. They all agree. There are a few outliers who have tried to shunt responsibility for the problem off of humanity's shoulders, but it's just that - irresponsible.
 
 
0 # noitall 2012-05-01 11:25
Continue to believe that if it gives you courage to go on. I want YOU to see your folly.
 
 
+1 # noitall 2012-05-01 11:23
Time is relative. What we are watching is an explosion. Sort of like watching bacon burning. It will happen 'relatively' fast (but excrutiatingly slow by our time). Should have listened to the tin foil-lined 'crazies' 40 years ago. ALAS!
 

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