New understanding of Antarctic's weight-loss

Oct 22, 2012
New understanding of Antarctic's weight-loss

(Phys.org)—New data which more accurately measures the rate of ice-melt could help us better understand how Antarctica is changing in the light of global warming.

The rate of global is reasonably well-established but understanding the different sources of this rise is more challenging. Using re-calibrated scales that are able to 'weigh' sheets from space to a greater degree of accuracy than ever before, the international team led by Newcastle University, UK, has discovered that Antarctica overall is contributing much less to the substantial sea-level rise than originally thought.

Instead, the large amount of water flowing away from through ice-melt has been partly cancelled out by the volume of water falling onto the continent in the form of snow, suggesting some past studies have overestimated Antarctica's contribution to fast-.

Using Gravity Recovery and (GRACE) , the team calculated ice sheet by more accurately mapping and removing the mass changes caused by the flow of rock beneath Earth's surface.

Publishing their findings today in the academic journal Nature, project lead Professor Matt King said the data meant we were at last close to understanding how Antarctica is changing.

"We have tried to weigh the ice in the past but GRACE only measures the combined effect of the ice changes and the land mass changes occurring beneath the Earth's surface," explains Professor King, Professor of Polar at Newcastle University. "The step forward we have made is to provide a better calculation of the changes so we can correct the to more accurately calculate the changes in ice mass alone.

"Our ice change calculations rely heavily on how well we can account for these important changes taking place beneath the Earth's surface. While the land beneath the ice is moving by no more than a few millimetres-per-year – the thickness of a fingernail –that seemingly small effect significantly alters the rate at which we estimate the ice is changing.

"By producing a new estimate of the land motion we're effectively re-calibrating the scales – in this case the GRACE satellite –so we can more accurately weigh the ice. And what we've found is that present is happening with apparently very little contribution from Antarctica as a whole."

Because most of the Antarctic land surface is covered by ice it has been incredibly difficult to determine where it is rising and falling and by how much. That has meant GRACE data hasn't been able to contribute as much as it could to help scientists understand if Antarctica was growing or shrinking.

"We're now confident it is shrinking," says Professor King, currently on secondment at the University of Tasmania, Australia. "Our new estimate of land motion helps us narrow the range and shifts the best estimate to the lower end of the ice melt spectrum.

"Worryingly, though, the rate of shrinking has sped up in some important locations. The parts of Antarctica that are losing mass most rapidly are seeing accelerated mass loss and this acceleration could continue well into the future."

"The sea level change we're seeing today is happening faster than it has for centuries with just a small contribution from the massive sheet. What is sobering is that sea levels will rise even faster if Antarctica continues to lose increasingly more ice into the oceans."

The research is part of a £600,000 project funded by the Natural Environment Research Council (NERC) to investigate the changing mass of the Antarctic Ice Sheet.

Ice sitting on the Antarctic continent at the peak of the last ice age 20,000 years ago forced the rock beneath to deform and slowly flow away. After that time ice levels generally reduced and the rock within the Earth's mantle more than 100km below the surface has been slowly flowing back in. That change affects the GRACE satellites in exactly the same way as ice moving into and out of the continent.

Since their launch in 2002, the GRACE satellites allow scientists to map Earth's gravity field every 30 days, mapping changes as mass moves around the Earth's surface as well as below it.

Newcastle University's Dr Rory Bingham adds: "There are lots of measurements that tell us something about the recent state of the Antarctic Ice Sheet, but none of those measurements gives the complete picture.

"This research starts to pull that picture together, providing the most accurate GRACE estimate so far of Antarctica's contribution to as a whole, as well as identifying which regions are changing and which are not.

Professor Mike Bentley, of Durham University, UK, who was part of the project team said, "This project brought together a range of scientists including geologists, geodesists and computer modellers to work out the contribution of the Antarctic ice sheets to rise. We have shown that the Antarctic contribution is smaller than some previous estimates, but the is changing very rapidly in some key regions".

Explore further: Coral reveals long-term link between Pacific winds, global climate

More information: "Lower satellite-gravimetry estimates of Antarctic sea-level contribution" M A King, R J Bingham, P Moore, P L Whitehouse, M J Bentley and G A Milne. Nature.

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VendicarD
4 / 5 (4) Oct 23, 2012
What? How can this be possible, after NumenTard spent several days last week swearing that the Antarctic was gaining ice?

I guess he was lying then.

No surprise there.
ValeriaT
2 / 5 (4) Oct 23, 2012
It was NASA, which claimed it. And NASA is well known supporter of AGW. So, does it mean, it's lying now by your own definition?
PinkElephant
4.3 / 5 (6) Oct 23, 2012
ValeriaT,

Are you aware that there is a difference between Antarctic sea ice vs. Antarctic ice sheets? The latter rest on land, and by all indications are shrinking on a yearly comparison basis (slowly, for now...) The former is slowly expanding in winter, then completely melting back each summer...

The article above discusses the landmass ice sheet. The NASA article you linked concerns the sea ice extent.
VendicarD
4.2 / 5 (5) Oct 23, 2012
Your link is about sea ice, not Antarctic ice balance.

"It was NASA, which claimed it." - ValeriaT

KooKooKeeJue.
VendicarD
3.7 / 5 (3) Oct 23, 2012
Time to call some GW denialists.

Here Tardie tardie tardie tardie..
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Here Tardie tardie tardie tardie..
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Here Tardie tardie tardie tardie..
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eachus
2 / 5 (3) Oct 23, 2012
Not to affirm or deny AGW, but I do want to point out a complex interaction here. Antarctica's land level, even where it is below sea level, is rebounding from when Antarctica had more ice. Fine, and it is nice to try to sort out the GRACE data into land and (snow and) ice levels.

But for those worried about global sea level rise, you have to treat the Earth's surface like a balloon filled with water. Rock is pretty much incompressible, so when the land under Antarctica rises, land somewhere else falls. Yes, this can be under the sea bed, but in practice it is normally mostly under mountain ranges. However, the British Isles are tilting for the same reason as Antarctica is rising, and much of North America is rising for the same reason, bounce back from the last ice age.

Net net, this effect results in a slight decrease in sea level. But many of the (low-lying) countries are dropping into the sea, which will make any global (AGW related) sea level increase worse.
ubavontuba
1 / 5 (7) Oct 24, 2012
...suggesting some past studies have overestimated Antarctica's contribution to fast-rising sea levels.
To what "fast-rising" sea level do they refer?

The Global Mean Sea Level has only steadily risen for many decades.

"Worryingly, though, the rate of shrinking has sped up in some important locations. The parts of Antarctica that are losing mass most rapidly are seeing accelerated mass loss and this acceleration could continue well into the future."
If they wish to claim an accelerating Antarctic land ice loss, they're going to have to show a correspondingly accelerating rise in sea levels.

VendicarD
4.2 / 5 (5) Oct 24, 2012
Rapid sea level rise is coincident with the observed warming of the globe.

http://upload.wik...Rise.png

Poor UbVonTard. He just can't get anything right.

"The Global Mean Sea Level has only steadily risen for many decades." - UbVonTard

"If they wish to claim an accelerating Antarctic land ice loss" - UbVonTard

They don't have to show anything to denialists like you.

Your willingness to continually lie disqualifies you from participation in rightful existence.
Caliban
4.2 / 5 (5) Oct 24, 2012


"Worryingly, though, the rate of shrinking has sped up in some important locations. The parts of Antarctica that are losing mass most rapidly are seeing accelerated mass loss and this acceleration could continue well into the future."


If they wish to claim an accelerating Antarctic land ice loss, they're going to have to show a correspondingly accelerating rise in sea levels.


They have to show no such thing --for the very reasons that are set forth in the article, uby. Did you even read it?

Besides --it has only been a couple of weeks past that you were going on and on and on that they hadn't properly accounted for the isostatic rebound of the Antarctic landmass post last ice age, and that therefore there WAS NO accelerating sealevel change/land ice mass balance loss --or some such swill...

Do you have some sort of brain-wasting disease, to cause such a faulty memory?

Or is it that you conveniently forget to remember?

ubavontuba
1 / 5 (6) Oct 25, 2012
The Global Mean Sea Level has only steadily risen for many decades. - Uba
Rapid sea level rise is coincident with the observed warming of the globe.

http://upload.wik...Rise.png
LOL! Vendibot is a blind chatbot. It can't even see that its own graph supports my assertion!

Poor Vendibot. It just can't get anything right.

ubavontuba
1 / 5 (6) Oct 25, 2012
If they wish to claim an accelerating Antarctic land ice loss, they're going to have to show a correspondingly accelerating rise in sea levels. - uba
They have to show no such thing --for the very reasons that are set forth in the article, uby. Did you even read it? - Caliban
Did you? The article is clearly in agreement with what I said.

Besides --it has only been a couple of weeks past that you were going on and on and on that they hadn't properly accounted for the isostatic rebound of the Antarctic landmass post last ice age, and that therefore there WAS NO accelerating sealevel change/land ice mass balance loss --or some such swill...
Right. This article clearly supports what I said then, too. I love vindication.

Do you have some sort of brain-wasting disease, to cause such a faulty memory?
LOL. Perhaps the error lies with you?

VendicarD
3.7 / 5 (3) Oct 25, 2012
In the plot provided, I see no change until 1900 at which point global warming became more pronounced and the oceans began to heat and expand.

http://upload.wik...Rise.png

"LOL! Vendibot is a blind chatbot. It can't even see that its own graph supports my assertion!" - UbVonTard

It is unclear what UnVonTard sees. He seems quite prone to self delusion.
VendicarD
3.7 / 5 (3) Oct 25, 2012
Only in your wildist Tardboy Imagination.

"The article is clearly in agreement with what I said." - UbVonTard

Yup, UbvonTard shows us that in the mind of the insane, black really is the same as white.

"This article clearly supports what I said then, too. I love vindication." - UbVonTard
Caliban
4 / 5 (4) Oct 25, 2012
This article clearly supports what I said then, too. I love vindication.


Do you have some sort of brain-wasting disease, to cause such a faulty memory?

LOL. Perhaps the error lies with you?

It provides only partial support for your claim that ice balance loss was nil --and actually was in a POSITIVE trend, based on poorly quantized isostatic rebound data. This article clearly states that the rebound has been closely confined, but that there is still ice balance loss and that it is ACCELERATING.

What your comments vindicate is that you suffer from some kind of brain-wasting disease-induced memory loss, or just a convenient inability to remember.


VendicarD
3.7 / 5 (3) Oct 25, 2012
"What your comments vindicate is that you suffer from some kind of brain-wasting disease-induced memory loss, or just a convenient inability to remember." - Caliban

I think that both ParkerTard and UbVonTard suffer from schizophrenia and are off their medication.

ubavontuba
1 / 5 (5) Oct 25, 2012
In the plot provided, I see no change until 1900 at which point global warming became more pronounced and the oceans began to heat and expand.

http://upload.wik...Rise.png

"LOL! Vendibot is a blind chatbot. It can't even see that its own graph supports my assertion!" - Uba

It is unclear what Uba sees. He seems quite prone to self delusion.
LOL. Vendibot is so stupid it doesn't realize it just supported my statement!

Worse, it's now claiming significant AGW began in 1900! LOL!
ubavontuba
1 / 5 (6) Oct 25, 2012
Only in your wildist Tardboy Imagination.

"The article is clearly in agreement with what I said." - UbVonTard

Yup, Uba shows us that in the mind of the insane, black really is the same as white.

"This article clearly supports what I said then, too. I love vindication." - Uba
The Vendibot can't provide a proper argument, so it pretends to argue with ad hominems. How quaint.

Sadly, it looks like decent AI is a long ...long ...long way off (sigh).

VendicarD
4 / 5 (4) Oct 25, 2012
UbVonTard has for years been claiming that the earth is cooling and that glaciers are expanding.

And yet we see that from 1900 on, the ocean has been expanding as glacial melt water reaches the ocean and as the ocean expands due to global ocean warming.

"LOL. Vendibot is so stupid it doesn't realize it just supported my statement!" - UbVonTard

UbVonTard is clearly mentally diseased. I suspect schizophrenia.
ubavontuba
1.6 / 5 (7) Oct 25, 2012
It provides only partial support for your claim that ice balance loss was nil --and actually was in a POSITIVE trend, based on poorly quantized isostatic rebound data.
LOL. This claim is based on a stupid guess as to what's happening to the underlying rock. My claim was in direct reply to even stupider GRACE presumptions, which failed to even consider continental subsidence.

And, I wonder how long it will take them to realize this subsidence must be accommodated by an expansion of the globe.

This article clearly states that the rebound has been closely confined,
Based on what? How did they measure it?

but that there is still ice balance loss and that it is ACCELERATING.
Laser altimetry disagrees with this GRACE based assertion.

What your comments vindicate is that you suffer from some kind of brain-wasting disease-induced memory loss, or just a convenient inability to remember.
You just can't admit I was right all along, can you?

ubavontuba
1.6 / 5 (7) Oct 25, 2012
"What your comments vindicate is that you suffer from some kind of brain-wasting disease-induced memory loss, or just a convenient inability to remember." - Caliban

I think that both ParkerTard and UbVonTard suffer from schizophrenia and are off their medication.
Apparently, AGW propenents have simply run out of science.

Are personal attacks all they have now?

And still they wonder why people don't believe them!

Sad ...so sad (sigh).

ubavontuba
1.6 / 5 (7) Oct 25, 2012
Uba has for years been claiming that the earth is cooling and that glaciers are expanding.
Ooh. Now it resorts to blatant lies.

And yet we see that from 1900 on, the ocean has been expanding as glacial melt water reaches the ocean and as the ocean expands due to global ocean warming.
The sea level has been rising a lot longer than that!

"LOL. Vendibot is so stupid it doesn't realize it just supported my statement!" - Uba

Uba is clearly mentally diseased. I suspect schizophrenia.
Vendibot is clearly an inferior program. I suspect it's a highschool lab assignment.

Caliban
3 / 5 (4) Oct 26, 2012
uby,

There is no help for one who will not be helped.

Come to the Light. Come to the meds.

ubavontuba
1.6 / 5 (7) Oct 26, 2012
uby,

There is no help for one who will not be helped.

Come to the Light. Come to the meds.
Demonstrating once again how AGW propenents have simply run out of science.

And still they wonder why people don't believe them!

Sad ...so sad (sigh).

Caliban
2.3 / 5 (3) Oct 26, 2012
Demonstrating once again how AGW propenents have simply run out of science.

And still they wonder why people don't believe them!

Sad ...so sad (sigh).


uby,

There is no help for one who will not be helped.

Come to the Light. Come to the meds.

VendicarD
3 / 5 (2) Oct 28, 2012
Poor UbVonTard. Lying to hiself has become a way of life for him.

"And still they wonder why people don't believe them!" - UbVonTard

That and working as a carbon industry shill.
ubavontuba
1 / 5 (4) Oct 28, 2012
working as a carbon industry shill.
You mean I could get paid for this? How do I get that job?

I wonder, who put up the money to build the Vendibot? Who's paying the electric bill?

And, who built "Lite" ...it's little downranking-bot sidekick?

Some people need to find better hobbies.

VendicarD
3 / 5 (2) Oct 28, 2012
UbVonTard is caught telling at least one lie in every one of his posts. Dozens of lies every week.

As an Paid Oil Industry shill, that is his job.

http://youtu.be/XMTVGBGs_40
ubavontuba
1 / 5 (5) Oct 28, 2012
Uba is caught telling at least one lie in every one of his posts. Dozens of lies every week.

As an Paid Oil Industry shill, that is his job.
I answer to no one.

http://youtu.be/XMTVGBGs_40
Although I do not agree with the politicization of this issue, this is an excellent video.

For me, the issue is strictly about the quality of the science. The science on this issue is genuinely poor. If it wasn't, I couldn't find the blaringly obvious faults I regularly find and point out here.

So, who do you answer to?

VendicarD
3 / 5 (2) Oct 28, 2012
"I answer to no one." - UbVonTard

Just your political puppet masters.

Hahahahahahahah.... You prove daily that you haven't got a clue as to what science is, how it works, or what it's about.

"For me, the issue is strictly about the quality of the science. " - UbvonTard

Poor UbVonTard. He is the third most ignorant Carbon Industry Shill on Usenet, and doesn't even know what a laughing stock he has become.
ubavontuba
1 / 5 (4) Oct 29, 2012
Just your political puppet masters.

Hahahahahahahah.... You prove daily that you haven't got a clue as to what science is, how it works, or what it's about.

Poor Uba. He is the third most ignorant Carbon Industry Shill on Usenet, and doesn't even know what a laughing stock he has become.
Says the idiot chatbot which didn't even know "it's" is a contraction of "it is." LOL

Vendibot is clearly an inferior program. I suspect it's a highschool lab assignment. LOL

VendicarD
3.7 / 5 (3) Oct 29, 2012
UbVonTard has been claiming for over a year that Antarctic ice mass is increasing.

Yet the science reported by this article claims the exact opposite.

"We're now confident it is shrinking," says Professor King, currently on secondment at the University of Tasmania, Australia." - UbVonTard

All I see coming from UbVonTard, day after day after day is a non stop stream of lies.

Who pays him to come here and tell these serial lies?
ubavontuba
1 / 5 (3) Oct 29, 2012
Who pays (uba) to come here...?


Who pays the Vendibot's bills?

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