Antarctic ice shelves rapidly thinning

Antarctic ice shelves rapidly thinning
Eighteen years of change in thickness and volume of Antarctic ice shelves. Rates of thickness change (m/decade) are color-coded from -25 (thinning) to +10 (thickening). Circles represent percentage of thickness lost (red) or gained (blue) in 18 years. The central circle demarcates the area not surveyed by the satellites (south of 81.5ºS). Original data were interpolated for mapping purposes. Background is the Landsat Image Mosaic of Antarctica (LIMA). Credit: Scripps Institution of Oceanography, UC San Diego

A new study led by Scripps Institution of Oceanography at UC San Diego researchers has revealed that the thickness of Antarctica's floating ice shelves has recently decreased by as much as 18 percent in certain areas over nearly two decades, providing new insights on how the Antarctic ice sheet is responding to climate change.

Data from nearly two decades of satellite missions have shown that the volume decline is accelerating, according to a study published on March 26, 2015, in the journal Science and supported by NASA. Scripps graduate student Fernando Paolo, Scripps glaciologist Helen Amanda Fricker, and oceanographer Laurie Padman of Earth & Space Research (a non-profit institute specializing in oceanography research) constructed a new high-resolution record of thickness based on satellite radar altimetry missions of the European Space Agency from 1994 to 2012.

Merging data from three overlapping missions, the researchers identified changes in ice thickness that took place over more than a decade, an advancement over studying data from single missions that only provide snapshots of trends.

Total ice shelf volume (mean thickness multiplied by ice shelf area) across Antarctica changed very little from 1994 to 2003, then declined rapidly, the study shows. West Antarctic ice shelves lost ice throughout the entire observation period, with accelerated loss in the most recent decade. Earlier gains in East Antarctic ice shelf volume ceased after about 2003, the study showed. Some ice shelves lost up to 18 percent of their volume from 1994 to 2012.

"Eighteen percent over the course of 18 years is really a substantial change," said Paolo. "Overall, we show not only the total ice shelf volume is decreasing, but we see an acceleration in the last decade."

While melting ice shelves do not contribute directly to sea-level rise, the researchers indicate that there is an important indirect effect."The ice shelves buttress the flow from grounded ice into the ocean, and that flow impacts sea-level rise, so that's a key concern from our new study," said Fricker.

Under current rates of thinning, the researchers estimate the restraining the unstable sector of West Antarctica could lose half their volume within the next 200 years.

Antarctic ice shelves rapidly thinning
Schematic diagram of an Antarctic ice shelf showing the processes causing the volume changes measured by satellites. Ice is added to the ice shelf by glaciers flowing off the continent and by snowfall that compresses to form ice. Ice is lost when icebergs break off the ice front, and by melting in some regions as warm water flows into the ocean cavity under the ice shelf. Under some ice shelves, cold and fresh meltwater rises to a point where it refreezes onto the ice shelf. Credit: Helen Amanda Fricker, Professor, Scripps Institution of Oceanography, UC San Diego
"This work demonstrates the power of satellite observations to understand change in the great polar ice sheets," said Thomas Wagner, Program Manager for Cryospheric Sciences at NASA Headquarters. "And with data spanning decades, we can understand some of the most important changes and their implications for sea-level rise."

Fricker said future studies will concentrate on the causes behind changes in ice shelf volume, including the effects of the atmosphere and ocean.

"We're looking into connections between El Niño events in the tropical Pacific and changes in the Antarctic ice sheet," said Paolo. "It's very far apart but we know that these teleconnections exist. That may ultimately allow us to improve our models for predicting future ice loss."


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Achilles' heel of ice shelves is beneath the water, scientists reveal

More information: "Volume loss from Antarctic ice shelves is accelerating," www.sciencemag.org/lookup/doi/ … 1126/science.aaa0940
Journal information: Science

Citation: Antarctic ice shelves rapidly thinning (2015, March 26) retrieved 20 June 2019 from https://phys.org/news/2015-03-antarctic-ice-shelves-rapidly-thinning.html
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Mar 26, 2015
It was true these were shedding more rapidly as well. This should still be happening because of catastrophic failure from ice.

Mar 26, 2015

"Total ice shelf volume (mean thickness multiplied by ice shelf area) across Antarctica changed very little from 1994 to 2003"

That's a fairly long time for Global Warming to have virtually no effect.

Mar 26, 2015
I find it interesting that every time there is an article regarding the thinning Antarctic ice, Greg Tyler feels the need to post his misunderstandings of CO2 driven warming vrs mechanical warming. It does not matter how many times or ways it is pointed out that he is wrong, he just plunges ahead and says the same thing on the next article that comes along. Reminds me of Zephyr in many ways.

Mar 26, 2015
Wow, all that melting going on and yet, Antarctic seasonal sea ice has expanded to the highest levels ever recorded, even during the "warmest year ever".

Mar 26, 2015
SO, you say that fatuously, yet if ice cools water, and there is a temperature drop, then more ice can form.

I am not saying this is happening all the time, but energy is conserved, and heat is being transferred. There is alot of possibility in the tradespace, due to the heat capacity of water, ice and water vapor.

Mar 26, 2015
Wow, all that melting going on and yet, Antarctic seasonal sea ice has expanded to the highest levels ever recorded, even during the "warmest year ever".

Just shows you what fresher water and stronger winds can do. Meanwhile it'll have all melted back by now.

Mar 26, 2015
This article implies 18% loss over 18 years, then goes on to make a prediction that 50% will melt in 200 years with the accelerating ice melt. Somehow, this math does not add up. Based on current trends, I would expect that 50% melt would take less than 50 years. Am I missing something here?

Mar 26, 2015
This article implies 18% loss over 18 years, then goes on to make a prediction that 50% will melt in 200 years with the accelerating ice melt. Somehow, this math does not add up. Based on current trends, I would expect that 50% melt would take less than 50 years. Am I missing something here?


Yes, the ice loss is not linear - its a compounding problem.

Mar 26, 2015
Well, look at that, the evil CO2 is only melting the ice under which their is intense geothermal activity. But then, in AGW Cult "science" CO2 possess magical properties.

Mar 26, 2015
@antig

Where are your links to "intense geothermal activity?

That's right, there aren't any.

Mar 26, 2015
This article implies 18% loss over 18 years, then goes on to make a prediction that 50% will melt in 200 years with the accelerating ice melt. Somehow, this math does not add up. Based on current trends, I would expect that 50% melt would take less than 50 years. Am I missing something here?

I agree that it could use some explanation, but consider that, first of all, the article is clear that the ice shelves in the west had lost up to 18% - many lost much less. Secondly, as the 1st figure shows and as Maggnus mentions, the ice loss is non-linear. And third, keep in mind that most scientists are very conservative in their statements.

Mar 26, 2015
Gold nuggets rapidly becoming accessible. Huzzah.

Mar 27, 2015
Vietvet, here is your link to geothermal activity:
http://www.livesc...ers.html

The area of melting ice referred to in the above link may be in the same area Scripps is studying. The Scripps press release is a little vague about the location. Ice on the opposite side of the continent, meanwhile, is growing thicker which suggests the melting in the west is likely due to a combination of volcanism and a warm ocean current. At any rate, 20 years of data is not proof of any causative factor except natural variability.

Mar 27, 2015
Wow, all that melting going on and yet, Antarctic seasonal sea ice has expanded to the highest levels ever recorded, even during the "warmest year ever".

There is a helpful figure, with labels. You may notice that the thinning ice shelves mentioned in the article title are glacial ice coming off the continent, while sea ice is what forms on the sea when seawater freezes. Unless you can show that amounts of ice in ice shelves and in sea ice must be positively correlated, you have no argument, yet I have never seen you bother trying to explain the connection.

Mar 27, 2015
Anonym,
Actually, volcanism contributes very little to the accelerating melting of Antarctica. This is for two reasons: 1) there's no evidence of an increase in volcanism that would be required to accelerate the melting, and 2) The amount of heat from the volcanoes is much too small to explain the current melt (https://news.vice...ice-caps ). An interesting quote from that link:
geothermal heating contributes to a few millimeters of melting annually, compared to rising sea temperatures which can trigger rates of up to 100 meters each year.

I think the scientists wanted to put out this article because there were a large number of anti-science people that were using the study to claim volcanoes had a significant effect on the melting of Antarctica.

Mar 27, 2015
As for "natural variability", since the loss of ice on Antarctica is primarily due to warmer oceans and, since there is an enormous amount of evidence showing that the warming of the oceans is due to the current warming (primarily caused by increases in CO2 levels) and, since there is no evidence of any variability to explain the melting, it seems a stretch to bring up natural variability.

Mar 27, 2015
This article implies 18% loss over 18 years, then goes on to make a prediction that 50% will melt in 200 years with the accelerating ice melt. Somehow, this math does not add up. Based on current trends, I would expect that 50% melt would take less than 50 years. Am I missing something here?


Yes, the ice loss is not linear - its a compounding problem.


Compounding problem, as in compound interest type of deal? Like an acceleration? Sorry, I am still not quite understanding here. If the melt is accelerating as it has been shown to be, then wouldn't that equate to greater ice loss in future melt events? Or am I wrong in assuming that the 18% figure represents 18% volume of current ice?

Mar 29, 2015
Water_Prophet stated
SO, you say that fatuously, yet if ice cools water, and there is a temperature drop, then more ice can form
Obviously it depends on the temperature of the ice to start with and the dynamics, something your claimed water bowl cannot address !

Water_Prophet claimed
There is alot of possibility in the tradespace, due to the heat capacity of water, ice and water vapor
Depends & as a claimed "Physical Chemist" u know how to quantify this AND especially so craft a proper experiment to show it and be able to confirm why a brass water bowl with a candle is rubbish. But in all this time & since your arbitrary claims why is it u cannot prove any of your claims ?

Eg
Y is your CO2's effect claim of 0.00009W/m^2 some 16,666x Lower than wiki's 1.5W/m^2 ?

AND

Y aren't your claimed 4 uni degrees including "Physical Chemistry" on your facebook page ?
https://www.faceb...er/about

Mar 31, 2015
I am no geophysicist, but volcanic activity has been increasing, so it's possible.
Funny how volcanism keeps undermining AGWing CO2.
Mona Loa is on top of an increasingly active volcano, and antarctica...

Mar 31, 2015
More than 2/3 of the Antarctic is gaining/not losing ice. The only place melting is directly above where there is geothermal activity and yet the AGW Chicken Littles can't see the fraud that is their cult.

Apr 01, 2015
Water_Prophet claimed
I am no geophysicist, but volcanic activity has been increasing, so it's possible
Evidence for your claim please AND quantification of the amount in Watts/m^2 over what region ?

Funny Water_Prophet undermines his position with
Funny how volcanism keeps undermining AGWing CO2
Not being able to support your many claims makes you appear immature, naive & unlikely u have "4 technical degrees" as claimed ?
Institute & yr of degrees started please ?

Water_Prophet claimed
Mona Loa is on top of an increasingly active volcano..
Since last eruption was 1984 how is that "increasing" ? And which way does the wind blow ?

Any proof of ANY your claims ever by now there are so very many ?

Explain please then why the CO2 has seasonal noise or are you claiming Mauna Loa has too ?

Water_Prophet with so many claims, his worst is that CO2's effect is a low 0.00009W/m^2 whilst he claims wiki at 1.5W/m^2 is in great agreement !

so sad

Apr 01, 2015
antigoracle claimed
More than 2/3 of the Antarctic is gaining/not losing ice
Gravitational surveys' show a nett mass lost, not gained. Evidence to back your claim please ?

antigoracle claimed
The only place melting is directly above where there is geothermal activity and yet the AGW Chicken Littles can't see the fraud that is their cult.
No. Satellite data
http://www.volcan...ica.html

Look at article too !

antigoracle, just like ubavontuba & Water_Prophet u shoot yourselves dumbly so often, wonder if u are intimate & related or intimately related LOL !

antigoracle claimed
Well, look at that, the evil CO2 is only melting the ice under which their is intense geothermal activity. But then, in AGW Cult "science" CO2 possess magical properties
U are a very stupid liar, CO2's thermal properties have been well known for >100 yrs.

Proof CO2's radiative forcing < 1.5W/m^2 please ?

Making idle unsupported claims makes u look bad !

Apr 01, 2015
Water_Prophet uttered
It was true these were shedding more rapidly as well. This should still be happening because of catastrophic failure from ice
What does this even mean, especially "catastrophic failure from ice" ?

R u feebly trying to say the antarctic failed from the ice - eh ?

Or your mixed up use of 'failure' implies antarctic is failing "as a continent" from failure of ice - what ?

You definitely don't write like anyone with "4 technical degrees" !

Why aren't they listed on your facebook page, best u did is high school, so sad
https://www.faceb...er/about

Key claim u made recently is CO2's radiative forcing of 0.00009 W/m^2, why please can't u show why u have made it so low, it appears faked & whopping 16,666 x lower than wikis - Why ?
https://en.wikipe...ings.svg

Making claims refusing to substantiate them makes makes u appear anti-intellectual.

Why can't you prove ANY of your claims, whopper ?

Apr 01, 2015
Alche/WaterDummy said:

I am no geophysicist, but volcanic activity has been increasing, so it's possible.
Funny how volcanism keeps undermining AGWing CO2.
Mona Loa is on top of an increasingly active volcano, and antarctica...


Yes, we all know you are not a geophysicist. You do not have the math and physics background to understand geophysics.

As an example, you are making a comment about the "stupidity" of the scientists who put their sampling system on a volcano. You seem to think they didn't "notice." While that might be true for you, they are real scientists and design much better experiments than you can.

Your idiocy is that you seem to think they sample from only one place. I have shown you that they sample from all over the world. You just choose to ignore the facts.

http://www.esrl.n...ggrn.php

Here is the link again. Do you really think we don't know you are aware of the other sampling locations?

Apr 01, 2015
I have to say a bit more on the comment about Mona Loa being a volcano that Alche/WaterDummy thinks gives faulty CO2 measurements due to the volcano producing CO2.

Alche/WD's comment means that he didn't even look to see if there were more measurement locations than Mona Loa, and it is clear that measurements are being taken all over the globe. It also indicates he never looked at the techniques pioneered by Keeling to continuously monitor CO2 and compensate for the CO2 produced by the volcano. Here is the approach they use. Just point out where they are doing it wrong. Why did you not even look at where the measurements are made and how they make sure they are right?

http://www.esrl.n...nts.html

Apr 01, 2015
Hey Mike, were you born this stupid or dropped as a baby?
Take a gander at the image at the top of this article. Less than a 1/3 of the Antarctic shows melting and it's directly above known geothermal activity.

Apr 01, 2015
thermy, The reason-ability of the scientists is not the issue. Why anyone would put a sampling station on such a dirty source REQUIRING processing is the devil's cane. And a laughable one only the gullible would believe, when there are so many possible pristine locations.
Any one knows you need a known to compensate, most increasingly active volcanoes aren't known as "Old Faithful."

Apr 01, 2015
thermy, The reason-ability of the scientists is not the issue. Why anyone would put a sampling station on such a dirty source REQUIRING processing is the devil's cane. And a laughable one only the gullible would believe, when there are so many possible pristine locations.
Any one knows you need a known to compensate, most increasingly active volcanoes aren't known as "Old Faithful."


Alche/WDummy notes that he still believes that taking CO2 data on Mona Loa must lead to errors. However, I passed on the location of more than 100 sites all over the world that sample the atmosphere for CO2.

How is it possible for Alche/WaterDummy to state: "And a laughable one only the gullible would believe, when there are so many possible pristine locations." when I have shown him that data are taken at many other sites and they correlate well with Mona Loa. Alche: Do you really think that the location was chosen with the scientists unable to recognize it as an active volcano?

Apr 01, 2015
Odd you call me dumb.
But you defer to Skeptiscience, a website designed by a failed physics major turned artist, and somehow conclude that he knows... something.

You don't understand how ridiculous and sorry, dumb, by being referent to such a person. You might as well be referent to me... You'd have more clout. Sorry, bub, it is just true.

I can produce both facts and experiments justifying my point. Aka fossil fuels contributing >1/10 of the energy needed to change climate, dramatically, therefore, sufficient energy to change climate. I can show the temperature changes in the Earth are linear with GDP.
Both theoretically and experimentally I can show water vapor is more significant than CO2.

These, whether you agree with there sufficiency, are strong and positive factors.

Can you show a single strong positive correlation with CO2? (CO2's correlation to temperature is weaker than GDPs and thus fossil fuel consumption).

Just one strong metric, sans hand waving?

Apr 02, 2015
antigoracle claimed
Take a gander at the image at the top of this article. Less than a 1/3 of the Antarctic shows melting and it's directly above known geothermal activity
Your attempt at immature offense betrays your lack of intelligence, and you only go a small step to any move to understand an issue, exactly like Water_Prophet :-(

Look at the locations, correlate them with their status vs active, inactive & any heat release records and in any case notice all the locations marked with ice thinning are coastal - doh ! ie The issue of contact with the sea is OBVIOUSLY the main major factor but, hey don't stop there and be feeble, extend your claim to geothermal emission data...

antigoracle unfortunately making idle blurts & superficial claims tells us lots about you, back to school !

Apr 02, 2015
Water_Prophet
Odd you call me dumb
Evidence is substantial:-

1. Your writing is not commensurate with anyone of university education
2. You have nil understanding of "Experimental Methodology"
3. You have nil understanding of instrumentation & data collection management, risk assessment
4. Claims are sporadic & not well thought through, none of which you can prove !

I claim openly and publicly you are a LIAR & CHEAT !

Lets start with proving your claim of "4 technical degrees", which institute & when started please ?

AND why is your highest educational achievement ONLY high school & so long ago as per your facebook page ?
https://www.faceb...er/about

Then we move on to all your stupid claims re CO2.
Y is your CO2's effect claim of 0.00009W/m^2 some 16,666x Lower than wiki's 1.5W/m^2 ?
https://en.wikipe...ings.svg

Water_Prophet, so sad, no-one with a good IQ would ever use u as a reference :-(

Apr 02, 2015
Water_Prophet
Odd you call me dumb
Evidence is substantial:-

Well, WP has claimed that "CO2 levels should not be able to go below the true average." So in WP math, you can't have values below the average. Therefore, WP's IQ cannot be below average. QED ;)

So we know that:
1. WP has difficulty with basic math.
2. WP doesn't understand the greenhouse effect.
3. WP can't find anything wrong with the arguments presented at SkepticalScience, so he resorts to the logical fallacy of ad hominem to try to discredit the site.

So errors in math, science, and logic. It's all good. ;)

Apr 02, 2015

I can produce both facts and experiments justifying my point. Aka fossil fuels contributing >1/10 of the energy needed to change climate, dramatically, therefore, sufficient energy to change climate. I can show the temperature changes in the Earth are linear with GDP.
Both theoretically and experimentally I can show water vapor is more significant than CO2.

These, whether you agree with there sufficiency, are strong and positive factors.

Can you show a single strong positive correlation with CO2? (CO2's correlation to temperature is weaker than GDPs and thus fossil fuel consumption).

Just one strong metric, sans hand waving?


Sorry, these were buried under a malicious information warfare attack.

Apr 03, 2015
Water_Prophet claimed
Sorry, these were buried under a malicious information warfare attack
Eh ?
Crap & nonsense !

R u now claiming; someone hacked into your pc, re-sent your phys.org messages from many hours ago all at once, bypassed phys.org flood control & STILL u have TIME to edit ALL of them so could ADD text:-

"Sorry, these were buried under a malicious information warfare attack"

That is ALSO beyond any credibility u had left, for the simple reason there are moderately complex sequences which would have to be defeated AND your ability to edit posts - LOL !

Instead it looks FAR more like a twisted attempt to garner sympathy !

Why not INSTEAD qualify all your claims Eg top are

- CO2 of only 0.00009 W/m^2
- Wiki is in "great agreement" with 0.00009 when theirs is 1.5 - ie 16,666 greater than yours FFS how?
- Those "4 technical degrees"
- Your water bowl model of ice works despite all its experimental failings
- Business uses your calculations

so sad

Apr 05, 2015
And another susbstanceless info attack, designed to distract from the inconvenient reality of my previous posts.

Apr 05, 2015
Water_Prophet claimed
And another susbstanceless info attack, designed to distract from the inconvenient reality of my previous posts
Your stupid tacics are immensely transparent, you STILL haven't proven ANY of your claims or even taken ANY steps to quantify them yet YOU post claims or 'warfare' YET you had time to edit them from the SAME account - You appear delusional & yet again try to obfuscate ANY of your claims ie:-

Y is your writing NOT commensurate with those claiming "4 technical degrees" as u do ?
Which institute & what years started please ?

Y aren't your uni degrees including claim of "Physical Chemistry" on your facebook page ?
https://www.faceb...er/about

Y is your CO2's effect claim of 0.00009W/m^2 some 16,666x Lower than wiki's 1.5W/m^2 ?
https://en.wikipe...ings.svg

Y can't U prove your claim "business uses your results" ?

Apr 05, 2015
Antarctic ice shelves rapidly thinning
This is what the Antarctic ice shelves are doing at the end of winter at northem hemisphere each year. I know, it may look strange and paradoxical, but it's usually replaced with the opposite effect each autumn...;-) Apparently the Antarctic ice does nothing exceptional in terms of long-term average, it just does it faster.

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