Researchers Provide Detailed Picture of Ice Loss Following Collapse of Antarctic Ice Shelves
An international team of researchers has combined data from multiple sources to provide the clearest account yet of how much glacial ice surges into the sea following the collapse of Antarctic ice shelves.
The work by researchers at the University of Maryland, Baltimore County (UMBC), the Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, Centre National de la Recherche Scientifique at the University of Toulouse, France, and the University of Colorado’s National Snow and Ice Data Center, Boulder, Colo., details recent ice losses while promising to sharpen future predictions of further ice loss and sea level rise likely to result from ongoing changes along the Antarctic Peninsula.
The Larsen B ice shelf began disintegrating around Jan. 31, 2002. Its eventual collapse into the Weddell Sea remains the largest in a series of Larsen ice shelf losses in recent decades, and a team of international scientists has now documented the continued glacier ice loss in the years following the dramatic event. NASA’s MODerate Imaging Spectroradiometer (MODIS) captured this image on Feb. 17, 2002. (Credit: MODIS, NASA’s Earth Observatory) › Larger image
“Not only do you get an initial loss of glacial ice when adjacent ice shelves collapse, but you get continued ice losses for many years — even decades — to come,” says Christopher Shuman, a researcher at UMBC’s Joint Center for Earth Systems Technology (JCET) at NASA’s Goddard Space Flight Center, Greenbelt, Md. Shuman is lead author of the study published online July 25 in the Journal of Glaciology. “This further demonstrates how important ice shelves are to Antarctic glaciers.”
An ice shelf is a thick floating tongue of ice, fed by a tributary glacier, extending into the sea off a land mass. Previous research showed that the recent collapse of several ice shelves in Antarctica led to acceleration of the glaciers that feed into them. Combining satellite data from NASA and the French space agency CNES, along with measurements collected during aircraft missions similar to ongoing NASA IceBridge flights, Shuman, Etienne Berthier, of the University of Toulouse, and Ted Scambos, of the University of Colorado, produced detailed ice loss maps from 2001 to 2009 for the main tributary glaciers of the Larsen A and B ice shelves, which collapsed in 1995 and 2002, respectively.
The Landsat Image Mosaic of Antarctica (LIMA) provides this “flyover” view of the Larsen Ice Shelf’s long reach out into the Weddell Sea. (Credit: LIMA)
“The approach we took drew on the strengths of each data source to produce the most complete picture yet of how these glaciers are changing,” Berthier said, noting that the study relied on easy access to remote sensing information provided by NASA and CNES. The team used data from NASA sources including the MODerate Imaging Spectroradiometer (MODIS) instruments and the Ice, Cloud and land Elevation Satellite (ICESat).
The analysis reveals rapid elevation decreases of more than 500 feet for some glaciers, and it puts the total ice loss from 2001 to 2006 squarely between the widely varying and less certain estimates produced using an approach that relies on assumptions about a glacier’s mass budget.
The authors’ analysis shows ice loss in the study area of at least 11.2 gigatons (11.2 billion tons) per year from 2001 to 2006. Their ongoing work shows ice loss from 2006 to 2010 was almost as large, averaging 10.2 gigatons (10.2 billion tons) per year.
An animation showing ice edge changes for the Larsen B ice shelf and its adjacent tributary glaciers can be viewed at http://svs.gsfc.nasa.gov/goto?3803.
Related Links
› Larsen B Ice Front Changes 2001-2009 (NASA SVS)
› Animation of Larsen B collapse (NASA Earth Observatory)
› Before and after Larsen A comparison (NASA SVS)
Goddard Release No. 11-046
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UPDATE: The press liaison at NSDIC wrote to complain about the “worse than we thought” title.
Dear Mr. Watts,
We noted that you republished a NASA/NSIDC press release regarding a new Journal of Glaciology paper. In the headline of your post, the phrase “worse than we thought” is in quotation marks. This makes it appear as if it is a quote from the press release, and a statement by the researchers. We request that you remove the quotation marks so that it is clearer that this is your headline.
NASA and NSIDC scientists are always willing to grant interviews to journalists if you have questions about their research.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Katherine Leitzell Science Communications National Snow and Ice Data Center Cooperative Institute for Research in Environmental Sciences 449 University of Colorado Boulder, CO 80309
I replied:
Dear Ms. Leitzell
The “worse than we thought” is a cliché that reverberates through the climate science community and is well understood by my readers. It is a satirical statement, intending to convey the oft repeated science by press release position that climate change is an escalating series of alarming press releases, each worse that the other.
Quotation marks also serve to delineate a satirical statement, and is often visualized in person by the person taking two fingers (index and middle) and bending them. It has also been described as being a snowclone in the vein of.
X is “worse than we thought”.
Thus, since satire is protected by free speech, and this is a fair use application of a publicly funded study and press release, the headline stands. I will however make a footnote at the bottom of the story stating that NSIDC has complained, and the title are my satirical words. You should know that the press release is not being well received. http://tomnelson.blogspot.com/2011/07/antarctic-ice-allegedly-declining-at.html
Thank you for your consideration.
Anthony Watts
For R. Gates and Brian…
====
In 2005 data from NASA’s Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide “ice caps” near Mars’s south pole had been diminishing for three summers in a row.
http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html
====
South pole, 1969:
http://www.windows2universe.org/mars/images/mar7app.gif
South pole (right) – circa 2000:
http://www.windows2universe.org/mars/places/mars_hubble_both_poles_big.jpg
“Additionally, in geologic time scales, the ice caps may grow or shrink due to climate variation. ”
http://en.wikipedia.org/wiki/Polar_ice_cap
Is the warming observed on Mars misanthropic too?
I’m all for going green and for actually starting to care for the Earth.
I’m reading often about the melting Poles, and how much ice has already been lost.
I also read prognostics of how much the sea levels will rise when/if the ice melts.
Now… I’m putting these two pieces of information together and… notice that no one has had his city disappear in the sea, despite the mega-melt at both Poles.
Therefore… something is wrong with the information and/or calculations that we are being fed.
**sigh**
I hate to get lied to and not knowing which side is telling me what lie.
rbateman says:
July 26, 2011 at 9:00 pm
R. Gates says:
July 26, 2011 at 7:58 pm
Oh, you mean THIS picture that I remembered from back when Science was respected, and was bringing us views of ours and other worlds never imagined:
http://www.robertb.darkhorizons.org/0857806.jpg
THAT picture put finished to the wild speculation of AGW causing ice-free holes in the Arctic in winter.
____
Uh, since polynyas have been known about for centuries and are formed through sensible or latent heat mechanisms (i.e. warm water upwelling or wind and current driven). I don’t recall ever reading that their existence would be caused by AGW. Please cite your research to back up this statement. They can form pretty much anywhere in the Arctic.
I know the submarine photo is a favorite among certain skeptics, but alas, it proves nothing scientific except that polynyas can make great photo ops for submarines.
khwarquackers;
R. Gates and Brian? You talkin’ t’ me? If you conceive of any overlap between the views of RG and myself, you’re smoking something weird.
And “misanthropic” doesn’t mean what you seem to think it does. Though it has a significant pertinence to AGW theory!
Interstellar Bill:
Seems you enjoy political rants more than science. Maybe Glenn Beck could use a new assistant Producer?
Amazing how sats can now let us study these things so easily in one of the remotest and toughest places in the world.
Good stuff,
Brian H says:
July 26, 2011 at 10:25 pm
khwarquackers;
R. Gates and Brian? You talkin’ t’ me? If you conceive of any overlap between the views of RG and myself, you’re smoking something weird.
And “misanthropic” doesn’t mean what you seem to think it does. Though it has a significant pertinence to AGW theory!
____
I think he was talking to a different Brian, and probably thought this person had some sympathetic response to my posting of actual scientific research, based on this response:
Brian says:
July 26, 2011 at 6:19 pm
It’s amazing that people will continue to ignore Gates evidence.
There is enough proof out there, but people want to continue in their own little fantasy land.
___
To which I would respond, that no, they’re not in their own little fantasy land, but the fantasy land call Groupthink.
rbateman says:
July 26, 2011 at 9:15 pm
You have a very important point there, Chris.
What the hell is Space Administration doing studying Antarctic Ice? Sounds suspiciously like money being wasted. Last I heard, Antarctica still has Terran atmophere over it, and it is still attached to planet Earth.
I don’t mind seeing new eye-popping pics taken by satellites that they launch, but the studying part is best left to the proper researchers in thier respective fields.
=================================
Right on, Robert. Sort of like the hastily-drawn and unscientific G.I.Z.Z. temperature record they keep.
How does the GISS “database” aid the study of space, space flight, and aeronautics?
Seems to me that should be under NOAA but who am I to judge.
With ideologues like Hansen at the helm…aggressively diverting tax-robbed dollars toward their interests…it is no wonder the space shuttle program has been shelved.
Where is the NASA of our youth?
Chris
Norfolk,, VA, USA
Interstellar Bill says:
July 26, 2011 at 9:31 pm
To R. Gates: “You babble endlessly about hypothetical ‘tipping points’ while not even one actual tipping point in Earth’s past has ever been computer-modeled”
____
Tipping points are created in systems existing in spatio-temperal chaos, and as such, can’t really be modeled, but only seen after the fact. We have in fact seen tipping points many times in earth’s past, when the climate shifted suddenly, even violently. Witness, for example, the Younger Dryas cooling, when, in a matter of a just a few years, the global climate shifted from an interglacial kind of warmth to a glacial period. Some sort of “tipping point” was crossed, that totally altered earth’s atmospheric and ocean circulation patterns..
R. Gates says:
July 26, 2011 at 10:23 pm
I know the submarine photo is a favorite among certain skeptics, but alas, it proves nothing scientific except that polynyas can make great photo ops for submarines.
===============================
Oh…so you DO admit to possible natural causes of ice changes in the arctic?
You can’t have it both ways, Gates.
One day, a huge polynya in the early 1960s in the Arctic, and it is from natural causes.
After 1979, with satellites, it all becomes anthropogenic.
I smell a rat.
This photo may “prove nothing”…as you say….but it IS interesting, but even then…that is a side issue.
Until you can do better (and yes, the burden of proof is on squarely on your side), the term “natural variability” is still the name of the game.
Chris
Norfolk, VA, USA
Has the announcement that Antarctic ice is gaining mass downward been taken into account, or at least mentioned, in any other recent papers, studies, or whatever?
— Ed
There are three types of ice on and around Antarctica.
The icecap and glaciers on land above sea level that is flowing slowly of the continent.
The ice from the land that is resting on sea-bed. The seaward end of these ice shelves calves icebergs at a rate that matches the rate ice flows onto the shelf from the land.
The sea ice that forms during the winter and is frozen sea surface.
The seasonal cycle of sea ice around the Antarctic coast is a regional weather driven process and largely irrelevant to the melting of the land and ice-shelf ice.
The ice-shelves have been in existence since at least the last inter-glacial maximum in the Eemian. They buttress the glacier flow from the land and when a shelf collapses the glacier flow increases. This results in greater rates of iceberg calving from the shorter ice shelf that is left.
The continuing shrinkage of the ice shelves and measured increase in glacier flow is the mechanism that raises sea level. The shrinkage of the ice shelves is driven by warming oceans, as there is no prospect of ocean temperatures falling over the next few decades more ice will be lost from Antarctica and sea level will rise.
The amount may be small, but the rate is unpredictable at the higher end of possibilities.
Researchers say the shrinking ice surface can significantly increase the cases of cannibalism in polar bears.
>>Mike Jowsey says: July 26, 2011 at 10:37 am
>>By the way, R Gates – Accelerating Ice mass loss in both Antarctica
>>and Greenland is undeniable.
>>Check the stats before hyperventilating too much:
>> http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
That is probably the worst cherry-pick ever. We are looking at climate issues, not weather.
Yes, over the last TWO years antarctic sea ice has reduced, but since 1979 it has put on 0.5 million sq km.
.
R. Gates
It’s difficult to measure large continental ice sheets (if not ultimately impossible). But there’s a simple way to see if they are losing mass overall or not. Check to see if the steady 2mm/yr, or so, global sea rise due to thermal expansion is being added to. It isn’t. (See about half way down this page.)
If ice shelves and sea icebergs are the measure of castastropic climate change, then the berg that sank the Titanic must have been a result of castastropic climate change in the 1910’s.
Glacial advance. How surprising is it that the rates are much faster than previously imagined by those who never bothered to check thier history?
@- Paul Clark says:
July 27, 2011 at 1:41 am
“It’s difficult to measure large continental ice sheets (if not ultimately impossible).”
Measuring the changes in the gravity they exert is quite effective as seen from the GRACE satellite data.
” But there’s a simple way to see if they are losing mass overall or not. Check to see if the steady 2mm/yr, or so, global sea rise due to thermal expansion is being added to. It isn’t. (See about half way down this page.)”
What the sea level graphs show is a seasonal/yearly variation of around 10mm. Trying to derive a trend from the last year is suspect to say the least. The graphs show a trend over decades and that trend is evident over the last century. There is no reason to expect this rising trend to reverse, it closely follows temperature and that shows no indication of returning to 1980s levels.
We recently were asked to help with a little web research project. This post inspired me to do it again.
Google “worse than we thought” and you get things like:
http://earthfirst.com/7-environmental-problems-that-are-worse-than-we-thought/
http://earthfirst.com/7-more-environmental-problems-that-are-worse-than-we-thought/
http://www.celsias.com/article/oceans-far-worse-we-thought-toxic-combination-over/
http://www.fastcompany.com/1685843/climate-change-is-worse-than-we-thought
http://www.ecademy.com/node.php?id=165488
http://vox-nova.com/2009/09/25/worse-than-we-thought/
http://www.grinzo.com/energy/2010/11/10/himalayan-glacier-melt-its-worse-than-we-thought/
http://wottsupwiththat.com/2011/05/06/more-arctic-sea-level-%E2%80%9Cworse-than-we-thought%E2%80%9D-scare-stories/ (doesn’t really count)
http://sierravoices.com/2011/07/climate-change-it-may-be-worse-than-we-thought/
http://www.washingtontimes.com/weblogs/watercooler/2010/feb/15/al-gore-climate-crisis-unfolding-our-eyes/
http://www.tnr.com/blog/the-vine/amazon-deforestation-even-worse-we-thought
http://inhabitat.com/great-pacific-garbage-patch-is-worse-than-we-thought/
http://current.com/community/90076793_is-climate-change-worse-than-we-thought.htm
http://arstechnica.com/old/content/2008/11/acidic-oceans-faster-than-we-thought.ars
http://www.purifymind.com/Dioxin.htm
http://www.newsreview.com/reno/bpa-worse-than-we-thought/content?oid=1815753
http://www.treehugger.com/files/2008/08/ipcc-underestimates-impact-of-logging-on-climate-change.php
http://blogs.discovermagazine.com/80beats/2008/11/25/ocean-acidification-worse-than-the-big-problem-we-thought-it-was/
http://ecolocalizer.com/2009/09/02/global-warming-in-the-arctic-much-worse-than-we-thought/
http://efdl.cims.nyu.edu/publications/public_media/newscientist_sealevel_09.pdf
http://www.beatenetworks.com/blog/index.php?/archives/325-Green-Trends-Worse-Than-We-Thought.html (this one seems real)
http://www.colorado.edu/news/r/efcb5fcc44583874f06555c219320316.html
http://sustlife.com/blog/climate-change/climate-change-worse-than-we-thought-global-dimming.html
http://www.spur.org/blog/2009-12-18/sea_level_rise_way_worse_we_thought_again
http://www.greenfudge.org/2009/11/09/methane-even-worse-greenhouse-gas-than-we-thought/
http://www.thegoodhuman.com/2006/05/24/is-global-warming-worse-than-we/
http://www.neutralexistence.com/blog/burning-coal-is-even-worse-than-we-thought/
http://www.theage.com.au/news/national/climate-worse-than-we-thought/2007/11/29/1196037074795.html
http://www.australianclimatemadness.com/2011/05/shock-its-all-worse-than-we-thought-sez-commission/ (some rare sanity)
http://www.carbonplanet.com/blog/2007/02/03/global-warming-is-worse-than-we-thought-but-its-not-too-late-for-us-to-act/
http://www.guardian.co.uk/politics/2007/feb/03/greenpolitics.science
It’s interesting to compare the older examples to the newer ones. It’s pretty clear the newer ones realize the audience is getting more skeptical. My favorite old one has the picture of several polar bears standing on a melting iceberg apparently surrounded by open ocean.
Apparently this scam will never end. I got 4,330,000 results.
@ur momisugly:izen July 27, 2011 at 2:18
Well there was an adjustment to the GRACE satellite altimetry recently by a factor of two as I understand it (a reduction by half of the previous estimate of ice loss.) It’s really an admission by NASA that they don’t know how to adjust for isostatic rebound by the continents after the last glaciation period. It’s guess work at best, therefore the sea levels, which are steady, are the best prognosticator.
Huge ice bergs are always breaking off Antarctica and quite honestly just Google. One in 2010
broke off because of a collision by one into another. There was worries that this could cause
danger to shipping but so far it hasn’t caused any problem. What happens naturally and normally. Remember Antarctic is subject to seismic activity also. There is an active volcano in Australian territory and quite honestly most of the ice shelves is where the animals live being mainly king penguins so they can get access to the sea easily and it is warmer there. They see the ice shelves breaking off and scream ‘global warming’ forgetting that this is quite normal for that part of the world and isn’t a sign of global warming.
Meanwhile, on the far side of Antarctica, is a feature that once was called Cape Amery, and is now called the Amery Ice Shelf. Ever hear of it? Of course not, because it keeps growing and growing. You will only hear of it when it sticks out too far, and cracks off.
There was a flurry of excitement back in 2003, when it seemed it might break off, but, drat it all, it didn’t. Wait until next year.
Link to 2003 excitement:
http://earthobservatory.nasa.gov/IOTD/view.php?id=2870
Ice shelves are very vulnerable to storm activity. Since the ice is supported by the underlying sea water any storm wave action tends to start vertical shelf movement causing cracking and failure. A leap to accuse climate change for this shelf failure is a leap too far. As to the glacier continuing to flow, and become another ice shelf, is inevitable and gravity powered. Provided precipitation continues up glacier the glacier/shelf system should continue. This is a long time frame process.
Mr R Gates, I can only say, and yet the world still cools regardless of your hot rhetoric. Perhaps a prayer to the ATON from the global warming brethren may do more for your cause than the anti science you espouse.
The global warming doom is fading with the release almost weekly of real science made possible by the release of a few rather damning emails a little while ago, thus they are being reported even in the MSM, such a shame for your cause that so much reality is coming forth.
I ask you to look at the solar influence and its rather easy to understand cycles, recent studies have shown a complete and accurate match to the temperature record, that correlates in hindsight and can be shown as the true driver of temperature and climate change. CO2 is irrelevant, all I ask is that you look at all evidence.
It’s blatantly obvious that the ice caps are losing mass, the vast majority of observational detail confirms that. It could be suggested that this has a correlation with Co2, but if so, why is the loss of ice not following a smooth curve and reflecting the increase in Co2? Currently ice loss has to an extent flattened off, though not recovered. It strikes me that basic concepts of cause and effect must indicate that other factors are at play.
R.Gates
It is kind of hard to express how to interpret the data from the sources that YOU posted, given that you seem to believe that Antarctica is rapidly losing ice at an accelerating rate. The Harvard link that you posted (the last one), says this in the summary (cut and pasted);
“Parts of the West Antarctic ice sheet and the Antarctic Peninsula are losing mass at an increasing rate, but other parts of West Antarctica and the East Antarctic ice sheet are gaining mass at an increasing rate.”
You realize that the East Antarctic ice sheet is where most of the ice is.