From the European Space Agency (ESA):
Satellite observes rapid ice shelf disintegration in Antarctic
5 April 2012
As ESA’s Envisat satellite marks ten years in orbit, it continues to observe the rapid retreat of one of Antarctica’s ice shelves due to climate warming.
One of the satellite’s first observations following its launch on 1 March 2002 was of break-up of a main section of the Larsen B ice shelf in Antarctica – when 3200 sq km of ice disintegrated within a few days due to mechanical instabilities of the ice masses triggered by climate warming.
Now, with ten years of observations using its Advanced Synthetic Aperture Radar (ASAR), Envisat has mapped an additional loss in Larsen B’s area of 1790 sq km over the past decade.
The Larsen Ice Shelf is a series of three shelves – A (the smallest), B and C (the largest) – that extend from north to south along the eastern side of the Antarctic Peninsula.
Larsen A disintegrated in January 1995. Larsen C so far has been stable in area, but satellite observations have shown thinning and an increasing duration of melt events in summer.
“Ice shelves are sensitive to atmospheric warming and to changes in ocean currents and temperatures,” said Prof. Helmut Rott from the University of Innsbruck.
“The northern Antarctic Peninsula has been subject to atmospheric warming of about 2.5°C over the last 50 years – a much stronger warming trend than on global average, causing retreat and disintegration of ice shelves.”
Larsen B decreased in area from 11512 sq km in early January 1995 to 6664 sq km in February 2002 due to several calving events. The disintegration in March 2002 left behind only 3463 sq km. Today, Envisat shows that only 1670 sq km remain.
Envisat has already doubled its planned lifetime, but is scheduled to continue observations of Earth’s ice caps, land, oceans and atmosphere for at least another two years.
This ensures the continuity of crucial Earth-observation data until the next generation of satellites – the Sentinels – begin operations in 2013.
Credits: ESA
“Long-term systematic observations are of particular importance for understanding and modelling cryospheric processes in order to advance the predictive capabilities on the response of snow and ice to climate change,” said Prof. Rott.
“Climate models are predicting drastic warming for high latitudes. The Envisat observations of the Larsen Ice Shelf confirm the vulnerability of ice shelves to climatic warming and demonstrate the importance of ice shelves for the stability of glaciers upstream.
“These observations are very relevant for estimating the future behaviour of the much larger ice masses of West Antarctica if warming spreads further south.”
Radars on Earth observation satellites, such as Envisat’s ASAR, are particularly useful for monitoring polar regions because they can acquire images through clouds and darkness.
The Sentinel missions – being developed as part of Europe’s Global Monitoring for Environment and Security (GMES) programme – will continue the legacy of radar observations.
To continue from my post above, from
http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt
while the global trend is +0.13/decade since UAH went into operation in 1978, the trend in the Antarctic is a cooling at -0.05/decade if I am interpreting it right.
But how does this agree with (or am I missing something):
CD (@CD153) says:
April 5, 2012 at 3:51 pm
“The northern Antarctic Peninsula has been subject to atmospheric warming of about 2.5°C over the last 50 years – a much stronger warming trend than on global average, causing retreat and disintegration of ice shelves.”
Am I to believe the whole Antarctic is cooling for decades but one little bit is warming? If that is indeed the case, I cannot believe that CO2 is the reason. As stated elsewhere, perhaps volcanoes are the reason.
I’ll bet the break up in 2002 generated a multitude of stories like “We only have 10 years to…….
save Antarctica, save the glaciers, stop a 20 meter sea level rise or oh hell to save earth from evil mankind. But now all they have to report is their worst sea ice pic from orbit on their 10th anniversary. What a bunch of cherry picking cry babies……………..
Uzi
Wot a load of old Rott!
There ought to be some extraordinary fossils there in those exposed areas. I wouldn’t last two minutes in -52C air though.
There seems to be confusion here between annual Arctic sea ice and Antarctic ice shelves. Annual ice may be one to a few meters thick. Shelves are much thicker; some are a kilometer thick. Comparing the area of annual ice with the area of shelves doesn’t make a lot of sense. The ESA article is about an ice shelf.
There is one rather large problem with the ‘global warming caused this’ explanation, which is that there has been a large increase in sea ice in this area. We are about a month past Antarctic sea ice minimum, and the Larson iceshelf is surrounded by sea ice that extends by an average of about 200 kilometers beyond the long term (30 year) average extent.
If global warming is melting the Antarctic Peninsula icesheets, why is the sea ice adjacent to the Peninsula increasing at such a rapid rate?
http://nsidc.org/data/seaice_index/images/daily_images/S_bm_extent_hires.png
BTW, the answer is probably, the Larsen icesheet is responding to past warming. How long ago is anyone’s guess. Another possible explanation is an increase in upwelling of relatively warm water along the edge of Peninsula.
Hugh Pepper says:
April 5, 2012 at 3:52 pm
What we see occurring at both Poles and in the Himalayas are changes equivalent to the “canary in the cage” phenomena. A very real danger is that the muskeg in the North will also melt releasing vast quantities of methane and CO2. Should this occur warming will accelerate even more rapidly than at present.
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LOL, lets do a little math. So a little area of warming, 1,700 sq K, of ice may be breaking off or reducing, due to ocean current changes, maybe due to underwater volacanism, is overwhelmed by 500,000 sq K of additionals sea ice, panic, the oeans are boiling.
Smokey (April 5, 2012 at 6:00 pm):
Thanks for taking the time to reply. Though the IPCC climate models are popularly taken to make forecasts, they make none of them. They make “projections” which, though often taken to be forecasts, are not
How many tugboats would it take to nudge that big ice wafer to port for some country in need of fresh water!?
I found this image interesting.
http://en.wikipedia.org/wiki/File:AntarcticBedrock.jpg
If the color coding is to believed, a lot if Antarctica is below sea level and subject to ocean forces.
This will give an indication of elevation and flow rates are found here, scroll down 2/3 the page.
Ice, like unreinforced concrete has low tensile strength and is assumed to have none when it is cracked. No engineer would build an unreinforced suspended or cantilevered slab as it would crack and collapse easily. The greater the span or projection, the more likely the failure.
More ice formation makes the ice shelf larger and heavier and more likely to crack and break off. Melting or less freezing would make the shelf lighter and smaller and less likely to break.
What is needed is properly engineered reinforcement installed in the top of the ice shelf. The steel and pipeline industries could carry out this task. Immediate action is required as concerned scientific consensus has determined that Antarctic ice shelf cracking is greatest threat to life on this planet. We cannot leave our children with a planet of cracking ice shelves.
Golly gee whiz… I sure wonder how this world got to where it is. So much hysteria over something that useless.
Maybe some recent tsunami activity had some affect on the crack.
Where is all that Crackspackle when you need it?
Terry Oldberg says:
April 5, 2012 at 8:51 pm
Though the IPCC climate models are popularly taken to make forecasts, they make none of them. They make “projections” which, though often taken to be forecasts, are not
=======================================
Really? According to the WordWeb dictionary the first meaning of the word “projection” is (surprise!): “a prediction made by extrapolating from past observations”.
And of course those projections have always been sold to the press and politicians by “climate scientists” as predictions.
Greg House ( April 5, 2012 at 10:19 pm ):
Thanks for giving me the opportunity to clarify. As you point out, at least one dictionary uses the two word as synonyms. However, as the two words reference distinct ideas in the climatological literature, to use them as synonyms in this context is to conflate these ideas.
To conflate them causes trouble, for while a model’s “predictions” are falsifiable, a model’s “projections” are not falsifiable. Thus, to conflate the two ideas confuses entities that are not falsifiable with entities that are. A consequence is for it to appear that the methodology by which the IPCC reached its conclusion of CAGW from CO2 emissions was scientific when it was not.
In an article published a year ago at http://judithcurry.com/2011/02/15/the-principles-of-reasoning-part-iii-logic-and-climatology/ I covered this topic in depth . However, bloggers in wattsupwiththat continue to conflate the two ideas by treating “prediction” and “projection” as synonyms. In doing so, they make themselves dupes of the IPCC. For the future, if bloggers were to take it upon themselves to avoid this practice, it would be clearly seen that the IPCC’s conclusions are not a conclusion from a scientific study and should be disregarded for this reason.
@Joseph Bastardi Looks like a steady increasing trend IMO. Thanks for the link.
It may be worth noting that the Larsen B iceshelf is 2,750km from the South Pole. Transpose that to the northern hemisphere and that places it fair square in the middle of Alaska and Iceland, Southern Greenland and well inside Canada, Norway, Russia, Finland and Sweden or in the Bering Sea, take your pick.
RE
Steven Mosher says:
@ur momisugly April 5, 2012 at 8:01 pm
“…Finally, c02 doesnt “cause” warming in the way you think. Adding C02 or any GHG to the atmosphere raising the height at which the earth radiates that means, following known physical law, that the earth will cool less rapidly than it would otherwise. The spatio temporal distribution of that effect is not homogenous. We expect differentials.”
…………………………..
Oh right. And do the “differentials” also explain how it is that, during past ice ages of the most recent 2MY, global temperatures appear to decline while atmospheric [CO2] lags by as much as 3000 years?
It’s the question the AGW believers and warmists generally never seem to want to answer – or offer an explanation. In the fatansy of virtual reality of “runaway greenhouse” how is it that global temperatures ever manage to do a U-turn at all with declines in CO2 lagging by several hundered-several thousand years?
Is it because the maximum amount of CO2 is already in the atmosphere providing a cieling to maximum warming?
Or do we get to find out in the next installment of ‘Nature: Other-worldly tricks and the temperature-CO2 (de-)coupled hypothesis (minus error bars)’?
Gail Combs, here is a UGS world earthquake map for 2002, I too suspected a possible tsunami or seismic event, when you look at the map you will notice that Antarctica appears to be the only country/continent on the planet with out an earthquake, ever ?
Although, many earthquakes are registered in the nearby oceans.
Here is a KML for google earth that will show you all Mag5 earthquakes.
2002 Earthquakes, Magnitude 5 ( http://www.google.com/url?q=http://earthquake.usgs.gov/earthquakes/eqarchives/epic/kml/2002_Earthquakes_Mag5.kmz&sa=U&ei=jJp-T7yZIcX4mAXW5830Bw&ved=0CBMQFjAH&client=internal-uds-cse&usg=AFQjCNGrvlIJf7qzaHah_GkUX5atT4UoLg )
The link came from this page ( http://earthquake.usgs.gov/search/?q=pacfic+ocean+2002&x=0&y=0&cx=012856435542074762574%3A49ga9ubtojk&cof=FORID%3A11&sa=Search )
Should this article not be acompanied by a picture of a forlorn looking penguin standing on an isolated ice flow, (having forgotten how to swim and fish, obviously). With a little more Rott from Doctor Rott telling us how the poor little thing will starve without the ice?
Ice shelves break mechanically not by melting.
By the way, has anybody seen AlGore and the Hansen/Branson since they went to the Antarctic? I have seen nothing about their triumphal return in the media, just a letter from the Hansen to Slovenia which could have been written by any 12 year old greenie activist. Are they still there, crow-barring bits off the ice shelf? Should we send a search party?
sorry, I forgot to add the earthquake map link
http://earthquake.usgs.gov/earthquakes/eqarchives/year/2002/2002_data.php
Greg House says:
April 5, 2012 at 10:19 pm
“Terry Oldberg says:
April 5, 2012 at 8:51 pm
Though the IPCC climate models are popularly taken to make forecasts, they make none of them. They make “projections” which, though often taken to be forecasts, are not
=======================================
Really? According to the WordWeb dictionary the first meaning of the word “projection” is (surprise!): “a prediction made by extrapolating from past observations”.
And of course those projections have always been sold to the press and politicians by “climate scientists” as “predictions.”
The IPCC is careful enough to include a section where they define what is a projection and what’s a prediction in their book, so you can’t blame them for using words as they define them. Sorry no link, it’s somewhere in the AR4.
Anyhow, their idea is that they can’t make a prediction because they can’t initialize a climate model with the exact state at a given time as that state is not known. But that’s just a thinly veiled disguise to escape the critizism of mathematically knowledgeable nitpickers who tend to say, you can’t make a prediction for 2100 because of the exponentially growing discrepancy between your model and reality. This criticism cannot be refuted, only evaded.
So it’s all a semantic game by the IPCC to evade criticism. BTW, assuming that what the IPCC does is scientific, they should have discussed these arguments themselves. But they have no competent personnel – watch Donna about that:
http://notrickszone.com/2012/04/05/eike-releases-4th-climate-conference-videos-of-speakers/
LazyTeenager says: April 5, 2012 at 7:17 pm “I am not a climate scientist either so allow me to speculate. Most of the earth’s increased heat retention occurs at the equator and the excess heat then moves to the poles. So heat collected over a large area is concentated into a smaller area. Hence a moderate temp increase at the equator becomes a larger one at the poles.”
No, you should not be allowed to speculate when you write absolute drivel that has nought to do with the long, proud heritage of established physics. There have neen some home-made explanations of science on blogs before, but this is the doozy. Completely nuts.
Finally, c02 doesnt “cause” warming in the way you think. Adding C02 or any GHG to the atmosphere raising the height at which the earth radiates
So Steven, presumably you have the mathematics to be able calculate this change in height. Should come from the model you are using. Good, please inform us idiots of the change in height for an increase in co² of 3.27% of 0.00039 ppm (the human contribution) or for the total non-uniform addition to the atmosphere of about 100ppm.
Its just a normal cycle, snow falls, glaciers form, glaciers move towards the sea, ice shelf forms, ice shelf gets pushed out to sea, ice calves, bergs break off, bergs melt, snow falls, glaciers form, glaciers move towards the sea, ice shelf forms, ice shelf gets pushed out to sea, ice calves, bergs break off, bergs melt, etc etc etc.
Snake oil salesman – as if warming would cause ice to break, does an ice block ‘ break’ as it warms ?
Of course not, it melts from outside to in.
These AGW obsessed fools see all things as anthrocentric.
RE
Disko Troop says:
@ur momisugly April 6, 2012 at 12:41 am
I didn’t know Al and Jimbo were there…perhaps the title of this thread have been: ‘More Crap in the Anatarctic’?