NASA study shows Antarctica's Larsen B ice shelf nearing its final act

May 15, 2015 by Steve Cole
Antarctica's Larsen B Ice Shelf is likely to shatter into hundreds of icebergs before the end of the decade, according to a new NASA study. Credit: NSIDC/Ted Scambos

A new NASA study finds the last remaining section of Antarctica's Larsen B Ice Shelf, which partially collapsed in 2002, is quickly weakening and likely to disintegrate completely before the end of the decade.

A team led by Ala Khazendar of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, found the remnant of the Larsen B Ice Shelf is flowing faster, becoming increasingly fragmented and developing large cracks. Two of its tributary glaciers also are flowing faster and thinning rapidly.

"These are warning signs that the remnant is disintegrating," Khazendar said. "Although it's fascinating scientifically to have a front-row seat to watch the ice shelf becoming unstable and breaking up, it's bad news for our planet. This ice shelf has existed for at least 10,000 years, and soon it will be gone."

Ice shelves are the gatekeepers for glaciers flowing from Antarctica toward the ocean. Without them, glacial ice enters the ocean faster and accelerates the pace of global sea level rise. This study, the first to look comprehensively at the health of the Larsen B remnant and the glaciers that flow into it, has been published online in the journal Earth and Planetary Science Letters.

Khazendar's team used data on ice surface elevations and bedrock depths from instrumented aircraft participating in NASA's Operation IceBridge, a multiyear airborne survey campaign that provides unprecedented documentation annually of Antarctica's glaciers, ice shelves and ice sheets. Data on flow speeds came from spaceborne synthetic aperture radars operating since 1997.

Khazendar noted his estimate of the remnant's remaining life span was based on the likely scenario that a huge, widening rift that has formed near the 's grounding line will eventually crack all the way across. The free-floating remnant will shatter into hundreds of icebergs that will drift away, and the glaciers will rev up for their unhindered move to the sea.

Located on the coast of the Antarctic Peninsula, the Larsen B remnant is about 625 square miles (1,600 square kilometers) in area and about 1,640 feet (500 meters) thick at its thickest point. Its three major tributary glaciers are fed by their own tributaries farther inland.

"What is really surprising about Larsen B is how quickly the changes are taking place," Khazendar said. "Change has been relentless."

The remnant's main tributary glaciers are named Leppard, Flask and Starbuck—the latter two after characters in the novel Moby Dick. The glaciers' thicknesses and flow speeds changed only slightly in the first couple of years following the 2002 collapse, leading researchers to assume they remained stable. The new study revealed, however, that Leppard and Flask glaciers have thinned by 65-72 feet (20-22 meters) and accelerated considerably in the intervening years. The fastest-moving part of Flask Glacier had accelerated 36 percent by 2012 to a flow speed of 2,300 feet (700 meters) a year—comparable to a car accelerating from 55 to 75 mph.

Flask's acceleration, while the remnant has been weakening, may be just a preview of what will happen when the remnant breaks up completely. After the 2002 Larsen B collapse, the glaciers behind the collapsed part of the shelf accelerated as much as eightfold – comparable to a car accelerating from 55 to 440 mph.

The third and smallest glacier, Starbuck, has changed little. Starbuck's channel is narrow compared with those of the other glaciers, and strongly anchored to the bedrock, which, according to authors of the study, explains its comparative stability.

"This study of the Antarctic Peninsula provides insights about how farther south, which hold much more land ice, will react to a warming climate," said JPL glaciologist Eric Rignot, a coauthor of the paper.

Explore further: New study shows Antarctic ice shelf is thinning from above and below

More information: The paper is online at: go.nasa.gov/1bbpfsC

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SamB
1.6 / 5 (12) May 15, 2015
Oh well. There will be another ice shelf in the future that the Church of Global Warming can bitch about...
Mike_Massen
3.9 / 5 (14) May 15, 2015
SamB being disingenuous and easily manipulated by propaganda stated
Oh well. There will be another ice shelf in the future that the Church of Global Warming can bitch about..
This is why a key education in Science is so important & especially so in Physics, so you become immune to politics, ranting from emotive groups with a commercial agenda etc

SamB please undersrand, CO2 has well known & irrefutably proven thermal properties of radiative forcing for >100yrs, it is known for trapping heat and this issue is settled Science

What isn't settled & subject to immense complexity is the competition for that heat re oceans, ice & atmosphere, add to that the immense capacity of water to absorb heat then you can appreciate that because of extra heat in the system there are consequences as to how that extra heat flows around to establish new equilibria ie. Push and something will shove, we have been seeing that for decades, loss of ice shelfs is consistent with that
SamB
1.4 / 5 (11) May 15, 2015
This is why a key education in Science is so important & especially so in Physics, so you become immune to politics, ranting from emotive groups with a commercial agenda etc


Yes, I agree that the Global Warming Church has become a ranting emotive group with a commercial agenda. At least we both agree on something!
Nullius in verba!

Mike_Massen
3.9 / 5 (14) May 15, 2015
SamB observed, perhaps partly incisive stated
Yes, I agree that the Global Warming Church has become a ranting emotive group with a commercial agenda. At least we both agree on something!
Nullius in verba!
Unfortunately your crafted reply suggest that you have been propagandized to by an major anti-AGW emotive crowd that's convinced itself AGW is only a political idea...

My case, long interest in electronics/physics & long history of uni qualifications back to 1982, so have strong formal background in essentials. AGW trend hasnt been foremost for me before 2008, so reviewed the physics & investigated essentials & came to the position

"Based upon Physics & Evidence re change in Earth's heat balance, primary cause of this additional heat is from human related activity, therefore Anthropogenic Global Warming & Climate Change is a valid proposition & especially so as Evidence continues to mount"

What's your specific position & evidence (substantive) if contrary ?
Returners
1.9 / 5 (14) May 15, 2015
I would just like to point out that the pacific has seen several earthquakes of 8.0 to 9.3 and the subsequent world-circling tsunamis that ensued afterwards during the time period mentioned, starting with the 2004 Boxing Day quake and Tsunamis, which broke up antarctic ice and shifted the Earth's axis by several inches. Surely you realize fracturing in the ice is more likely related to these quakes than to any CO2 effects in the atmosphere.
greenonions
4.4 / 5 (13) May 15, 2015
Surely you realize fracturing in the ice is more likely related to these quakes than to any CO2 effects in the atmosphere


Nope that thought never occured to me. Do you have any references that might support that hypothesis? You know - like maybe some research. Science by making stuff up does not generally work out too well.
Returners
1.7 / 5 (11) May 15, 2015
Surely you realize fracturing in the ice is more likely related to these quakes than to any CO2 effects in the atmosphere


Nope that thought never occured to me. Do you have any references that might support that hypothesis? You know - like maybe some research. Science by making stuff up does not generally work out too well.


Here dumbass:

https://www.youtu...uwMj7Xzo

Only the 100ft high waves the killed over 200k people.
Returners
1.7 / 5 (9) May 15, 2015
Water_Prophet
1 / 5 (8) May 15, 2015
Returners, that is a good observation. Earthquakes increase around developing reservoirs, dams, etc., stands to reason increasing sea and the inconceivable tons of extra water would induce analogous effects.

Just another reason that polar melting is the most important effect in climate change.
Water_Prophet
1 / 5 (8) May 15, 2015
Weren't these supposed to be growing, or did I miss an article?
greenonions
4.6 / 5 (10) May 16, 2015
Sorry there Returners - I did not see anything that could possibly link the break up of the Larsen Ice Shelf - to earth quakes around the world. Your article references 'tiny tremors', but gave NO reference to the collapse of the Larsen Ice Shelf. Again - science by making stuff up - does not usually work out well....
HeloMenelo
3.4 / 5 (10) May 16, 2015
Oh well. There will be another ice shelf in the future that the Church of Global Warming can bitch about...


There sure will be many more ice shelfs melting if we continue on the path we do now, that you got right little monkey, unfortunately it seems like however there won'tbe more more brain cells left to make you understand science.
HeloMenelo
3.3 / 5 (9) May 16, 2015
Weren't these supposed to be growing, or did I miss an article?

Nope you're not missing anything, accept brain matter, thanks for clarifying that to the world though ;)
Mike_Massen
3.5 / 5 (8) May 16, 2015
Water_Prophet claims
.. Earthquakes increase around developing reservoirs, dams, etc., stands to reason increasing sea and the inconceivable tons of extra water would induce analogous effects
Yet another claim, on a Science site, with ZERO backing, NIL rationalisation & STILL nothing to prove his most stupid claim that CO2's radiative forcing is a low 0.00009W/m^2 when accepted science shows its 1.5W/m^2

So what is so very wrong with Water_Prophet he can't do physics a "Physical Chemist" as he claims to be SHOULD be able to.

Water_Prophet caught out in LIE again (and again), & again ad-infinitum !

Water_Prophet claims
Just another reason that polar melting is the most important effect in climate change.
Really ? How did you arrive at that you obfuscator, compared how with ocean thermal movements, perturbation of the Atlantic thermohaline, La Nina, El nino etc etc etc

Water_Prophet PROVE your claims !

Retract your LIE re CO2, be smarter for a change
Mike_Massen
3.7 / 5 (9) May 16, 2015
Water_Prophet asked
Weren't these supposed to be growing, or did I miss an article?
According to what metric, what hypothesis, growing by mass or volume or including extent or what ?

Another indication Water_Prophet has lied about all his "4 technical degrees", he CANNOT handle details, Cannot apply Physics, Cannot understand radiative transfer, Cannot calculate thermal resistivity as someone who is schooled in "Physical Chemistry" (as he claims) SHOULD know or at least take 30mins to learn how to do it from first principles but, Water_Prophet can't even apply 30mins to prove his faked figure of 0.00009W/m^2 for CO2's radiative forcing ?

Water_Water_Prophet PROVE your claims or retract you were LYING all along ?

Prophet clearly not only missed articles he misses basic Physics education & Cannot be trusted !
Steve 200mph Cruiz
5 / 5 (8) May 16, 2015
Returners,
Earthquakes have been going on forever and we still have ice caps. However over millions of years, we've had falling Co 2 levels, there were no ice caps when dinosaurs roamed.
Robert_D
1 / 5 (7) May 17, 2015
"... it's bad news for our planet. This ice shelf has existed for at least 10,000 years, and soon it will be gone." So presumably the planet was in bad shape 10,000 years ago. This is the problem I have with climate alarmism. ALL news of climate change is reported as BAD news. Of course that is just ridiculous, some things will be better, and some worse. It will also hurt the public's view of science if the predictions are off and the consequences turn out to be mild. Yes, I agree the climate is changing, and it may require action, but the apocalyptic hype needs to stop.
gkam
3 / 5 (12) May 17, 2015
No, the news has to be spread, no matter those who do not "believe" the studies, or think they are excessively hyped. I leave that up to the professionals in that field, not commentators.
HeloMenelo
3.5 / 5 (8) May 17, 2015
nope not hype, it's science, and no something needs to be done NOW to prevent consequences that will happen Then and those that already started, of course the anti climate goriilas doesn't care about the earth they take on the attitude of monkeys, ie.. o well i'll just dump my garbage in the road.. not my problem..
gkam
2.6 / 5 (10) May 17, 2015
" o well i'll just dump my garbage in the road.. not my problem.."
----------------------------------

In this case, in the air and water, affecting life on Earth.
greenonions
5 / 5 (9) May 17, 2015
Rober_D - what in this article do you see as apocalyptic hype? Seems fairly factual to me. An ice sheet that has been here for 10,000 years - is now melting, and will soon be gone. Given that there are 7+ billion of us on the planet - and we all want to eat, sleep somewhere, and have energy to run our lives. What possible scenario could you see from sea level rise that could be "better?" (to use your word).
antigoracle
1 / 5 (5) May 17, 2015
leetennant
4.4 / 5 (7) May 17, 2015
Oh well. There will be another ice shelf in the future that the Church of Global Warming can bitch about...


That doesn't even make sense. Last I looked, the concern about the potential sea level rises from a melting Antarctic was pretty all-encompassing. Land ice melt bad. So, yeah, we're going to "bitch" about it melting pretty consistently.

Weren't these supposed to be growing, or did I miss an article?


The day people work out the difference between land and sea ice will be as great a day as the day people work out the meaning of the terms "global" and "average". It's the land ice melt and global warming that's *causing* the increase in sea ice extent. It's actually really interesting if you ever bothered doing some research into it.
HeloMenelo
2 / 5 (4) May 18, 2015
Good to see the monkeys hitting record lows on the iq and rating scale.. keep 'em coming my monkeys, remember the record is 200 dumb posts, still a long way to go so get crackin... we're waiting...

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