A deep crack on on Antarctica's Larsen C ice shelf has nearly severed off one of the largest icebergs ever recorded:
One of the largest icebergs ever recorded — 2,500 square miles, about the size of Delaware — is about to break off Antarctica, according to the European Space Agency. The iceberg could speed up the break-off of other ice chunks, eventually eating away at a barrier that prevents ice from flowing to the sea.
The impending iceberg is being carved from one of the continent's major ice shelves, called Larsen C. Scientists have been monitoring Larsen C for months now, as a deep crack has slowly extended over the course of 120 miles. Only about three miles of ice are keeping the iceberg attached to the shelf, ESA says. No one knows when it will break off — it could be any moment — but when it does, the iceberg will likely be 620 feet thick (about the height of the Waldorf Astoria hotel in New York) and contain roughly 1 trillion tons of ice. It'll be drifting north toward South America, and could even reach the Falkland Islands. "If so it could pose a hazard for ships in Drake Passage," Anna Hogg from the University of Leeds, said in a statement.
Also at BBC.
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A one trillion tonne iceberg – one of the biggest ever recorded - has calved away from the Larsen C Ice Shelf in Antarctica. The calving occurred sometime between Monday 10th July and Wednesday 12th July 2017, when a 5,800 square km section of Larsen C finally broke away. The iceberg, which is likely to be named A68, weighs more than a trillion tonnes. Its volume is twice that of Lake Erie, one of the Great Lakes.
http://www.projectmidas.org/blog/calving/
Also at BBC, PBS, The Guardian, and The Verge.
Complete Calving Coverage:
Antarctic Larsen C Ice Shelf to Calve; Halley VI Research Station Plans Move
Antarctic Ice Rift Close to Calving, After Growing 17km in 6 Days
Delaware-Sized Iceberg Could Break Off of Antarctica at Any Moment
Larsen C Rift Branches as it Comes Within 5 km of Calving
It's finally adrift. When the Larsen C Ice Shelf calved yesterday [Wednesday], it sent one of the largest icebergs ever recorded slipping into a sea frosted with smaller chunks of ice. It marked the end of a decades-long splintering first seen by satellites in the 1960s. The crack stayed small for years until, in 2014, it began racing across the Antarctic ice.
The massive iceberg holds twice as much water used in the United States every year, according to calculations by Peter Gleick of the Pacific Institute. It weighs about 1.1 trillion tons and measures 2,200 square miles. Its volume is twice that of Lake Erie.
"The iceberg is one of the largest recorded, and its future progress is difficult to predict," said Adrian Luckman of Wales' Swansea University, who led a project tracking the crack since 2015. "It may remain in one piece but is more likely to break into fragments. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters."
By mass, the iceberg accounts for 12 percent of the Larsen C Ice Shelf. It's large enough that maps will have to be redrawn. Larsen C was the fourth-largest ice shelf in the world. Now it's the fifth.
In this particular political moment, the calving of a major iceberg has made headlines around the world. Environmental groups connected the event to climate change and the Trump administration's withdrawal from the Paris climate accords. But scientists have cautioned that the story of the iceberg, which will be known as A68, is more nuanced. Climate signals are not clear enough to attribute the event to rising levels of carbon dioxide, but human activity may have contributed to its calving nonetheless.
https://www.eenews.net/stories/1060057298
Previously:
Larsen C Calves Trillion Ton Iceberg
Larsen C Rift Branches as it Comes Within 5 km of Calving
Delaware-Sized Iceberg Could Break Off of Antarctica at Any Moment
Antarctica 'gives ground to the ocean'
Scientists now have their best view yet of where Antarctica is giving up ground to the ocean as some of its biggest glaciers are eaten away from below by warm water.
Researchers using Europe's Cryosat radar spacecraft have traced the movement of grounding lines around the continent. These are the places where the fronts of glaciers that flow from the land into the ocean start to lift and float. The new study reveals an area of seafloor the size of Greater London that was previously in contact with ice is now free of it.
[...] On the face of it, the results are pretty much as expected. Of the 1,463km² of grounded ice that has been given up, most of it is in well documented areas of West Antarctica where warm ocean water is known to be infiltrating the undersides of glaciers to melt them.
Dr Konrad explained: "If you take 25m per year as a threshold, which is sort of the average since the end of the last ice age, and you say anything below this threshold is normal behaviour and anything above it is faster than normal - then in West Antarctica, almost 22% of grounding lines are retreating more rapidly than 25m/yr. "That's a statement we can only make now because we have this wider context."
The new data-set confirms other observations that show the mighty Pine Island Glacier, one of the biggest and fast-flowing glaciers on Earth, and whose grounding line has been in retreat since the 1940s, appears now to have stabilised somewhat.
Net retreat of Antarctic glacier grounding lines (DOI: 10.1038/s41561-018-0082-z) (DX)
Related: Delaware-Sized Iceberg Could Break Off of Antarctica at Any Moment
Secrets of Hidden Ice Canyons Revealed
(Score: 0) by Anonymous Coward on Thursday July 06 2017, @10:24AM
I hope you have that Titanic at hand, will yea?
(Score: 4, Informative) by kaszz on Thursday July 06 2017, @10:32AM (23 children)
Volume of water added: 1 trillion tons of ice = 1e12 m³ (approximately)
Total surface [hypertextbook.com] area of Earth seas: 3.618e14 m²
Added sea height from this ice block: 1e12 / (361800000*1000^2) = 0.002764 meters = 2.8 mm
How it affects Gulf Stream etc is another matter.
(Score: 2, Informative) by Anonymous Coward on Thursday July 06 2017, @10:35AM (2 children)
This ice is already in the water though?
(Score: 2) by bob_super on Thursday July 06 2017, @06:16PM (1 child)
A good part of it was on land until fairly recently.
(Score: 0) by Anonymous Coward on Thursday July 06 2017, @09:19PM
I honestly don't know, but we seem to have a constant stream of articles about this so you would think we would know if these articles were worth anything.
(Score: 1) by shrewdsheep on Thursday July 06 2017, @10:40AM (3 children)
The biggest factor in rising sea levels (at this moment) is thermal expansion. Potentially, this ice could lower sea temperatures, causing thermal shrinkage. Doing the exact calculations is left as an exercise.
(Score: 2) by acid andy on Thursday July 06 2017, @11:00AM (2 children)
Surely the cooling effect of that block of ice would only be very temporary whereas the greenhouse effect (probably responsible for that ice melting to begin with) is much more prolonged so the net result over the longer term is still increased thermal expansion. Is that why you qualified your statement with "at this moment"?
Of course the warmer air that is melting the ice will warm up the surface of the sea slightly at the same time as well.
If a cat has kittens, does a rat have rittens, a bat bittens and a mat mittens?
(Score: 2) by TheRaven on Friday July 07 2017, @09:26AM (1 child)
sudo mod me up
(Score: 0) by Anonymous Coward on Friday July 07 2017, @10:30AM
This will decrease the albedo of the surface and increase it's heat capacity, but that isn't what the greenhouse effect refers to.
(Score: -1, Troll) by Anonymous Coward on Thursday July 06 2017, @10:55AM (2 children)
The volume of this over-hyped ice cube is already .62% displaced. Further, since the water it is dissolving into is nearly the same temperature as the ice, the thermal delta coefficient is infinitesimally small.
A few cloudy days over the vast sea region causes more than enough radiated surface cooling to render the net effects insignificant.
#hype #junkscience #clickbait
(Score: 2) by acid andy on Thursday July 06 2017, @11:02AM
That doesn't matter. The point is that over time, on average, they are both getting warmer.
If a cat has kittens, does a rat have rittens, a bat bittens and a mat mittens?
(Score: 0) by Anonymous Coward on Thursday July 06 2017, @02:56PM
0.62%? As in 0.0062 of the total?
(Score: 3, Informative) by c0lo on Thursday July 06 2017, @11:34AM (6 children)
No added sea height, it's an iceberg. It it already floating and Archimedes eureka-ed it's dislocating a volume of water equal in weight with its own.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by kaszz on Thursday July 06 2017, @11:58AM (5 children)
It was not an iceberg when it was attached to the rest of the ice continent. And when it melts enough to let the top slip down below the water level the sea level will increase additionally too.
(Score: 1, Informative) by Anonymous Coward on Thursday July 06 2017, @12:35PM (3 children)
The volume shrinks when ice melts. You are clueless.
(Score: 2) by kaszz on Thursday July 06 2017, @02:05PM (2 children)
Sure, but will it shrink enough to matter in relation to other factors?
(Score: 3, Informative) by MrGuy on Thursday July 06 2017, @04:49PM (1 child)
It will shrink exactly to occupy the volume it currently displaces.
A floating object displaces exactly enough water to exactly balance the object's weight. i.e. an object floats at a height where the volume of the submerged portion would, if completely filled with water, have the same weight as the whole floating object.
The "trick" here is that the weight of the water IN THE ICEBERG doesn't change when it melts. If you measured the weight of the iceberg before it melted, and measured the resulting water after it melted, they'd weigh the same. Which means that the pre-melted iceberg and the post-melted iceberg displace the exact same amount of water. So the melting of the iceberg won't affect the sea level any.
Now, if the iceberg shelf was NOT currently floating (e.g. it was a kind of ice bridge over the ocean that was sitting ABOVE where it would "naturally float"), then you'd be correct that the calving off of the iceberg WOULD raise sea levels when the iceberg entered the water for the first time. My understanding is that's not how the antarctic ice shelves work (which makes sense - a 125-mile long chunk of ice being held higher than gravity would tell it to my a 3-mile frozen section would be fighting TREMENDOUS leverage at the narrow attachment point, and would certainly have broken off by now).
(Note for nitpickers - Yes, I'm ignoring some factors that technically come into play here, for example of the salinity of the iceberg and the salinity of the water it floats in aren't equal, the difference in density WOULD have an impact. Also, as the water warms post-melting, it actually shrinks slightly (up to 4 degrees C), then starts expanding. Those are things that can be factored in once we're clear on the general principals.)
(Score: 2) by c0lo on Thursday July 06 2017, @06:10PM
(imagination running amok,'ey?)
How about a piece of ice sustained by the sea bottom all the size? Like sea frozen there, then snow piling on top until the weight is too much to allow the ice to float?
In the extreme case, make the initial sea depth being zero and have only snow piling on top and compacting as ice?
Sounds familiar? Those are glaciers. When they melt, the sea level rises. Like the Greenland icesheet meltdown [sciencemag.org]
(yes, one can imagine glaciers that are actually advancing in the sea without calving icebergs - too thick to start with when pushed by the ice sheet behind. Or just surface melting until lightweight to stat floating. In both cases, the sea level will grow because of the water displaced or the result of melting)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Informative) by c0lo on Thursday July 06 2017, @01:03PM
Do you know why is called a "shelf"? Because it's floating, even when attached to the land mass.
Don't confuse it with glaciers - true, glaciers give birth to ice shelves, but Larsen C was floating since a long time ago; the imminent calving won't change the sea level.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by aclarke on Thursday July 06 2017, @01:48PM (4 children)
Thank you. I saw "size of Delaware" and thought WTF. Then I saw 2,500 sq.mi and thought WTWTF.
None of that explains to me how many American football fields that is. The answer is 58,000 American football fields for anyone who is confused by all these other meaningless measurements.
(Score: 3, Interesting) by kaszz on Thursday July 06 2017, @02:19PM (3 children)
Whenever I see measurements like "American football field" it kind of implies the author is generally not worth any attention span or time. Its very origin implies people that spend more time on football than science and as such know less than those that do spend their attention on science.
The practical aspect is that every football field is slightly different and the measurement is very bigoted against people that don't involve themselves with that as they will not have a real life experience sufficiently internalized to matter. And measurements like square meter may be hard to grasp in the beginning but with time a person will get reference points and so can make sense of the abstract number. At this stage with the benefit that the measurement unit learned is consistent across nations and subjects.
(Score: 2) by FatPhil on Thursday July 06 2017, @03:09PM (1 child)
So, karma-whoring, let's call this school of icebergs (as it will whelp) nearly a third the area of Wales, and more than a fifth the area of Belgium.
South Americans - you're on you're own. Shall we call it an East Falkland, and if you can't relate to that, then don't even think of invading it!
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by darnkitten on Friday July 07 2017, @12:28AM
Converting into recognized scientific measurements---
Slightly more than .3 Waleses or .2 Belgiums, and slightly smaller than the East Falklands.
Based on Kaszz's calculations and a bit of internet searching, the meltwater would fill about 400 million Olympic sized swimming pools, the unmelted ice around 430 million.
Unfortunately, I was unable to determine how many Libraries of Congress could be filled, as I was able to find the number of volumes held by the LofC, but not the spatial volumes of the buildings themselves, nor even the average volume of the books therein.
(Score: 2) by aclarke on Thursday July 06 2017, @03:15PM
I modded your comment as informative, then decided to respond with a genuine thank-you. The football fields comment was meant as a joke.
(Score: 2) by MrGuy on Thursday July 06 2017, @04:35PM
Someone's got to translate that into fractions of the Empire State Buildings for me, which is the preferred standard New York City building of measure.
You can't tell me something is about "twice as tall as the building on the southeast corner of 47th and broadway" and expect it to mean something to me. We need standards here, people!
(Score: 0) by Anonymous Coward on Thursday July 06 2017, @10:33AM (8 children)
If this doesn't happen what will people think of the news' reputation? Or maybe most people thing each story is about a new iceberg?
(Score: -1, Troll) by Anonymous Coward on Thursday July 06 2017, @10:57AM (5 children)
Anything to feed the AGW money machine.
(Score: 4, Insightful) by GreatAuntAnesthesia on Thursday July 06 2017, @02:22PM (4 children)
Yeah, those darned AGW types with their endless stream of cash from wealthy hippies and billionaire whales to push their selfish, self-enriching agenda. I mean when was the last time you saw a climate scientist driving round in anything less than a Maserati?
Meanwhile the poor defenceless oil companies have no means at all to fight back. Every time they need a little bit of money just to build an oil rig or topple a middle eastern regime, they have to hold a raffle outside the local primary school, with the first prize being a lovely sponge cake baked by Mrs Koch.
(Score: 1) by fustakrakich on Thursday July 06 2017, @06:29PM
when was the last time you saw a climate scientist driving round in anything less than a Maserati?
:-) When was the last time you saw a climate scientist walking to Paris?
La politica e i criminali sono la stessa cosa..
(Score: 0, Troll) by khallow on Thursday July 06 2017, @08:57PM
(Score: 0) by Anonymous Coward on Thursday July 06 2017, @09:23PM
There was this couple who tried to get "climate deniers" investigated under RICO laws but then it was quickly found they had been embezzling grant money:
http://dailysignal.com/2016/03/23/science-agency-eyes-climate-change-professors-use-of-millions-from-taxpayers/ [dailysignal.com]
Not sure what happened with that one.
(Score: 0) by Anonymous Coward on Friday July 07 2017, @12:17AM
Those climate scientists are like astrologers with an Excel spreadsheet. Everyone wants to get paid.
(Score: 2) by c0lo on Thursday July 06 2017, @11:37AM
You know, we are in the middle of Antarctic winter, and that block continue to split from the rest.
Wanna bet it's going to separate sometime in the next 6 months?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by Joe Desertrat on Thursday July 06 2017, @10:27PM
It will happen eventually. The reason it keeps popping up as an imminent catastrophe story is the sorry state of science reporting, although I suppose we should be happy it gets mentioned at all in a corporate controlled media world. The crack is continually lengthening, but of course such things do not happen at a steady rate. At some point, probably within 1-3 years, it will break off. Then the next crack will get the same press treatment.
(Score: 3, Interesting) by VLM on Thursday July 06 2017, @11:32AM (1 child)
It could make it all the way to the St Lawrence seaway and block Lake Huron which is only 183 miles at its fattest. There's a lot of "it could" out there.
It should be possible to take a big berg like that, trap it in a bay somewhere, and melt it for fresh water. Eventually via sewage or evaporation it would all end up in the ocean, but meanwhile it could be quite handy to have all that water.
(Score: 2) by bob_super on Thursday July 06 2017, @06:25PM
The UAE wanted to send tugs, but they're too busy having an argument with Qatar.
Hollywood is sending a couple heavy lift helicopters instead. Using movie physics, they were planning a non-stop return flight with the whole thing, but some producer decided to make a stop in Jamaica to get a good sunset shot.
(Score: 2) by martyb on Thursday July 06 2017, @01:09PM
Found an older story on phys.org, Video: Larsen-C ice shelf crack [phys.org] (from 2017-04-21).
It includes a video [internapcdn.net] showing the progress of the crack across the Larsen C ice shelf. Also shows how interferometry of radar images is used to better 'see' how far the crack has progressed.
Also, there is another story on phys.org, Giant iceberg in the making [phys.org] (posted 2017-07-05) which provides a summary, in metric units, of what is happening:
There is an animated gif [internapcdn.net] of the predicted shape of the forthcoming iceberg, too.
Wit is intellect, dancing.
(Score: 2) by BK on Thursday July 06 2017, @01:18PM (1 child)
It seems to me that we could leave this article pinned to the front page basically forever. Am I missing something?
...but you HAVE heard of me.
(Score: 2) by realDonaldTrump on Thursday July 06 2017, @01:44PM
This thing has been in the news since 2015. Before I started my campaign. Folks, it's ice. It slides into the ocean, breaks off, floats around and melts. That's what it does. What it's doing isn't news. If it did something different, that would be news. But it's just doing its thing. It's just being ice. And it gets a lot, a lot of attention. The #MSM won't shut up about it. And here I am, trying to do important things. To make America great again. But the #MSM ignores me. Larsen C gets all the attention. Just melt already! I can't wait till it melts. Till we have a beautiful series of islands. I have it on good authority that Antarctica will be a series of islands. Perfect for a resort like Trump National Le Chateau des Palmiers. It's gonna be great. youtu.be/aMAxgNz5cxY 🇺🇸
(Score: 0) by Anonymous Coward on Thursday July 06 2017, @01:36PM (3 children)
I can see this being a thing. Setup temp housing on the Burg when it detaches. 3-6 months later you're in the Falklands. Not many people get to ride a glacier cruise.
(Score: 2) by Sulla on Thursday July 06 2017, @02:56PM (1 child)
Three months is a long time to go without the benefits of the modern world. Could probably get around that problem by strapping some diesel generators on top to power the temporary structures.
Ceterum censeo Sinae esse delendam
(Score: 2) by takyon on Thursday July 06 2017, @05:39PM
Seems like it would be easy to construct an air strip on it. Direct flights to the iceberg!
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Thursday July 06 2017, @04:38PM
No bikinis for Ginger and Mary Ann! :(
(Score: 2) by AnonTechie on Thursday July 06 2017, @03:25PM
I believe UAE wanted to bring icebergs from Antartica. This is a great opportunity for them ...
https://www.independent.co.uk/news/world/middle-east/uae-icebergs-drinking-water-from-antarctica-towed-united-arab-emirates-a7715561.html [independent.co.uk]
Albert Einstein - "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
(Score: 0) by Anonymous Coward on Friday July 07 2017, @12:22AM
How about gluing it back together? Some fresh water and cooling coils would do the trick.