Larsen C Ice Shelf: Crack Has Less Than 20 Kilometers To Go Before Calving

[hatrack]

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An iceberg expected to be one of the 10 largest ever recorded is ready to break away from Antarctica, scientists say. A long-running rift in the Larsen C ice shelf grew suddenly in December and now just 20km of ice is keeping the 5,000 sq km piece from floating away.

Larsen C is the most northern major ice shelf in Antarctica. Researchers based in Swansea say the loss of a piece a quarter of the size of Wales will leave the whole shelf vulnerable to future break-up. Larsen C is about 350m thick and floats on the seas at the edge of West Antarctica, holding back the flow of glaciers that feed into it.

Researchers have been tracking the rift in Larsen C for many years, watching it with some trepidation after the collapse of Larsen A ice shelf in 1995 and the sudden break-up of the Larsen B shelf in 2002.

Last year, researchers from the UK's Project Midas reported that the Larsen C rift was growing fast. But in December the speed of the rift went into overdrive, growing by a further 18km in just a couple of weeks. What will become a massive iceberg now hangs on to the shelf by a thread just 20km long.

EDIT

http://www.bbc.com/news/science-environment-38522954

[lapfog_1]

1. Can we at least tow it someplace, stick some

big ass pipes and water pumps on the surface, collect the melt water and use it to fill the California Aqueduct or something?

A few billion dollars for probably 100 billion gallons of fresh water for central valley farmers plus Los Angeles.

Of course, the vast majority of the ice would simply melt into the Pacific and might cause harm to the local salinity of the ocean... but hey, it's the trumpocalypse so we might as well grow some food until the planet dies.

[hatrack]

2. Even if you could get it there w/o melting, It would run aground well offshore, alas!

If the Ross Shelf, for example, shows 200 feet (give or take) above the water at its edge, there's lots more below the water line.

The Ross varies from 1,300 to 2,300 thick, depending on where you are. Of course, the thickest parts are well south, and well away from the ocean, since the whole shelf is about the size of France.

[OKIsItJustMe]

10. The Many Failures and Few Successes of Zany Iceberg Towing Schemes

https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/

[font face=Serif][font size=5]The Many Failures and Few Successes of Zany Iceberg Towing Schemes[/font]

Alexis C. Madrigal | Aug 10, 2011

[font size=3]Every few years for the past couple centuries, even before the large-scale cultivation of marijuana, this idea occurs to someone: What if we towed an iceberg from the poles, where there are no people, to some dry, populous place and then melted it into freshwater?

In some cases, that person has ginned up a company to try to make it happen. In others, they've written reports for the RAND Corporation or turned the idea into the basis for a thriller mass market paperback.

Long-distance iceberg towing is one of those ideas that will not die but never really springs to life either. It exists in a kind of technological purgatory, dressed up in whatever technology is fashionable during an epoch and resold to a happily gullible media.

This happened again this week when Georges Mougin told the world that newfangled computer models just happened to confirm what he'd long thought: that icebergs could be transported economically to Africa. Here, we look back at the many failures and successes (there are some!) of towing icebergs from the early 19th century to today.

…[/font][/font]

[OKIsItJustMe]

3. Larsen B is not far behind

(From May 2015)
https://www.nasa.gov/press-release/nasa-study-shows-antarctica-s-larsen-b-ice-shelf-nearing-its-final-act

About NASA’s IceBridge:

[hatrack]

4. Sure, what's left of it . . .

Larsen A's been gone, what, 20 years already?

[OKIsItJustMe]

5. How time flies

That sounds about right.

Edit: Yes, January 1995: http://earthobservatory.nasa.gov/Features/WorldOfChange/larsenb.php

… The northernmost section of the Larsen Ice Shelf Complex, called Larsen A, lost about 1,500 square kilometers of ice in an abrupt event in January 1995. …

[CrispyQ]

6. That was fascinating!

And terrifying - that we aren't doing anything significant about it.

Many of the bergs were too tall and narrow to float upright. They toppled over and spread out across the bay like a neat row of books that had been knocked off a shelf.

[OKIsItJustMe]

7. "doing anything significant about it."

About what!? Is something going on!?

Oh… is Antarctica still melting? … Yeah, OK, whatever…

I see Trump is going to going to build the wall and charge Mexico for it!
https://twitter.com/realDonaldTrump/status/817329823374831617

[OKIsItJustMe]

8. Giant iceberg set to calve from Larsen C Ice Shelf

https://www.bas.ac.uk/media-post/iceberg-calve-larsen-ice-shelf/

[font face=Serif][font size=5]Giant iceberg set to calve from Larsen C Ice Shelf[/font]

6 January, 2017

[font size=4]A huge iceberg, roughly the size of Norfolk, looks set to break away from the Larsen C ice shelf on the Antarctic Peninsula. Larsen C is more than twice the size of Wales. Satellite observations from December 2016 show a growing crack in the ice shelf which suggests that an iceberg with an area of up to 5,000 km² is likely to calve soon.[/font]

[font size=3]British Antarctic Survey researchers have a long running research programme to monitor ice shelves from both above and below to understand the causes and implications of the rapid changes observed in the region.

During the current Antarctic field season, a glaciology research team has been on Larsen C using seismic techniques to survey the seafloor beneath the ice shelf. Because a break up looks likely the team has not set up camp on the ice as usual. Instead they have made field trips by twin otter aircraft supported from Rothera Research Station.

Ice shelves in normal situations produce an iceberg every few decades. There is not enough information to know whether the expected calving event on Larsen C is an effect of climate change or not, although there is good scientific evidence that climate change has caused thinning of the ice shelf. Once the iceberg has calved the big question is whether the entire ice sheet may collapse. This is something that British Antarctic Survey teams have been monitoring and why glaciologists were deployed to work on Larsen C in the past few weeks.

…[/font][/font]

[Hum]

9. From Climate Central:

The stability of ice shelves is important because they help buttress the huge glaciers that feed them. When an iceberg calves off an ice shelf, there is less ice to push back on the glaciers, causing them to speed up. In a stable system, the front of the ice shelf eventually moves forward until the whole system is once again in balance.

While calving is a natural process, it can be driven into overdrive by the warm ocean waters that are lapping away at the ice shelves that fringe Antarctica. When calving events happen too quickly in succession, the glacier-ice shelf system doesn’t have time to rebalance, which can result in glaciers continuing to speed their flow, bringing more and more ice into the oceans and raising sea levels.

This is what happened with Larsen C’s northern neighbors, Larsen A and B, which collapsed spectacularly in 1995 and 2002, respectively. The glaciers that had fed Larsen B flowed six times faster after its demise.

The world’s oceans have already risen by an average of 8 inches over the last century from a combination of water added by ice melt and the expansion of ocean waters as they warm. The entire West Antarctic Ice Sheet, of which Larsen C is a part, holds enough ice to raise sea levels by another 10 to 13 feet if it were all to melt.

http://www.climatecentral.org/news/large-iceberg-poised-to-break-off-antarctica-21028

Plus, that's more fresh water turning into undrinkable sea water.

[muriel_volestrangler]

11. Iceberg insists it can thrive on its own after winning referendum to leave Antarctica

One of the ten biggest icebergs ever recorded is planning to leave Antarctica immediately after comprehensively winning a referendum on the matter.
...
“The liberal elites will tell you the only way for us to survive is by clinging on to the antiquated Antarctic, but who needs experts? We will not only survive, we will thrive as we move off into warmer climates to follow our own destiny.

“We will be out there, floating somewhere in the middle of the Atlantic Ocean, and everyone will want to come and see us, and why wouldn’t they. We’re the tenth biggest iceberg. Within twenty years we could be the biggest iceberg ever – think big people!
...
Although expert opinion suggests the breakaway is a bad idea for the iceberg’s long-term prospects, many angry icerbergers have dismissed their so-called expert opinions as nothing more than biased rhetoric designed to hold back true iceberg patriots.

http://newsthump.com/2017/01/06/iceberg-insists-it-can-thrive-on-its-own-after-winning-referendum-to-leave-antarctica/

[hatrack]

12. Antexit?