Rapid melting of the world's largest ice shelf linked to solar heat in the ocean

Rapid melting of the world's largest ice shelf linked to solar heat in the ocean
The Ross Polynya where solar heat is absorbed by the ocean. The vertical wall of the ice front stretches a distance of 600 km. Credit: Poul Christoffersen

An international team of scientists has found part of the world's largest ice shelf is melting 10 times faster than expected due to solar heating of the surrounding ocean.

In a study of Antarctica's Ross Ice Shelf, which covers an area roughly the size of France, the scientists spent several years building up a record of how the north-west sector of this vast ice shelf interacts with the ocean beneath it. Their results, reported in the journal Nature Geoscience, show that the ice is melting much more rapidly than previously thought due to inflowing .

"The stability of ice shelves is generally thought to be related to their exposure to warm deep ocean water, but we've found that solar heated surface water also plays a crucial role in melting ice shelves," said first author Dr. Craig Stewart from the National Institute of Water and Atmospheric Research (NIWA) in New Zealand, who conducted the work while a Ph.D. student at the University of Cambridge.

Although the interactions between ice and ocean occurring hundreds of metres below the surface of ice shelves seem remote, they have a direct impact on long-term sea level. The Ross Ice Shelf stabilises the West Antarctic ice sheet by blocking the ice which flows into it from some of the world's largest glaciers.

"Previous studies have shown that when ice shelves collapse, the feeding glaciers can speed up by a factor or two or three," said co-author Dr. Poul Christoffersen from Cambridge's Scott Polar Research Institute. "The difference here is the sheer size of Ross Ice Shelf, which over one hundred times larger than the we've already seen disappear."

The team collected four years of data from an oceanographic mooring installed under the Ross Ice Shelf by collaborators at NIWA. Using instruments deployed through a 260 metre-deep borehole, the team measured temperature, salinity, melt rates and ocean currents in the cavity under the ice.

The team also used an extremely precise custom-made radar system to survey the changing thickness of the ice shelf. Supported by Antarctica New Zealand and the Rutherford Foundation's Scott Centenary Scholarship at the Scott Polar Research Institute, Dr. Stewart and Dr. Christoffersen travelled more than 1000 km by snowmobile in order to measure ice thicknesses and map basal melt rates.

Rapid melting of the world's largest ice shelf linked to solar heat in the ocean
Cambridge and NIWA scientists traverse 1,000 km on the Ross Ice Shelf. Credit: Poul Christoffersen

Data from the instruments deployed on the mooring showed that solar heated surface water flows into the cavity under the ice shelf near Ross Island, causing melt rates to nearly triple during the summer months.

The melting is affected by a large area of open ocean in front of the ice shelf that is empty of sea ice due to strong offshore winds. This area, known as the Ross Sea Polynya, absorbs solar heat quickly in summer and this solar heat source is clearly influencing melting in the ice shelf cavity.

The findings suggest that conditions in the ice shelf cavity are more closely coupled with the surface ocean and atmosphere than previously assumed, implying that melt rates near the ice front will respond quickly to changes in the uppermost layer of the ocean.

"Climate change is likely to result in less sea ice, and higher surface temperatures in the Ross Sea, suggesting that melt rates in this region will increase in the future," said Stewart.

The potential for increasing melt rates in this region has implications for ice shelf stability due to the shape of the ice shelf. Rapid melting identified by the study happens beneath a thin and structurally important part of the ice shelf, where the ice pushes against Ross Island. Pressure from the island, transmitted through this region, slows the flow of the entire ice shelf.

"The observations we made at the front of the ice shelf have direct implications for many large glaciers that flow into the ice shelf, some as far as 900 km away," said Christoffersen.

While the Ross Ice Shelf is considered to be releatively stable, the new findings show that it may be more vulnerable than thought so far. The point of vulnerability lies in the fact that that solar heated flows into the cavity near a stabilising pinning point, which could be undermined if basal melting intensifies further.

The researchers point out that melting measured by the study does not imply that the ice shelf is currently unstable. The ice shelf has evolved over time and ice lost by melting due to inflow of warm water is roughly balanced by the inputs of ice from feeding glaciers and snow accumulation. This balance is, however, depending on the stability provided by the Ross Island pinning point, which the new study identifies as a point of future vulnerability.


Explore further

Warm winds in autumn could strain Antarctica's Larsen C ice shelf

More information: Basal melting of Ross Ice Shelf from solar heat absorption in an ice-front polynya, Nature Geoscience (2019). DOI: 10.1038/s41561-019-0356-0 , https://www.nature.com/articles/s41561-019-0356-0
Journal information: Nature Geoscience

Citation: Rapid melting of the world's largest ice shelf linked to solar heat in the ocean (2019, April 29) retrieved 20 September 2019 from https://phys.org/news/2019-04-rapid-world-largest-ice-shelf.html
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Apr 29, 2019
so now there is 'spot ' heating caused by 'global' warming .

i'm going to switch to light bulbs above to boil my water

Apr 29, 2019
fight the power , fight the fake news , enemy of the people

https://advances....093.full

Apr 29, 2019
The fake man himself trying to talk about "fake news" funny indeed ;) The enemy of the people is the enemy of the environment, and that would purely be Fossil Fuels !

Apr 29, 2019
fight the power , fight the fake news , enemy of the people

https://advances....093.full


From the paper

"We do not hypothesize that elevated heat flux below the WAIS explains the instability of the ice sheet, nor that heat flux measured at SLW is regionally representative; however, locally elevated basal heat flux may help researchers to understand why parts of some ice sheets have been so sensitive to recent changes in climate and oceanic conditions"

fight the power , fight the fake news , enemy of the people, it fits but not the way you intended.

Apr 29, 2019

"We do not hypothesize that elevated heat flux below the WAIS explains the instability of the ice sheet, nor that heat flux measured at SLW is regionally representative; however, locally elevated basal heat flux may help researchers to understand why parts of some ice sheets have been so sensitive to recent changes in climate and oceanic conditions"

fight the power , fight the fake news , enemy of the people, it fits but not the way you intended.

LMAO.
You (not the Chicken Littles) have to wonder, why research into intense geothermal activity would seek to mention climate? Well, the response from the Chicken Little above answers that. It's purely to fool the ignorant. A check of their reference reveals, no relevance to climate.

AGW Cult "science", it does NOT fit, and is exactly the way they intended. Blatant lies for their hungry Chicken Littles.

Apr 29, 2019
well, now we have our scheduled propaganda from auntieoral.
agitpropping from it's circuit-board at one of the russuan & saudi axis Dark Web sites.

Apr 29, 2019
Russia seems to have software that creates false accounts and post pre-preprared messages to different blogs across the world to try to influence public opinion and create a debate around global warming on information sites. I wish there would be an investigation on those Steves and snoosebaum and similar accounts. They should be false accounts and not genuine persons behing them, and should be manipulated by an organization spreading false news.
I think that this is what we are facing, Europe should pursue this investigation.

Apr 29, 2019
да товарищи трудящиеся мира объединяются !!

Apr 29, 2019
LMAO.
You (not the Chicken Littles) have to wonder, why research into intense geothermal activity would seek to mention climate? Well, the response from the Chicken Little above answers that. It's purely to fool the ignorant. A check of their reference reveals, no relevance to climate.

Then why did you reference it here?
Fire below, ice above: volcanoes, glaciers and sea level rise
https://climate.n...el-rise/

https://phys.org/...ies.html

Apr 29, 2019
I wish there would be an investigation on those Steves and snoosebaum and similar accounts. They should be false accounts and not genuine persons behing them, and should be manipulated by an organization spreading false news.
I think that this is what we are facing, Europe should pursue this investigation.


If you believe this you have to admit that the Russians play a long game, I've been posting on this site since August 29, 2008.

Apr 29, 2019
ahh, snoozebum, still whoring for pimp putin's KGB canal.

What? The saudis won't pay you more?
Well, they do know how to price a traitor.
Plenty of other denier's offering themselves for sale to the highest bidder.

Apr 29, 2019
Then why did you reference it here?
Fire below, ice above: volcanoes, glaciers and sea level rise
https://climate.n...el-rise/

Go back and look at the links I posted in that other phyorg thread. They are all about research into how intense geothermal activity is affecting the icecaps in Antarctica and/or Greenland. Yet, they chose to make unsubstantiated claims about climate change, providing no data, irrelevant references or none at all. Why? Because the AGW Cult knows that their ignorant flock will be satisfied with just words..er..excuse me..lies and not bother to seek validation.

Apr 29, 2019
Then why did you reference it here?
Fire below, ice above: volcanoes, glaciers and sea level rise
https://climate.n...el-rise/

Go back and look at the links I posted in that other phyorg thread. They are all about research into how intense geothermal activity is affecting the icecaps in Antarctica and/or Greenland. Yet, they chose to make unsubstantiated claims about climate change, providing no data, irrelevant references or none at all. Why? Because the AGW Cult knows that their ignorant flock will be satisfied with just words..er..excuse me..lies and not bother to seek validation.


So you think it's all a big conspiracy. How unoriginal.

May I ask why you posted the links, what were you trying to prove?

Apr 29, 2019
@antigoracle.
geothermal activity is affecting the icecaps in Antarctica and/or Greenland. Yet, they chose to make unsubstantiated claims about climate change, providing no data, irrelevant references or none at all. Why?
All Russian/GOP/Fossil troll-factory 'spiels' were refuted long ago, mate. Either you're a bot-posting troll-stooge, or you're deliberately 'forgetting' what I have been pointing out for years now re ice-covered volcanic hot-spots:

1) such volcanic heat inputs have always been a part of the dynamics;

2) AGW-related warming/thinning of ice-cover creates less pressure; and hence allow more volcanic upwellings to bring more heat to underside of the ice cover.

3) Feedback between warming/melting and lessening-pressure on volcanic hot-spots, is increasing during transition from previous to evolving temp/pressure balances in such regions.

4) When this (and oceanic/other) 'heat/CO2 buffering' is exhausted, a 'Tipping Point' will bring disastrous dynamics.

Apr 29, 2019
well auntieoral,
your reliance on your ouiijabored for collecting anti-science fraudulent- flatulence is a real snoozefistula.
Your programmer & Dark Web operators been sucking down liters of potato-shine?

Again?

Apr 29, 2019
May I ask why you posted the links, what were you trying to prove?

Why did you cherry-pick every irrelevant and unsubstantiated reference to climate, in those links?

Apr 29, 2019
golly gee, Stewie. Who would've thunk that "solar heated surface water also plays a crucial role in melting ice shelves,". This is wondrous news!!
:)

Apr 29, 2019
Then why did you reference it here?
Fire below, ice above: volcanoes, glaciers and sea level rise
https://climate.n...el-rise/

Go back and look at the links I posted in that other phyorg thread. They are all about research into how intense geothermal activity is affecting the icecaps in Antarctica and/or Greenland. Yet, they chose to make unsubstantiated claims about climate change, providing no data, irrelevant references or none at all. Why? Because the AGW Cult knows that their ignorant flock will be satisfied with just words..er..excuse me..lies and not bother to seek validation.

says antigoracle

That 's a good, informative link from NASA. Mostly concerning the 'hot spots' under the ice that melt the glaciers for sea rise. But the link also has to mention AGW to give 'lip service' to those who don't believe that Nature is at fault. It must be humans causing the melting or else.

Apr 29, 2019
Meanwhile in real life the seas are rising 3 or so mm/yr!!! This figure has not changed much in 100s of years. Before that they rose at a much grater rate due to the end of an ice age.

But corrupted science continues to scare the children with pure propaganda and those who have the belief system of a child.

Apr 29, 2019
https://www.youtu...Gl96Rt4o

I think the most amusing thing is that deniers deny both heat and cold.

Apr 30, 2019
Meanwhile in real life the seas are rising 3 or so mm/yr!!! This figure has not changed much in 100s of years. Before that they rose at a much grater rate due to the end of an ice age.

But corrupted science continues to scare the children with pure propaganda and those who have the belief system of a child.
says MR166

I would like to know with what they are measuring this increase in height of sea rise. Do they implant a piece of wood or metal into a concrete form and stick it in the sand or seashore somewhere? Do they account for waves sploshing onto the wood or metal far above the 3 mm height? You know, ocean waves have this bad habit of constantly moving up, down, up, down and getting everything wet. Even the most accurate measurement can't be very accurate when measuring wave action. It would be nice if the sea would just inch up gradually on the measuring stick without rising and falling, wouldn't it? How lovely that would be.

Apr 30, 2019
I'd say the cesspools the deniers said were safe for hundreds of years overflowing onto their front lawns would tell them everything they need to know.

Just sayin'.

Apr 30, 2019
I'd say the cesspools the deniers said were safe for hundreds of years overflowing onto their front lawns would tell them everything they need to know.

Just sayin'.


LOL What is it with Da Schitts fascination/fixation on butts, arses and cesspools? Is he gay?

Apr 30, 2019
Hey, you're the one told them it would never happen.

And it's in the newspapers. Maybe you forgot. Bet they don't.

Some of those boys are meaner than cat piss.

And they all know how to use a rope.

Apr 30, 2019
Just so you don't forget: https://phys.org/...nks.html

A billion dollars.

Spend and spend Republicans. How much of that billion dollars worth of property damage you think those folks will get back?

Apr 30, 2019
May I ask why you posted the links, what were you trying to prove?

Why did you cherry-pick every irrelevant and unsubstantiated reference to climate, in those links?

I quoted extracts from your links to show that none of them supported your argument as none of them show that geothermal activity has increased and is causing the accelerated ice loss. Claiming that only those parts that you agree with can be true and the rest is a deliberate lie is a good example of a self-sealing argument and strong indicator of conspiracist ideation.

https://www.logic...Argument

Apr 30, 2019
This is the sort of science that is supported because our science agencies know that global warming is real and serious. Whilst it gives us yet more real world confirmation of global warming it is being done to gain a better understanding of how warming impacts at the interface of ice and ocean will play out in a region of great significance.

Apr 30, 2019
Da it trying to claim that sea level rise is ruining septic systems in Miami\Dade Florida. Why should I feel sorry for someone who built their home in what was once wetlands. If your home is destroyed by 3mm/year sea level rise you made the mistake not me.

https://tidesandc...=8723170

I will look for a new chart that goes past 1980. Perhaps another town nearby.

Apr 30, 2019
Cedar Key Fla. 2mm/year

https://tidesandc...=8727520

Apr 30, 2019
As our society loses it's moral compass lying, cheating and stealing become commonplace. To prove my point just leave your college dorm room unlocked for a few hours and see what happens. These are the very same people that are writing government funded papers proving AGW.

Apr 30, 2019
oh deer. I'd hoped that ms666 had been warned off about peeking into the windows at school dorms.

It is proof that the Earth is not warming up because ms666 wears that overcoat everywhere he/she/it skulks.

Huh? Whatta yah mean the air temperature is not why it wears that overcoat?

Ohhh...gross!

Apr 30, 2019
Yup RR we live in a valueless society. All people care about is free sh*t, access to bathrooms of the opposite sex and their precious marijuana.


Apr 30, 2019
fossil fuel was once life, release it and the earth will make it live again

https://www.natur...mate3004

May 01, 2019
@snoosebaum.
fossil fuel was once life, release it and the earth will make it live again
You posted that silly troll-factory meme more than once before in other threads, mate. I now yet again remind you of what I said to you then:
The sort of life way back then was not the sort of life now.
See? Dinosaurs and other non-hominids were adapted for such conditions as prevailed back then; but if such conditions returned, then you, your family/descendants would find it 'less than tolerable'; ie, downright deadly, in fact. Do you have a 'death wish' for yourself and your progeny, @snoosebaum? Sounds like it. Or else you're just yet another of Putin's/Trump's 'weaponised stupids' which they have been playing for suckers/stooges. Either way, not good, mate. Rethinkit.

May 02, 2019
Snooseloose antigoracle sockpuppet and the rest of his sockies overworking that pea to prove himself dumbest baboon of the year... guess what... at this pace, you will outperform your competition, ...well what competition... lol

May 02, 2019
As our society loses it's moral compass lying, cheating and stealing become commonplace. To prove my point just leave your college dorm room unlocked for a few hours and see what happens. These are the very same people that are writing government funded papers proving AGW.

No Dimwit, AGW is proven not written denier propaganda. On the other hand you have sucked your sore thumb dry putting up baseless and utterly idiotic comments along with your sockpuppets, but keep at it the world continues to watch..great fun.. :)

May 02, 2019
@MR166.
As our society loses it's moral compass lying, cheating and stealing become commonplace.
You just described in a 'nutshell' the modus operandi by which Trump, Putin, the big multinational corporations/banks accumulated their riches, mate! They are the ones who hide their ill-gotten gains in secretive tax-havens; where big money (acquired by cheating, lying and stealing from those who actually worked to create the wealth by honest toil) goes to hide from retribution. Being shafted by the global criminal mafias, and the crooked politicians they buy/blackmail into helping make laws/redistributions which keep those criminals/politicians in power/wealth dominance is not conducive to 'trust' in authority/institutions being corrupted like Trump/Putin have done. Little wonder young people have lost all respect for those (like you) who berate them while giving a 'free pass' to the likes of Putin/Trump etc who steal the fruits of others' labor! Bad.

Wake up, mate. :)

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