Warming ocean water undercuts Antarctic ice shelves

From the UNIVERSITY OF COLORADO AT BOULDER

antarctica-image

“Upside-down rivers” of warm ocean water threaten the stability of floating ice shelves in Antarctica, according to a new study led by researchers at the University of Colorado Boulder’s National Snow and Ice Data Center published today in Nature Geoscience. The study highlights how parts of Antarctica’s ice sheet may be weakening due to contact with warm ocean water.

“We found that warm ocean water is carving these ‘upside-down rivers,’ or basal channels, into the undersides of ice shelves all around the Antarctic continent. In at least some cases these channels weaken the ice shelves, making them more vulnerable to disintegration,” said Karen Alley, a Ph.D. student in CU-Boulder’s Department of Geological Sciences and lead author of an analysis published today in Nature Geoscience.

Ice shelves are thick floating plates of ice that have flowed off the Antarctic continent and spread out onto the ocean. As ice shelves flow out to sea, they push against islands, peninsulas, and bedrock bumps known as “pinning points.” Contact with these features slows the flow of grounded ice off the continent. While ice shelves take thousands of years to grow, previous work has shown that they can disintegrate in a matter of weeks. If more ice shelves disintegrate in the future, loss of contact with pinning points will allow ice to flow more rapidly into the ocean, increasing the rate of sea level rise.

“Ice shelves are really vulnerable parts of the ice sheet, because climate change hits them from above and below,” said NSIDC scientist and study co-author Ted Scambos. “They are really important in braking the ice flow to the ocean.”

The features form as buoyant plumes of warm and fresh water rise and flow along the underside of an ice shelf, carving channels much like upside-down rivers. The channels can be tens of miles long, and up to 800 feet “deep.”

When a channel is carved into the base of an ice shelf, the top of the ice shelf sags, leaving a visible depression, or “wrinkle”, in the relatively smooth ice surface. Alley and her colleagues mapped the locations of these wrinkles all around the Antarctic continent using satellite imagery, as well as radar data that images the channels through the ice, mapping the shape of the ice-ocean boundary.

The team also used satellite laser altimetry, which measures the height of an ice shelf surface with high accuracy, to document how quickly some of the channels were growing. The data show that growing channels on the rapidly melting Getz Ice Shelf in West Antarctica can bore into the ice shelf base at rates of approximately 10 meters (33 feet) each year.

The mapping shows that basal channels have a tendency to form along the edges of islands and peninsulas, which are already weak areas on ice shelves. The team observed two locations where ice shelves are fracturing along basal channels, clear evidence that basal channel presence can weaken ice shelves to the point of breaking in vulnerable areas.

Ice shelves are thick floating plates of ice that have flowed off the continent and out onto the ocean. As ice shelves flow out to sea, they push against islands, peninsulas, and bedrock bumps known as “pinning points”. Contact with these features slows the ice flowing off the continent. If ice shelves disintegrate in the future, loss of contact with pinning points will allow ice to flow more rapidly into the ocean, increasing rates of sea level rise.

While no ice shelves have completely disintegrated due to carving by basal channels, the study points to the need for more observation and study of the features, said co-author… “It’s feasible that increasing ocean temperatures around Antarctica could continue to erode ice shelves from below.”

###

The study, “Impacts of warm water on Antarctic ice shelf stability through basal channel formation,” was led by University of Colorado Boulder Ph.D. student Karen Alley, who worked with coauthors Ted Scambos of NSIDC and Matthew Siegfried and Helen Fricker of Scripps Institute of Oceanography. Their work was funded in part by NASA and the U.S. Geological Survey.

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Editor
March 15, 2016 3:02 am

In other words, we’ve got a new toy, look what we have seen!
Is there any evidence this is not a natural process that has been occurring for millennia?

mikebartnz
Reply to  Paul Homewood
March 15, 2016 3:39 am

Exactly. They are carrying on as if it has never happened before and they need to look at what may be causing these warm water flows eg. are they caused by under water geothermal activity or what?

Billy Liar
Reply to  mikebartnz
March 15, 2016 6:53 am

The Getz ice shelf just happens to be located adjacent to Siple Island which has as its most prominent feature the dormant shield volcano, Mount Siple.
There is no possibility whatsoever that a volcano that has been active in the Holocene could have any associated geothermal activity; no sir, none at all.
https://en.wikipedia.org/wiki/Mount_Siple
http://www.skimountaineer.com/ROF/OcAnt/Siple/SipleMap.jpg

Neo
Reply to  Paul Homewood
March 15, 2016 6:29 am

A new idea.
Ice shelves have water underneath which is warmer than ice. (3rd grade stuff)
“Shelves” would most certainly indicate that the area under the shelf is void of ice.

george e. smith
Reply to  Paul Homewood
March 15, 2016 6:41 am

Um; please sir, Mr. PhD student advisor Professor;
But doesn’t the whole Pacific Ocean and Atlantic Ocean slosh back and forth through there about twice a day, and aren’t both of those oceans mainly liquid and warmer than ice ??
Wasn’t this happening last year as well ??
G

george e. smith
Reply to  george e. smith
March 15, 2016 7:07 am

Well my Glaciologist guru in Greenland; Svend, sent me a picture of a broken section of the an Antarctic ice shelf that had broken up due to tidal bulges lifting it up twice a day, and he pointed out the adjacent piece about the same area, that was some amount lower in height than the main body, with an interface cliff.
Svend pointed out that the thinner part was a piece that broke up 50 years earlier, and had grown back due to sea ice freezing and then snow on top.
So they break up all the time and don’t take thousands of years to regrow.
I’m not saying this student didn’t find the river channels he says he did or the PR says so. But the ice has been coming and going.
I don’t see any flock of off shore islands pinning the ice sheets.
That’s like saying that the cruise ships parked at the Docks in San Francisco, are stopping the whole of Russian Hill from sliding into SF Bay !
G
PS Svend can get photos of Antarctic ice any time the satellite delivery van comes over his igloo on Greenland.

george e. smith
Reply to  george e. smith
March 15, 2016 1:56 pm

“””””….. Their work was funded in part by NASA and the U.S. Geological Survey. ……”””””
Actually it was me and my fellow taxpayers, who put groceries on Ms. Alley’s table.
g

ATheoK
Reply to  george e. smith
March 15, 2016 6:21 pm

Scampos had a significant part in guiding this idiocy along with Ms. Alley.
Not to forget that if the water is liquid, than it is almost certainly warmer than the ice. Meaning that every ice sheet floating on oceans worldwide suffer from some ‘warm water’ currents and ice melting.
Horrible science protocol and method in action; a fault shared by NSIDC, Scripps Institute of Oceanography and University of Colorado CU-Boulder’s Department of Geological Sciences. Maybe one of them can explain why they allow dreadfully bad science?
Attention that apparently the pal reviewers failed to perform or provide.

expat
Reply to  george e. smith
March 15, 2016 11:24 pm

“he data show that growing channels on the rapidly melting Getz Ice Shelf in West Antarctica can bore into the ice shelf base at rates of approximately 10 meters (33 feet) each year.”
“The channels can be tens of miles long, and up to 800 feet “deep.”
So……………These channels are proof of AGW how?
““Ice shelves are really vulnerable parts of the ice sheet, because climate change hits them from above and below,”
Doesn’t Antarctic air temps stay below freezing all 12 months of the year and water temps stay near or below 0?

Robert Wykoff
Reply to  Paul Homewood
March 15, 2016 8:16 am

Exactly. Isn’t it amazing how new technology is always invented just in time to detect these catastrophic threats to the environment. Just like the technology to detect holes in ozone layers was developed just in time to detect a hole in the ozone layer

Reply to  Robert Wykoff
March 15, 2016 9:38 am

OMG! We must act now to save the world from global inundation by sea level rise! The Paris Climate Accord must be amended to include a ban on all undersea warming currents in the Antarctic. We must pass legislation that will stop this undersea thermal venting! We must increase the funding to studies that will research the obvious ties between these undersea rivers and increased atmospheric CO2 levels which are driving the Anthropogenic Climate Change which will raise global temperatures and exacerbate the flooding problems in the Malvines!
Sarcasm off…

george e. smith
Reply to  Robert Wykoff
March 15, 2016 2:09 pm

Well if they just discovered this effect, then it is far too early maybe by thousands of years to say it is anything unusual, so we shouldn’t worry about it till they have more data.
Well just in time for Ms. Alley to start collecting from the social security fund my kids are paying into (along with me).
Perhaps I could get a free copy of your thesis Ms. Alley, since I paid for it.
You oughta go on the Shark Tank program, and see if you can talk any of those money bags into investing in your upside down canyon rivers project. Maybe you can market it.
What an idea; let venture capitalists invest in PhD student theses. That way, they will have some idea that they are studying something useful.
I mean who wants to try and make a killing, by studying the sex life of the hermaphroditic Pololo worm.
Well we do know that after metamorphosis, their adult form is tarpon guano.
G

jim Steele
Reply to  Paul Homewood
March 15, 2016 8:18 am

Sagging surface ice suggesting basal melting and instability was noted in the Amundsen Sea region over 80 years ago, before CO2 had risen to any significant concentrations.

Richard G.
Reply to  jim Steele
March 15, 2016 8:41 am

And just how warm is this water? No mention that I saw of actual temps, but just a quick skim. Try 0 c?
“The features form as buoyant plumes of warm and fresh water rise and flow along the underside of an ice shelf, carving channels much like upside-down rivers. The channels can be tens of miles long, and up to 800 feet “deep.”
https://www.windyty.com/?sst,2016-03-23-12,-90.000,-76.897,4

george e. smith
Reply to  jim Steele
March 16, 2016 11:58 am

Well in principle the water can be colder than the ice, since the ice is basically frozen fresh water. In some way or another, the segregation coefficient would exclude the salts to an extent where we can call the ice fresh water. (could have brine inclusions)
But sea water freezes somewhat below zero deg C, so you could have stable fresh water ice at zero Deg. C, and liquid ocean colder than that.
But mostly, once the ice is formed, it will drop in Temperature due to colder air temperatures, and poor solar energy absorption.
G

Seth
Reply to  Paul Homewood
March 16, 2016 1:06 am

In other words, we’ve got a new toy, look what we have seen!

Science is a bit like that.

Is there any evidence this is not a natural process that has been occurring for millennia?

Why would there be any such evidence? The point is we can know more about how ice shelves break up now, which is important to predicting sea level rise, which in turn is economically important.
Also upside down rivers cut into the underside of ice shelves are cool.

March 15, 2016 3:04 am

” … threaten the stability of floating ice shelves in Antarctica …”
I don’t believe that, but for the sake of discussion, what if that were true? Why should I care?
Life flourished on this planet when there were not glaciers and now I should morn any piece of one disappearing for any reason?

emsnews
Reply to  markstoval
March 15, 2016 4:25 am

These clowns want another Ice Age. I have said this before and every ‘study’ proves it. Melting ice=evil is the prevailing storyline. This is scary. Their propaganda has so screwed up their brains that they now believe that if glaciers and ice packs aren’t dominating the planet, we are doomed.
This strange belief system infects everything they do and think which they then try to use to ‘fix’ a warm planet and all their futuristic schemes revolve around eliminating CO2 to the point of plant starvation while they force another Ice Age on us all.

Neo
Reply to  markstoval
March 15, 2016 6:31 am

“floating ice shelves” So, these shelves are floating on .. what ? argon, methane .. water.
Water seems to be usually warmer than ice, so they will seek thermal equilibrium.

Luke
Reply to  markstoval
March 15, 2016 8:03 am

“should morn any piece of one disappearing for any reason?”
Think rising sea level. That will cost all of us billions of dollars.

Doonman
Reply to  Luke
March 15, 2016 10:01 am

It wont cost you a dime. Antarctica has been frozen solid for 500 million years and will continue to be so well after your decaying bones have returned to dust.

Jack
Reply to  Luke
March 15, 2016 12:00 pm

There is no observed acceleration of the sea level rise since it began being monitored by the tide gauges in America and Europe by the mid XIXth century.
http://www.sonel.org/spip.php?page=maregraphe&idStation=1736.php
20 centimeters rise in ~170 years at Brest (France)

JohnKnight
Reply to  Luke
March 15, 2016 3:01 pm

“Think rising sea level. That will cost all of us billions of dollars.”
I’m thinking rising BS level. That will cost us trillions of dollars.

David A
Reply to  Luke
March 15, 2016 3:57 pm

Not happening, unless 2mm per year worries you. The southern oceans SST is cooling. The only warming was detected near volcanically active areas.
Really, look it up.

catweazle666
Reply to  Luke
March 15, 2016 3:57 pm

Luke: “Think rising sea level.
The ice shelves are floating on the surface of the ocean, so their melting will not affect the sea level, so will cost us nothing at all.
Period.
Didn’t you learn about Archimedes’ Principle in school physics lessons?

Seth
Reply to  markstoval
March 16, 2016 1:08 am

I don’t believe that

On what basis?

but for the sake of discussion, what if that were true? Why should I care?

From the article:
If more ice shelves disintegrate in the future, loss of contact with pinning points will allow ice to flow more rapidly into the ocean, increasing the rate of sea level rise.

Reply to  Seth
March 16, 2016 2:36 am

Seth,
I don’t believe that because the sea level rise during the Holocene has been very small on a yearly basis and still is. There has been no change. The paper is garbage and goes against measured data.
By the way, did you know that measuring the level of the oceans is not very easy? Do you know why?

March 15, 2016 3:04 am

“Ice shelves are thick floating plates of ice that have flowed off the Antarctic continent and spread out onto the ocean. As ice shelves flow out to sea, they push against islands, peninsulas, and bedrock bumps known as “pinning points.” Contact with these features slows the flow of grounded ice off the continent. While ice shelves take thousands of years to grow, previous work has shown that they can disintegrate in a matter of weeks. If more ice shelves disintegrate in the future, loss of contact with pinning points will allow ice to flow more rapidly into the ocean, increasing the rate of sea level rise.”
Notice the discrepancy between the first and last sentences. Ice shelves are floating plates. If they disintegrate they will increase the rate of sea level rise. If they are floating they displace their own weight of water, hence they cannot increase the rate of sea level rise. (Archimedes, QED)

steveta_uk
Reply to  Dudley Horscroft
March 15, 2016 3:07 am

“loss of contact with pinning points will allow ice to flow more rapidly into the ocean”
They mean that land ice will more rapidly flow into the ocean when no longer blocked by floating sea ice.

Neo
Reply to  steveta_uk
March 15, 2016 6:36 am

Don’t think so. I think this means if the ice isn’t held up by high friction points with rising points of land, they will act like a Whamo “Slip-n-Slide” and slide into the ocean.

seaice1
Reply to  Dudley Horscroft
March 15, 2016 4:03 am

You missed a step in the argument. Ice shelves are floating plates. If they melt they allow ice to flow more rapidly into the ocean increasing the rate of sea level rise. The scientists who specialise in ice-shelves were aware of Archimedes’ principle after all.

Joe Crawford
Reply to  seaice1
March 15, 2016 4:43 am

” If they melt they allow ice to flow more rapidly into the ocean…”
It appears to me this would effect only that part of the ice that is already floating, which as Dudley said “cannot increase the rate of sea level rise.” I would think that the part of the plate that has not yet “flowed off the Arctic continent” is still grounded. It should only moved, like a glacier, when more snow is deposited at the head.

seaice1
Reply to  seaice1
March 15, 2016 5:05 am

Joe, think of it as fluid flow. If you restrict the outlet, the overall flow will be reduced. The ice sheet that is in contact with the pinning points resists the flow of ice from the interior. If there were no pinning points, you may well be right – the floating sea ice would make less difference. However, even without pinning points it must require some energy to move the ice, and so must slow the flow to some extent.
I imagine it like an inclined channel full of marbles connected to a channel in a flat table. You put marbles (or coins) in the top at a steady rate. If you go fast enough the marbles will reach a steady state. The inclined channel will fill to a certain place. The higher up the channel the marbles stack, the more weight is pushing on the marbles on the table. The more resistance in the table, the higher up the channel the balls will become. If you put rough sandpaper in the channel, the balls will go further up the incline. This is the equivalent of more ice on the land. If you then shorten the channel on the table, the balls will flow faster – that is the equivalent of ice moving from the land to the sea.

mebbe
Reply to  seaice1
March 15, 2016 10:33 am

I’ve never been to Antarctica but the tidewater glaciers I have been to are not held back by floating ice. Their terminal moraines of millions of tons of grounded gravel do resist glacial flow, whilst also shielding the snout from water erosion. The height of the glacier’s face will increase if flow exceeds advance, since this ice is being fed from levels a thousand metres above the outfall.

Joe Crawford
Reply to  seaice1
March 15, 2016 12:50 pm

seaice 1,
Rather than your channel full of marbles, I would think of it more an inclined channel containing a substance normally in the solid state (i.e., ice) that only becomes partially fluid when the force acting down the channel (i.e., gravity) is sufficient to overcome the resistance to its sliding down the channel. (Please don’t give me that old adage that resistance is only a function of normal force and independent of contact area.)
I am surely no expert (just a poor dumb old engineer) but from my limited reading I thought the rate of motion of a glacier is determined by how much snow (i.e. mass) is added to the upper portion. In this case, with a floating ice shelf at the bottom, it seems to me that all any grounding points for the ice shelf would do is to add the resistance of the grounding points to the total resistance of the inclined channel. And, the relationship between them being somewhat proportional to their areas, the grounding points and the floating ice shelf’s effect on glacial flow should be almost negligible.

ATheoK
Reply to  seaice1
March 15, 2016 6:55 pm

Blocked? Slowed? by sea ice?
Not a chance. Not so you’d notice.
The glaciers are already flowing because of the greater pressure inland. What is sea ice going to do?
If the sea ice refuses to move, the glacier will overtop it. At some point the sheer mass of moving ice will push the sea ice further out into the ocean. Where the completely natural process of warm, (than ice), water will melt sea ice underneath and along the edges.
Whatever pressure is causing the ice to flow will continue to cause the ice to flow. Ice isn’t flowing just because; it is flowing because the sheer mass of ice uphill or higher in elevation is forcing the ice to move. Think pneumatics.
Blocking a flow of water may temporarily slow a water flow; typically by filling up any available space. Water flow will continue to flow as long as pressure drives the water. Stopping a low pressure fluid is no big deal. Stopping ice flowing that has multiple billions of tons pressure behind it is imaginary. Even for immense sea ice shelves.

seaice
Reply to  seaice1
March 16, 2016 2:46 am

AtheoK “The glaciers are already flowing because of the greater pressure inland. What is sea ice going to do?” If it has pinning points it will slow the flow of ice from the land to the sea.
Using my imagined experiment. Sea ice snaging on the sea bottom is like putting bumps on the table channel. This resist the flow, so the marbles on the incline channel stack up higher. This is very, very basic, and toally uncontroversial stuff.
Another experiment. You have a tank of water with water flowing into it at a constant rate and flowing out of a tube at the bottom intpo a bathtub. The water flowing into the tank is poumped formthe bathtub. The system will reach a steady state where the flow in eqauls the flow out. There will be a certain amount of water in the tank and in the bathtub, and this will remain the same.
If you restrict the flow out of the tube the flow reduces. The level in the tank will rise, this increases the pressure at the bottom, so increases the flow until you reach a new steady state. Flow in again equals flow out, but we have more water in the tank and less in the bathtub. If you release the restriction, water will flow out faster than it flows in, and you will again reach the equilibrium. The level, in the bathtub will rise.
Now, the only reason this would not apply to the ice in the Antarctic is if the sea ice did not restrict the flow from the land. Since the ice must be pushed over the bumps on the pinning points, there must be a restriction to the flow. Even without pinning points, the ice must be moved out of the way. there must be some restriction.
Joe Crawford -“it seems to me that all any grounding points for the ice shelf would do is to add the resistance of the grounding points to the total resistance of the inclined channel.” Joe agrees with me – the pinning points must restrict the flow. The flow is related to the total resistance.
“the grounding points and the floating ice shelf’s effect on glacial flow should be almost negligible.” It depends what you mean by negligible. Yes, we are talking about very small percentage changes in the total mass of the ice. However, since the ice sheet is so vast, very small percentage change is enough to affect sea levels significantly.

Reply to  seaice1
March 16, 2016 3:22 am

Joe, think of it as fluid flow.
seaice1, ….. ice is not a fluid …… therefore it doesn’t flow.
Ice is the solid “crystalline” form of water (H2O) …… and therefore doesn’t bend or sag.
And seaice1, ….. the following quoted “claim” is not only asinine and silly, but also idiotic ta boot, …… to wit:

When a channel is carved into the base of an ice shelf, the top of the ice shelf sags, leaving a visible depression, or “wrinkle”, in the relatively smooth ice surface.

DUH, if the ocean water, warmer or otherwise, does per chance ….”carves or melts a channel into the base of a “floating” ice shelf” …… the channel that is created will remain full of water and the shelf ice above it is still floating on/in the water and there is no way in ell it can “bend or sag” into said “carved channel” even if it was capable of “bending or sagging”.

ATheoK
Reply to  seaice1
March 16, 2016 6:59 pm

“…Using my imagined experiment. Sea ice snaging on the sea bottom…”

So, land ice that is thoroughly grounded the full length of the glacier is going to be ‘stopped’ by some ‘snags’ on the bottom of the sea ice.
I doubt the glacier would even be much slowed.
Your armchair imagining ignores all of glacier science.

Reply to  Dudley Horscroft
March 15, 2016 4:24 am

And then there is this discrepancy, to wit:

When a channel is carved into the base of an ice shelf, the top of the ice shelf sags, leaving a visible depression, or “wrinkle”, in the relatively smooth ice surface.
The team observed two locations where ice shelves are fracturing along basal channels, clear evidence that basal channel presence can weaken ice shelves to the point of breaking in vulnerable areas.

So, the ice shelf is “sagging” in just the right places that they want it to “sag” …….. and that same ice shelf is “fracturing & breaking” in just the right places that they want it to “fracture & break”.
Vunderful, truly vunderful.
I wonder who it was that invented “sagging” ice ….. cause I don’t think Mother Nature had a hand in it?

seaice1
Reply to  Samuel C Cogar
March 15, 2016 5:24 am

I don’t see a discrepancy here. They can “see” the channels becasue of the sagging. They can detect the fracturing by other means -possibly radar, or cracks at the surface. They have detected fracturing along two of the channels. This is evidence that the channels are a weak point along which the fractures can occur.
Now, on its own, this is not conclusive. It is possible that the ice would have fractured anyway, even without the channels. Maybe the fractures occcur along the channels by coincidence. Since this is a press release and the not actual paper we do not get all the discussion and evidence that leads them to say it is clear evidence. Neverthless, this is not a discrepancy. The fracture occurs along the channel, therefore the channel is the weakest place, therefore since it is weaker than it would have been without the channel fracturing will occur more easily that without the channel.

Neo
Reply to  Samuel C Cogar
March 15, 2016 6:39 am

This sounds like a great Middle School experiment or science fair project.
I bet you to use a block of ice, or just empty the ice dispenser in your refrigerator onto an incline and video with a GoPro.

seaice1
Reply to  Samuel C Cogar
March 17, 2016 2:22 am

ATheoK “I doubt the glacier would even be much slowed.” Maybe not very much, but it doesn’t take very much to have a significant effect. A change in the mass if the ice shelf by a fraction of a percent is still a huge amount of ice.
You acknowledge that the principle is sound, and there must be some effect. Yet on the basis of apparently nothing at all you decide that the effect is too small to be significant.
“Your armchair imagining ignores all of glacier science.” In fact it is your armchair imagining that ignores the science. Glaciologists say the slowing has a significant effect. Your imaginings say the effect is too small to be significant.
Samuel “seaice1, ….. ice is not a fluid …… therefore it doesn’t flow.”
How do you think glaciers move? From Antarcticglaciers.org “Glaciers always flow downslope under the weight of their own gravity.” The glacier can flow by basal sliding, or by deformnation of the ice. “The ice crystals within the glacier orientate themselves in the direction of ice movement. This allows ice crystals to slide past one another.”
My simple model used marbles, which are also a solid.

Reply to  Samuel C Cogar
March 17, 2016 5:37 am

Posted quote by seaice1, to wit:

.” The glacier can flow by basal sliding, or by deformnation of the ice. “The ice crystals within the glacier orientate themselves in the direction of ice movement. This allows ice crystals to slide past one another.”

seaice1, …. iffen YOU BELIEVE the above is a scientific fact that claims the ice crystals in “glacial ice” will orientate themselves in the direction of ice movement and therefore allows ice crystals to slide past one another, ……. then there are two (2) important questions you MUST provide answers to in support of your beliefs, to wit:
#1 question: (a chicken or egg type) Which comes first, … the ice movement or the crystal orientation?
seaice1, …. You can’t have your cake and eat it too. You can’t be claiming that the ice movement is due to the orientation of the ice crystals …… and the ice crystal orientation is due to the movement of the ice.
#2 question: …. iffen the orientation of the ice crystals is directly responsible for the “downslope” movement of glacier ice …… then please tell us why all of the glacial ice has not slid or flowed off the top of Mt. Kilimanjaro after all of these past thousands of years?
As anyone can plainly see, the glacial ice is still there, to wit:
http://www.naturaltrekking.com/wp-content/uploads/2013/12/Climb-Mt.-Kilimanjaro-Kilimanjaro-Trek-Tour.jpg
NOTE: “Ice cores taken from Kilimanjaro’s Northern Ice Field (NIF) indicates that the glaciers there have a “basal age” of 11,700 years,[83]

ATheoK
Reply to  Samuel C Cogar
March 18, 2016 5:44 pm

“seaice1 March 17, 2016 at 2:22 am
ATheoK “I doubt the glacier would even be much slowed.” Maybe not very much, but it doesn’t take very much to have a significant effect. A change in the mass if the ice shelf by a fraction of a percent is still a huge amount of ice…”

The more ice uphill, the less an effect. To all apparent views without strain gauges testing every foot, the effect is indistinguishable from zero effect.

“…You acknowledge that the principle is sound…”

A bluntly false claim on your part. Stop putting false words in the mouths of others.

“…and there must be some effect. Yet on the basis of apparently nothing at all you decide that the effect is too small to be significant…”

On the basis of geology and glaciology. Again, you are delusional and making assumptions that you can neither prove or provide evidence for.

…“Your armchair imagining ignores all of glacier science.” In fact it is your armchair imagining that ignores the science. Glaciologists say the slowing has a significant effect. Your imaginings say the effect is too small to be significant…”

Ah, the fount of wisdom, confused and contrary as it is.
Last sentence first. So you admit that is what I demonstrated, not ‘acknowledge the principle is sound’. It is simply amazing that you can reach such absurd positions completely contrary to all evidence.
What glaciologists have made the claim that land bound glaciers are slowed down when they reach sea ice? And where is their evidence? Ship of fools Turney is not a legitimate glaciologist; he’s too busy killing inconvenient penguins.

george e. smith
Reply to  Dudley Horscroft
March 15, 2016 7:18 am

Well you almost got it right Dudley.
When floating sea ice melts, it cools the ocean water it is floating on to the tune of 80 calories per gram of ice, so the sea water shrinks as it cools, and the sea level goes down.
Too bad Archimedes didn’t do his experiment sitting in a block of ice floating on sea water.
Sea water has no maximum density down to its freezing point.
Anyone who doesn’t believe the ocean water melts the ice, should do these experiments.
#1 stand beside a cold water lake with some floating ice on it, in air temperature of zero deg. C, and take off all your clothes. Don’t worry there’s no wind. Time how long it takes you to freeze to death, or at least put your skivvies back on.
#2 Repeat experiment one, but with one change: before you start the stop watch, why don’t you go and jump in the lake !
G

Seth
Reply to  Dudley Horscroft
March 16, 2016 1:11 am

Notice the discrepancy between the first and last sentences. Ice shelves are floating plates. If they disintegrate they will increase the rate of sea level rise.
Did you read some of the sentences between those two. You copied them.

Contact with these features slows the flow of grounded ice off the continent.

M Seward
March 15, 2016 3:04 am

Another bunch of alarmist crap.
These turkeys have only just go the first data set on the subject and they are spinning it in terms of looming aramageddon. Science flavoured alarmism is all this is. There may be some actual science at the centre of it that goes to the mechanism of ice shelf breakup but so what, ice shelves have to break up somehow otherwise they would cover the planet if the creation mechanism keeps of ticking away.

emsnews
Reply to  M Seward
March 15, 2016 4:28 am

Exactly. Their belief is, lots of ice=ideal climate and warm weather=evil for all Emperor Penguins! All hail our Real Rulers, the Emperor Penguins who deliberately live in the coldest, most isolated place on earth and love it.

Neo
Reply to  M Seward
March 15, 2016 6:41 am

I can see how this proves that much of the macro-dynamics of ice is like the micro-dynamics of ice.
I think they threw in the Climate Change stuff so they could get funding.

M Seward
Reply to  Neo
March 15, 2016 1:01 pm

And they spun the alarmist drivel to get ongoing funding for their ‘important’ work that reveals the stunning discovery that ice floats on water and the water is slightly warmer, or that warmer water is free to flow underneath.
And other scientists are out there measuring gravity waves… what dorks, eh? Why would they bother? /sarc

Seth
Reply to  M Seward
March 16, 2016 1:18 am

Another bunch of alarmist crap.
Yeah. What crap. There’s no oceanic channels carved under the ice shelves by the ocean. They completely made that up, so that they could get a paper in Nature Geoscience. Transparent really. I hope the peer reviewers get their comeuppance.
These turkeys have only just go the first data set on the subject and they are spinning it in terms of looming aramageddon.
Yeah. Utter aramgeddon. “It’s feasible that increasing ocean temperatures around Antarctica could continue to erode ice shelves from below.” If people just believed statements like that they’d all convert to religion and start praying for peace from the plagues and famine. And the scorpion flies.
There may be some actual science at the centre of it that goes to the mechanism of ice shelf breakup
Don’t go reversing yourself. I was with you there for a while.
but so what, ice shelves have to break up somehow otherwise they would cover the planet if the creation mechanism keeps of ticking away.
Yeah. I bet they didn’t mention that in Nature Geoscience. The planet is not covered in glaicers, ergo, don’t bother with your alarmist crap science. Checkmate, University of Colorado.

spangled drongo
March 15, 2016 3:15 am

If there was a net increase in ice melt there would be an acceleration in SLR but:
“If we consider only 100 tide gauges with more than 80 years of recording the rise is only +0.25 mm/year. This naïve averaging has been stable and shows that the sea levels are slowly rising but not accelerating.”
http://www.sciencedirect.com/science/article/pii/S0964569116300205

Seth
Reply to  spangled drongo
March 16, 2016 1:30 am

On the other hand:
“Here we use a regression model with atmospheric pressure, wind, and climate indices as independent variables to quantify the contribution of internal climate variability to the sea level at nine tide gauges from around the world for the period 1920–2011. Removing this contribution reveals a statistically significant acceleration (0.022 ± 0.015 mm/yr2) between 1952 and 2011, which is unique over the whole period. Furthermore, we have found that the acceleration is increasing over time. This acceleration appears to be the result of increasing greenhouse gas concentrations, along with changes in volcanic forcing and tropospheric aerosol loading.”
http://onlinelibrary.wiley.com/doi/10.1002/grl.50731/full
And
“Second, in contrast to the previously reported slowing in the rate during the past two decades, our corrected GMSL data set indicates an acceleration in sea-level rise (independent of the VLM used), which is of opposite sign to previous estimates and comparable to the accelerated loss of ice from Greenland and to recent projections, and larger than the twentieth-century acceleration”
http://www.nature.com/nclimate/journal/v5/n6/full/nclimate2635.html

Gamecock
March 15, 2016 3:15 am

a Ph.D. student
A graduate student, then. They love to grant PH.D.s to people to give them authority.
‘allow ice to flow more rapidly into the ocean’
How will I sleep at night worrying about rapidly flowing ice? Wait . . . what?

Russell
March 15, 2016 3:22 am

Welcome to the Ship of FOOLs q=ship+of+fools+antarctic&biw=1024&bih=514&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjGjbjLyMLLAhVFyT4KHZs2A3gQsAQIKg

March 15, 2016 3:31 am

For once can anyone just provide some quantification of how much warmer these waters are now compared to 50 years ago? Well then, how about 100 years ago? Anything! Really, just give us some historical perspective. I want to know how things are different than the last 1,000 years. Please.
Nope. I forgot, just SOP in climateville.

Bloke down the pub
Reply to  cerescokid
March 15, 2016 4:02 am
emsnews
Reply to  cerescokid
March 15, 2016 4:31 am

Well, 28,000 years ago, the planet was in another Ice Age and it was bitter cold! And this, it seems, is what these guys think is ‘normal’ and frankly, it is ‘normal’ because all Interglacials feature sudden melting and then a sudden end and are much, much shorter than the ‘normal’ of a very cold planet climate.
Note how they are freaking out because it is warmer than when Washington crossed the river at Christmas to surprise the British troops.

chrisyu
Reply to  emsnews
March 15, 2016 7:47 am

frankly I think NYC looked better with a half mile thick glacier over it. Now that wonderful glacier is gone thanks to climate change…..

March 15, 2016 4:08 am

ARGO floats said the oceans were COOLING until the data was “Adjusted” by a “Climate Scientist…”

mikebartnz
Reply to  Michael Moon
March 15, 2016 6:06 pm

The data was adjusted because they didn’t like the results of the Argo data so preferred the ship intake data which for some bizarre reason they thought was more accurate.

catweazle666
Reply to  mikebartnz
March 17, 2016 3:13 pm

mikebartnz: “The data was adjusted because they didn’t like the results of the Argo data so preferred the ship intake data which for some bizarre reason they thought was more accurate.”
Nothing bizarre about it.
The ex-factory accuracy specification of the type of instrument used for measurement of engine room inlet temperatures is ±2°C, and AFAIK it is never recalibrated, as opposed to ± 0.002°C for the ARGO buoys, so there is a much wider error band on the graph to draw the temperature estimate line through.

ThermEng
March 15, 2016 4:31 am

A 0.1 C degree change in air temp would translate to a 0.01C change in water temp (which is invisible on a local scale). Wouldn’t this imply this is just defining a natural occurring process?

seaice1
Reply to  ThermEng
March 15, 2016 6:31 am

No. The relative heat capacity of air and water does not imply that this is a natural occuring process. It implies absolutely nothing about the origins of the process.

michael hart
Reply to  seaice1
March 15, 2016 9:05 am

but as others point out, merely saying it might, or might not, be normal and unexceptional is not the current best path to more funding.

David A
Reply to  seaice1
March 15, 2016 4:01 pm

Well your SUV is not causing the cooling of the southern oceans is it? Nor is it causing the volcanism noted in this very area.

Reply to  ThermEng
March 15, 2016 3:51 pm

seaice sez:
The relative heat capacity of air and water does not imply that this is a natural occuring process.
Nothing would imply a natural process to Mr. seaice.

seaice1
Reply to  dbstealey
March 16, 2016 1:52 am

A lot of things are natural processes. I have never said there are no natural processes. A glacier slowly flowing down a mountain is a natural process.
What I object to is stopping there. It is not scientific to say that since glacier flow is a natural process we don’t need to understand the mechanisms. To the simple observer ice is a solid and does not flow. There is a lot of knowledge required before we can understand how and why glaciers flow.
Same with the climate. Whatever natural changes are occuring, we want to understand. It is not enough to simply say “It is natural” and stop there.
So natural or not makes no difference, we want to understand these channels in the ice.

Alan Robertson
March 15, 2016 4:39 am

We already know what happens when vast areas of Antarctic ice shelf break off and float away from their grounding points.The land- based glacier which has been forcing the ice sheet into the sea simply keeps flowing seaward a little faster, until it grounds itself again.
There is nothing new about the phenomenon, we have witnessed it many times before. This study adds a bit to our knowledge about ocean currents below the ice, but the rest of the paper does nothing but add talking points to satisfy a fear- based agenda of the grant paymasters.

mikebartnz
Reply to  Alan Robertson
March 16, 2016 1:13 am

Many years ago there was a calving of ice that was the equivalent length of the distance of going from Wellington to Wanganui in New Zealand and width wise wouldn’t have fitted through the Cook Straight.
It is perfectly normal and not extraordinary.

March 15, 2016 5:03 am

Well this is exciting news from the forefront of scientific research. (sarc)
So, glaciologists now have 100 names for kinds of melting.
It’s not really proper science though is it? Just coming up with new names for the various complex processes involved in the melting or break-up of the terminal of ocean-bound glaciers.
Useless information really.
I mean, what are we going to ever do with this knowledge about upside down melt-river things?
And after all this we still don’t know if Antarctica is currently gaining ice mass or losing ice mass.
Maybe we should stop all this feminist glaciology and concentrate on validating (or invalidating) the GIA’s.
Or trying to figure out why we have record sea ice in this “warming world”.
And maybe NASA needs to intentionally employ some people who are willing to question the institutionalized group-think, playing to the media and rent seeking.

Chris
Reply to  indefatigablefrog
March 15, 2016 8:36 am

Specifically why is it not proper science?

Alan Robertson
Reply to  Chris
March 15, 2016 10:29 am

Specifically, because of the inclusion of all of the political fear mongering.

Chris
Reply to  Chris
March 16, 2016 12:31 am

The validity of the underlying science is not undercut by how the results are communicated. And if a scientist thinks sea levels are going to rise by 1 meter or more over the next century, how do you think they should communicate that? It’s a pretty big deal if true.

mikebartnz
Reply to  Chris
March 16, 2016 1:06 am

It is not proper science because it shows no relation to what has happened in the previous past but just enlightens us as to what is happening now (that part is science) so nothing can be estimated as to what is going to happen in the future because of the lack of data.
Quote *It’s a pretty big deal if true.*. That is the problem as there is just too much guessing as to whether the sea levels are going to rise by a metre or more and because the Antarctic is actually gaining ice it is looking less true.

Reply to  Chris
March 16, 2016 1:36 am

“Science is a systematic enterprise that creates, builds and organizes knowledge in the form of testable explanations and predictions about the universe.” wikipedia definition.
How does this kind of “looking and naming” exercise fulfill that definition?
If I studied the formation of cracks in the surface of a cooling quiche, then would that be a worthy scientific enterprise? Would I be able to name the processes witnessed and call it science? Surely, it would just constitute pointless analysis of what happens to happen when quiche cools.
And the study of the various attributes of glaciers should really be regarded as a sub-discipline of Geography or Environmental Studies.
Alas – everyone is now a scientist.
No predictions and no testing.
But they are all busy doing “science”.
At least, so they claim.

mikebartnz
Reply to  indefatigablefrog
March 15, 2016 6:09 pm

Recent reports show that the Antarctic has been gaining ice and for some time. Not just sea ice either.

Resourceguy
March 15, 2016 5:15 am

Channeling for dollars, just like Jerry Brown

The Original Mike M
March 15, 2016 5:32 am

They’ve already identified high geothermal activity melting glaciers in West Antarctica so could there not also be high geothermal activity on the sea floor just off the coast of West Antarctica heating the water?

March 15, 2016 5:38 am

Haven’t read the article but might they be thinking of this:
http://www-das.uwyo.edu/~geerts/cwx/notes/chap11/ant_wave.html

Dave in Canmore
March 15, 2016 5:49 am

“Ice shelves are really vulnerable parts of the ice sheet, because climate change hits them from above and below,” said NSIDC scientist and study co-author Ted Scambos.”
Not getting warmer above: ftp://ftp.ssmi.com/msu/graphics/tlt/plots/rss_ts_channel_tlt_southern%20polar_land_and_sea_v03_3.png
Not getting warmer below:comment image
Ted Scambos’s sensational statement bears little resemblance to the real world. These are not scientists, they are propaganda merchants telling fibs on the taxpayers dime. This is what you get when there is too much money available and no one looking after the purse strings. I’m predicting that it will be America’s crushing debt that finally ends the CAGW nonsense. I suppose in that sense, Obama has brought the end of CAGW a little closer by adding 10 trillion to the debt.

belousov
Reply to  Dave in Canmore
March 15, 2016 8:20 am

+1

Roney Long
March 15, 2016 5:58 am

Can someone calculate the energy mass-balance in this ice into water scenario? Warm water melts ice and nothing else happens? When I put ice into a glass with liquid (OK, sometimes even with a key ingredient of anti-freeze in it) the liquid gets colder until an equilibrium exists. Does the seawater get colder and push us toward an ice age?

george e. smith
Reply to  Roney Long
March 15, 2016 1:02 pm

Mix equal masses (m) of 80 deg. C McDonalds hot coffee water and zero deg. C refrigerator ice in a thermos flask so heat can’t leave or enter, and you will end up with 2m grams of zero deg. C “ice water”.
G

dp
March 15, 2016 6:08 am

What would really be profound is if they discovered this process were not happening. It would suggest new physics at a minimum. Next we will learn that Arctic ice melts from below. Shazam! I’m kind of wondering if recent reports of expected processes are being floated to justify grant money spending. They’re certainly not getting anywhere proving the CAGW hypothesis, and revelations like this inverse “river bed” is a wicked cool way to keep the flag flying. Oh, and skeery, too.

John F. Hultquist
Reply to  dp
March 15, 2016 8:19 am

… said Karen Alley, a Ph.D. student in CU-Boulder’s Department of Geological Sciences and lead author of an analysis published today in Nature Geoscience …
Students need to eat and have a warm place to sleep. Without students the need for professors goes away. Administrators need both. Funding agencies need …
It is like a chain, although the links in this case are other people’s money.

Joe Crawford
Reply to  John F. Hultquist
March 15, 2016 1:18 pm

“Without students the need for professors goes away.” Might do now but only after years of professorial workload per student decreasing (e.g., student faculty ratios now on the order of 10:1 down to 8:1 with student staff ratios as low as 3:1). Wow, its a good thing our tax money now pays for most of it! /sark

george e. smith
Reply to  John F. Hultquist
March 16, 2016 4:29 pm

Well our Commie buddy, Bernie Sanders is going to reduce the cost of a college education to zero, so at that point there won’t be any money coming in to pay these professors who advise their gullible students to study something that nobody else ever studied before. That way, their PhD thesis will be the most cited paper in the whole field.
Hint to grad students. The fact that there isn’t already a body of papers on this subject is perhaps a clue, that there is nobody willing to pay you a dime for anything you find out about this subject.
You are the world’s leading authority on this subject, and likely the only person with any interest in it at all.
G

JohnKnight
Reply to  dp
March 15, 2016 3:54 pm

dp,
“What would really be profound is if they discovered this process were not happening.”
That’s what I thought . . Like; What the hell did you think would happen under those circumstances? Give me just one alternative, please . .

chris moffatt
March 15, 2016 6:19 am

Oh noes! It’s feasible that it’s worse than we thought. But we don’t know so please send more munny so we can study this again.

Peter Foster
March 15, 2016 6:24 am

They say upside down rivers of warm fresh water ? really !
From where comes the fresh water ? Antarctic sea surface temperatures in McMurdo Sound are around -1.96°C glacial ice melts at 0°C, the atmospheric temperatures almost never get above 0. So from where (other than volcanic activity under the West Antarctic ice) comes the warmth to melt the glacial ice.
When the sea ice forms it excludes much of its salt which then increases the salinity of the very cold water under the ice. This then sinks to form the thermo-haline currents. When the sea ice melts it will initially create a layer of less dense sea water but a long long way from being fresh – perhaps the researchers could try drinking it !!! . When working on the sea ice years ago we had to melt ice from icebergs for drinking. You sure as hell cannot drink melted sea ice, so it is not going to be fresh enough to raise its freezing point to 0 or above.
Did they actually measure the sea temperatures under the ice or merely assume they were warm.?
Course not, that info came from models -. enough said

Peter Lord
March 15, 2016 6:27 am

Where is the hot water coming from? A rhetorical question really. Wouldn’t have any connection with the volcanic activity detected underneath the ice last year in western Antarctica I suppose.

Mike Bromley the Kurd
March 15, 2016 6:30 am

They’re like spoilt children. The ice is growing, but we have to find a way to make that into a scary scenario.

David Chappell
March 15, 2016 6:38 am

“…the study points to the need for more observation and study of the features.”
Ms Alley setting herself up for a nice fat grant when she gets her PhD?

Kiwikid
March 15, 2016 6:46 am

Pamela thanks for the link very interesting.
The article above is also of great benefit and interest and will provide a better long term understanding. I see nothing alarmist about it, just more scientific study for better understanding what actually occurs under the thick ice sheets.

Neo
March 15, 2016 6:46 am

So, what happened to the post-colonial feminist viewpoint.
These “pinning points” sure sound a lot like some sort of phalanx symbol .. or is the “glacier sliding out” some “rape culture” illusion ?

Caleb
March 15, 2016 6:52 am

I like the ideas, but the weak point is that the “pinning points” are really holding all that much ice back. The power of a glacier is enormous, and these are humongous. A “pinning point” is something they will just plow aside, or grind over.

Don Easterbrook
March 15, 2016 7:02 am

Even NASA admits that the Antarctic ice sheet is growing and the increase in total ice volume is causing lowering of sea level. Studies have recently shown a coincidence of high geothermal heat flow beneath the same parts of the much smaller West Antarctic ice sheet that are supposed to be warmed by sea water.
Most of the West Antarctic ice sheet is thicker than the depth below sea level so it will remain grounded and the two tiny outlet glaciers attracting so much attention aren’t going to have any significant effect on the overall ice sheet (and certainly none at all on 90% of Antarctic ice contained in the East Antarctic ice sheet).
From time to time, large chunks of ice shelves break off and float away (with great predictions of coming doom by alarmists and the news media), but history has shown that in a few years they are back again.

John F. Hultquist
Reply to  Don Easterbrook
March 15, 2016 8:22 am

Weeds in my garden and ice in Antarctica — who knew?

Chris
Reply to  Don Easterbrook
March 15, 2016 8:38 am

Do you have supporting links for the statement that total ice volume is growing in Antarctica?

Alan Robertson
Reply to  Chris
March 15, 2016 9:25 am

Do you have a search engine?

Chris
Reply to  Chris
March 15, 2016 9:42 pm

Alan, as a matter of fact I do. Mine shows that the volume of Antarctic ice is shrinking, not growing.http://www.reuters.com/article/us-science-antarctic-idUSKBN0MM2J720150326

mikebartnz
Reply to  Chris
March 15, 2016 10:15 pm

Chris the link you give supporting the ice shrinking is over a year old but there have been two recent reports of it growing and one them by one of those US agencies which tries to promote the whole CAGW theory which surprised me.

Alan Robertson
Reply to  Chris
March 15, 2016 10:25 pm

Pity that you couldn’t find the sea ice page. you won’t find much evidence there for declining Antarctic ice. Your linked article even stated that there isn’t enough evidence to link climate change with Antarctic sea ice change. Nice try, though.
http://wattsupwiththat.com/reference-pages/sea-ice-page/

Chris
Reply to  Chris
March 16, 2016 12:37 am

Pity that you don’t know the difference between ice extent and ice volume. The sea ice page doesn’t cover Antarctic ice volume. Nice try, though.

Chris
Reply to  Chris
March 16, 2016 12:39 am

Oh, and Easterbrook’s point was that Antarctic ice volume was growing. That was what I was disputing. Why are you bringing in a discussion of the cause of the decline? That’s not what we were discussing. Nice try at deflection, though.

Don Easterbrook
Reply to  Chris
March 16, 2016 12:12 pm
Slacko
Reply to  Chris
March 16, 2016 4:34 pm

Chris. reuters.com ?? The best you could find was MSM ??

seaice1
Reply to  Chris
March 17, 2016 2:40 am

The key paper is by Jay Zwally et al., referred to here:
http://www.nature.com/news/gains-in-antarctic-ice-might-offset-losses-1.18486
This one study does say that ice mass is increasing. Other studies say it is shrinking. All studies say that the rate of ice flow is increasing. The Zwally paper says that this is more than counter-balanced by increasing precipitation due to warmer waters. Zwally also says that if current trends continue, the ice will soon start losing mass.
If Zwally is right (and that is not certain), sea contributiuons to sea level rise from elswhere is occuring faster than we thought. If the contribution from the Antarctic is actually negative, the measured rise must be coming from somewhere else.

Russell
March 15, 2016 7:19 am
Sam
March 15, 2016 7:56 am

Absolutism to the point of the absurd. This one woman
just discovered underside scouring of ice plates by warm water. It’s been known since lakes and bays showed the same effect from the beginning of time,
and the source of the energy is known to be natural, there’s no manmade heating of oceans there.
The oceans are miles deep. The temperature of the planet = warmer the deeper in crust/outer mantle/inner mantle one goes. Ocean water is a tremendous heatsink and saps energy out of the surface of the earth at a gigantic rate by virtue of the two being affixed in tight thermal bond with each other.
It’s why water is to this day the preferred liquid to place alongside hot cylinders of an internal combustion engine.
If you have already gotten yourself somehow convinced mankind can even make oceanic temperatures blip I’m sure it took a lot of work. You can spam all the fake logic you want, but there’s one reason, and one reason only, the planet surface isn’t much, MUCH hotter:
the water soaking the surface of the planet pulled into liquid-to-solid level thermal conduction,
the air hastening the cooling of what water’s not sitting on cooling.
And mankind couldn’t even make a thermometer blip in that energy relationship.
At any given moment the earth itself is generating temperature from within.
Sunlight is delivering energy to the surface,
and mankind is hardly a flea on a freight train in oceanic warming, sandwiched between those two.

seaice1
March 15, 2016 at 6:31 am
No. The relative heat capacity of air and water does not imply that this is a natural occuring process. It implies absolutely nothing about the origins of the process.

TonyN
March 15, 2016 8:04 am

“…….While no ice shelves have completely disintegrated due to carving by basal channels, the study points to the need for more observation and study ”
But really, guys, what more needs to be known about how sea-ice melts from the bottom?
Clearly this is just another instance of ‘Send Money Or The Globe Gets It’ ?

belousov
March 15, 2016 8:19 am

This is a good example of the logical fallacy “we’ve just looked for and found this for the first time so it must have only just started happening”.

FJ Shepherd
March 15, 2016 8:41 am

If ice shelves were not eroded in Antarctica through natural processes, these shelves would have steadily grown and extended north and hit South America, Africa and Australia long ago. I am not too sure what this paper is really suggesting, but to discount that ice shelf erosion is not a natural process seems to indicate that those who authored this paper lack a basic intellectual capacity to reason. Or, I suppose they could be climate alarmists and this would explain such a lack.

Reply to  FJ Shepherd
March 15, 2016 9:12 am

And the rate of growth is nothing short of remarkable: Ross Ice Shelf in the Antarctic expands with the average speed 2.5 meters a day!

Betapug
March 15, 2016 8:41 am

The adjective “vulnerable” needs to be much more liberally sprinkled onto the ice in order to float further financing in my opinion.

RWturner
March 15, 2016 10:42 am

This is what warming looks like after drinking that spiked green kool-aid.comment image

Toneb
Reply to  RWturner
March 15, 2016 1:15 pm

Can I refer you to this from the article….
“The features form as buoyant plumes of warm and fresh water rise and flow along the underside of an ice shelf, carving channels much like upside-down rivers. The channels can be tens of miles long, and up to 800 feet “deep.””
In other words, it is waters at depth that are the the cause of the melt channels and not surface waters.
See…
http://www.cesm.ucar.edu/events/ws.2015/presentations/crosswg/deser.pdf
and
http://www.atmosp.physics.utoronto.ca/SPARC/pdfs/26%20Tue/Session%202/2_2_Heywood.pdf

Reply to  RWturner
March 15, 2016 3:58 pm

RWturner,
You have to do it like Toneb, and look at it upside down…

Chris Hanley
March 15, 2016 12:35 pm

“It’s feasible that increasing ocean temperatures around Antarctica could continue to erode ice shelves from below …”.
============================
Diagram showing circum-Antarctic ocean temperatures at selected depths, using Argo-data:
http://www.climate4you.com/images/ArgoCircumAntarcticSince200401%2055S-65S.gif

Robert
March 15, 2016 2:15 pm

Seen a report on an Aussie warmist show “catalyst” on the Antarctic ice shelf melt a while back ,when the camera was panning the shoreline they passed a polar bear WUWT .

Alan Robertson
Reply to  Robert
March 15, 2016 4:19 pm

That was a member of the Sea Leopard and Polar Bear Co-evolution Alliance. You can always spot them by their “Coexist” and “Bernie” bumper stickers.

TA
March 15, 2016 4:08 pm

From the study: ““Ice shelves are really vulnerable parts of the ice sheet, because climate change hits them from above and below,” said NSIDC scientist and study co-author Ted Scambos.”
Is there any evidence that human-caused global warming/climate change has caused an increase in the water temperature around the Antarctic continent? Or in the temperture of the air above it?
I think these scientists are assuming too much.

Gary Pearse
March 15, 2016 5:20 pm

Am I mistaken in thinking that women climate scientists, who used to be a small minority, are popping up in ever larger numbers? WUWT? I guess the feminist glaciologists are working faster than I thought.
http://wattsupwiththat.com/?s=gender+based+glaciology

Gregory
March 15, 2016 7:37 pm

This is neither here nor there regarding the claims of the article, but I just had the privilege of spending three weeks in Antarctica and one day we passed through what seemed like an iceberg superhighway, with a chain of huge tabular icebergs, some larger than city blocks, extending to the horizon. Photos don’t do justice to the experience of seeing these in real life. This photo was taken from Gourdin Island, so I believe these icebergs probably came from the Weddell ice shelf.
http://i.imgur.com/BYcwuE1.jpg

papiertigre
March 15, 2016 9:30 pm

Well I should hope so. If the ice shelf keeps piling up like it has been, those poor pitiful barely surviving Adelie penguins will never make it back to the ocean.

March 15, 2016 10:56 pm

In summer 2009, the Norwegians directly measured water temperature under the Fimbul icesheet and found it was about two degrees C colder than the ice sheet freezing point. (also in 2005 & 2008).
In a University of Tasmania thing at ‘The Conversation’ entitled: Tipping point: how we predict when Antarctica’s melting ice sheets will flood the seas I commented (Here: https://theconversation.com/tipping-point-how-we-predict-when-antarcticas-melting-ice-sheets-will-flood-the-seas-56125 )
“I notice that the authors assert; “Melting beneath ice shelves is the main source of Antarctic ice loss” and [they] link to a paper. However, there are no seawater temperature data in that paper.
In summer 2009 the Norwegian Polar Institute bored through the Fimbul ice-shelf and found seawater temperatures under the ice at close to the freezing point of seawater (salinity dependent). That is about two degrees colder than the freezing point of freshwater (ice-shelves) and it was summertime. They also reported:
“The temperatures are very similar to temperature data collected by elephant seals in 2008 and by British Antarctic Survey using an autosub below the ice shelf in 2005.”
To confirm that “Melting beneath ice shelves is the main source of Antarctic ice loss” and to assess whether it is on the increase, it would be necessary to have seasonal time-series data which apart from being logistically difficult would require time-travel into the past. See:
http://www.npolar.no/en/news/2009/2009-12-11-ocean-beneath-fimbul-ice-shelf-is-cold.html”

Mark
March 16, 2016 1:31 am

List of and locations including satellite photos and eruption details (follow the links) of Volcanoes in Antarctica.
I hate using Wiki links grrr
https://en.wikipedia.org/wiki/List_of_volcanoes_in_Antarctica

Mark
March 16, 2016 1:34 am

Antarctica sees earthquakes too, they had some in 2010 and March 2011.
isn’t there also at least one active Volcano under the western ice sheet?

Mark
March 16, 2016 1:36 am

“Two earthquake swarms struck beneath the researchers’ feet in January 2010 and March 2011, near the Executive Committee Range in the Marie Byrd Land region of the continent. As the researchers later discovered, the tremors — called deep, long-period earthquakes (DLPs) — were nearly identical to DLPs detected under active volcanoes in Alaska and Washington. The swarms were 15 to 25 miles (25 to 40 kilometers) below the surface.”
Active Volcano Discovered Under Antarctic Ice Sheet
http://www.livescience.com/41262-west-antarctica-new-volcano-discovered.html
Earthquakes deep below West Antarctica reveal an active volcano hidden beneath the massive ice sheet, researchers said today (Nov. 17) in a study published in the journal Nature Geoscience.

tadchem
March 16, 2016 10:45 am

They do not quantify the word ‘warm’ when discussing Antarctic Sea water. The Antarctic Oceans typically runs about -2° C due to the salinity of the salt water, but would need to warm above 0°C to melt the fresh water ice that forms the ice shelves. The Antarctic Circumpolar Current, which extends from the surface to the sea floor in a circle around the continent, effectively blocks the warmer waters of the Atlantic, Pacific, and Indian oceans from ever reaching Antarctica.

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