East Antarctica melting could be explained by oceanic gateways

March 16, 2015
Landscape beneath Totten Glacier. The orange arrows indicate gateways under the ice where warm water could be entering. The red lines indicate a three-mile-wide trough where the warm water could be pooling below the ice. Credit: Jamin Greenbaum

Researchers at The University of Texas at Austin's Institute for Geophysics (UTIG) in the Jackson School of Geosciences have discovered two seafloor gateways that could allow warm ocean water to reach the base of Totten Glacier, East Antarctica's largest and most rapidly thinning glacier. The discovery, reported in the March 16 edition of the journal Nature Geoscience, probably explains the glacier's extreme thinning and raises concerns about how it will affect sea level rise.

Totten Glacier is East Antarctica's largest outlet of to the ocean and has been thinning rapidly for many years. Although deep, warm water has been observed seaward of the glacier, until now there was no evidence that it could compromise coastal ice. The result is of global importance because the ice flowing through Totten Glacier alone is sufficient to raise global sea level by at least 11 feet, equivalent to the contribution of the West Antarctic Ice Sheet if it were to completely collapse.

"We now know there are avenues for the warmest waters in East Antarctica to access the most sensitive areas of Totten Glacier," said lead author Jamin Greenbaum, a UTIG Ph.D. candidate.

The ice loss to the ocean may soon be irreversible unless atmospheric and oceanic conditions change so that snowfall outpaces coastal melting. The potential for irreversible ice loss is due to the broadly deepening shape of Totten Glacier's catchment, the large collection of ice and snow that flows from a deep interior basin to the coastline.

"The catchment of Totten Glacier is covered by nearly 2½ miles of ice, filling a sub-ice basin reaching depths of at least one mile below sea level," said UTIG researcher Donald Blankenship.

The Totten Glacier catchment (blue outline) is a collection basin for ice and snow that flows through the glacier. It's estimated to contain enough material to raise sea levels by at least 11 feet. Credit: Australian Antarctic Division

Greenbaum and Blankenship collaborated with an international team from the United States, Australia, the United Kingdom and France.

Because much of the California-sized interior basin lies below , its overlying thicker ice is susceptible to rapid loss if warm ocean currents sufficiently thin coastal ice. Given that previous work has shown that the basin has drained its ice to the ocean and filled again many times in the past, this study uncovers a means for how that process may be starting again.

"We've basically shown that the submarine basins of East Antarctica have similar configurations and coastal vulnerabilities to the submarine basins of West Antarctica that we're so worried about, and that warm ocean water, which is having a huge impact in West Antarctica, is affecting East Antarctica, as well," Blankenship said.

The deeper of the two gateways identified in the study is a three-mile-wide seafloor valley extending from the ocean to beneath Totten Glacier in an area not previously known to be floating. Identifying the valley was unexpected because satellite analyses conducted by other teams had indicated the ice above it was resting on solid ground. Special analysis of ice-penetrating radar data shows the bottom of the ice over the valley is smoother and brighter than elsewhere in the area—tell-tale signs that the ice is floating and being eroded by the ocean.

A group shot of the research team in Antarctica. Credit: Gregory Ng

"Now we know the ocean is melting ice in an area of the glacier that we thought was totally cut off before," Greenbaum said. "Knowing this will improve predictions of ice melt and the timing of future glacier retreat."

In some areas of the ocean surrounding Antarctica, warm water can be found below cooler water if it is saltier and, therefore, heavier than the shallower water. As a result, seafloor valleys that connect this deep, to the coast can especially compromise , a process previously known to be occurring along the coast of the West Antarctic Ice Sheet. Although glaciers in West Antarctica have received more attention in previous Antarctic studies, this work shows that similar processes are underway in East Antarctica where there is also the possibility for retreat into an interior basin. As in the West Antarctic Ice Sheet, complete collapse of the Totten Glacier catchment may take many centuries, although the timing of retreat in both places is the subject of intensive research.

The UTIG team collected the data during five Antarctic field campaigns using aircraft loaded with equipment to analyze the ice and seafloor in regions that even icebreakers are unable to reach. The airplane was outfitted with radar that can measure ice several miles thick, lasers to measure the shape and elevation of the ice surface, and equipment that senses the Earth's gravity and magnetic field strengths, which are used to infer seafloor shape.

The data for this study were gathered as part of the UTIG-led ICECAP (International Collaboration for Exploration of the Cryosphere through Aerogeophysical Profiling) project with support from the U.K.'s Natural Environment Research Council, the U.S. National Science Foundation, the Australian Antarctic Division, as well as NASA's Operation IceBridge, the G. Unger Vetlesen Foundation, and the University of Texas at Austin's Jackson School of Geosciences. The ICECAP aircraft was operated under contract to the University of Texas Institute for Geophysics by Kenn Borek Air LTD., Calgary, Alberta, Canada.

Explore further: Warm ocean melting East Antarctica's largest glacier

More information: Ocean access to a cavity beneath Totten Glacier in East Antarctica, Nature Geoscience, DOI: 10.1038/ngeo2388

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31 comments

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pugphan
1.7 / 5 (6) Mar 16, 2015
Ahh so this global warming at work, uh. smokersodysseycom
quickbme
4.1 / 5 (13) Mar 16, 2015
Bad news for coastal cities. Bad news for AGW deniers/skeptics. Basically just bad news.
Wake
1.4 / 5 (11) Mar 16, 2015
The Antarctic is the driest desert in the world. Abnormal effects from anything including tectonic and volcanic effects can cause effects on the Antarctic continent that would take centuries for normal weather to repair.

To point out these effects as if they were caused by a known cause is something less than "scientific". In fact it is something less than sane.
jediknight190501
1.5 / 5 (8) Mar 16, 2015
Well, we'll see what happens. I'm not worrying about it. It is what it is. Nothing can be done about it, so why wring your hands over it?
thermodynamics
4.6 / 5 (11) Mar 16, 2015
Well, we'll see what happens. I'm not worrying about it. It is what it is. Nothing can be done about it, so why wring your hands over it?


Jedi: Why do you think nothing can be done about it? There has been progress in renewable resources, as well as progress in carbon capture and storage. That has been over the past decade with very limited government resources devoted to it. If this was recognized as a problem to be solved and if incentives were put in place, the utilities could solve this issue using existing technology. If there was more research dedicated to lowering the rate of CO2 accumulation in the biosphere we could stop this in its tracks. That is a matter of political will, not technology.

For a technology summary see:

http://www.netl.d...rch/coal

http://energy.gov...e-energy

quickbme
4 / 5 (12) Mar 16, 2015
Wake, you don't give science much credit. It has been firmly established that the majority of melt in Antarctica is due to the warming ocean waters,,,and the waters aren't being warmed by geothermal activity.
Maggnus
4.2 / 5 (10) Mar 16, 2015
Wake, you don't give science much credit. It has been firmly established that the majority of melt in Antarctica is due to the warming ocean waters,,,and the waters aren't being warmed by geothermal activity.


Wake doesn't understand science.
tmalthus2010
1 / 5 (9) Mar 16, 2015
Maybe they ought to check for a humongous thermally active volcanic region under the ice, like the one they found the last time they had similar concerns on the other side of the continent.
Maggnus
4.6 / 5 (9) Mar 16, 2015
Maybe they ought to check for a humongous thermally active volcanic region under the ice, like the one they found the last time they had similar concerns on the other side of the continent.


1. They didn't find any such "humongous thermally active region" despite what some of the denier blogs say.
2. Maybe they have already checked for the cause. Oh look:
We've basically shown that the submarine basins of East Antarctica have similar configurations and coastal vulnerabilities to the submarine basins of West Antarctica that we're so worried about, and that warm ocean water, which is having a huge impact in West Antarctica, is affecting East Antarctica, as well," Blankenship said.

3. The "other side of the continent" is melting due to warming ocean waters as well: http://www.jpl.na...2014-148

Maybe you aught to read more and type less.
fourinfinities
1 / 5 (6) Mar 16, 2015
Oceanic gateways.
For once, it's not global warming...
zz5555
4.4 / 5 (7) Mar 16, 2015
Oceanic gateways.
For once, it's not global warming...

Well, it is if you read the article.
ubavontuba
1 / 5 (5) Mar 17, 2015
East Antarctica melting could be explained by oceanic gateways
More AGWite desperation. Now they will anxiously bow to any wild speculation that comes along, simply because the truth is just too painfully obvious for them to accept.

TRUTH: Cooling for more than 18 years:

http://woodfortre....1/trend

Vietvet
4.3 / 5 (8) Mar 17, 2015
East Antarctica melting could be explained by oceanic gateways
More AGWite desperation. Now they will anxiously bow to any wild speculation that comes along, simply because the truth is just too painfully obvious for them to accept.

TRUTH: Cooling for more than 18 years:

http://woodfortre....1/trend



@ubavontuba

You're not dumb but I can't understand why you so persistently insist on ignoring all the evidence for AGW and cherry pick woefully weak arguments against it.
quickbme
4.1 / 5 (9) Mar 17, 2015
ubavontuba is desperately looking for data which match his ideology.
quickbme
3.7 / 5 (6) Mar 17, 2015
ubavontuba is desperately looking for data which match his ideology.
ubavontuba
1 / 5 (4) Mar 17, 2015
@Vietvet
You're not dumb but I can't understand why you so persistently insist on ignoring all the evidence for AGW and cherry pick woefully weak arguments against it.
Thanks for the backhanded compliment. I don't think you're particularly dumb either ...which makes me wonder; why do you buy into it?

You accuse me of cherry picking, but ever since temperatures refused to cooperate, that's all AGWite scientists do. First, it's the heat is hiding in the Arctic, then it's the heat is hiding in Africa, then it's volcanoes are slowing warming, then the stadium wave, then the ocean, then the Arctic again, ad infinitum.

This isn't evidence of anything, other than regional climate variation.

So what evidence are you talking about?

ubavontuba
1 / 5 (4) Mar 20, 2015
ubavontuba is desperately looking for data which match his ideology.
Hmm... it appears quickbme and Vietvet don't have any data to back up their ideology, all of a sudden.
Vietvet
4.3 / 5 (6) Mar 20, 2015
@ubavontuba

Responding to you is a fools errand because already reject the massive amount of evidence for AGW and cling to lie that there hasn't been any recent warming.

I've never read a study stating the affects of AGW would be homogeneous. To the contrary, all projections I've read point to variations among regions and that is what is being observed.

https://scholar.g...as_vis=1

http://www.ncdc.noaa.gov/sotc/
Mike_Massen
3.7 / 5 (6) Mar 20, 2015
ubavontuba focusing on Weather
TRUTH: Cooling for more than 18 years:
http://woodfortre....1/trend
NOT true.
I can also focus on Weather but, its not climate is it yet my link shows even MORE recent warming !
http://woodfortre....1/trend

Of course, so u don't appear completely dis-ingenuous trying to skew the stats on climate u COULD be smarter & use the accepted climate period of 30yrs:-
http://woodfortre....1/trend

Focusing on Weather ubavontuba, just makes U look stupid !

Any highschool student KNOWS that with noisey data you can pick any arbitrary period but, are you claiming ignorance of high school statistics, surely not - or are you paid to sell your integrity ?

Weather is less than 30 yrs - do u get it now ?

Climate is acknowledged as 30yrs - can u under_stand ?

Integrity ubavontuba !

Where is it ?
ubavontuba
1 / 5 (4) Mar 21, 2015
@Vietvet
Responding to you is a fools errand because already reject the massive amount of evidence for AGW and cling to lie that there hasn't been any recent warming.
How is it a lie when it's an empirically documented fact?

I've never read a study stating the affects of AGW would be homogeneous.
It's in the very definition?

To the contrary, all projections I've read point to variations among regions and that is what is being observed.
How is that any different than not global warming?

https://scholar.g...as_vis=1

http://www.ncdc.noaa.gov/sotc/
Oh, I get it. So to prove "global warming" you're intent is to ignore the word "global" altogether?

So what is it you are not understanding about the word g-l-o-b-a-l?

ubavontuba
1 / 5 (4) Mar 21, 2015
So Vietvet rates my post a "1," but doesn't have the balls to support his fallacious arguments. It appears, therefore, I was wrong. Vietvet apparently is particularly dumb.

Mike_Massen
3.9 / 5 (7) Mar 21, 2015
ubavontuba missed the point & offered weather
]How is it a lie when it's an http://woodfortre...1/trend?
empirically documented fact
Indeed, its documented that anything less than 30yrs is considered weather. But of course you already knew this, so posting weather when the point is to focus on climate just shows u up :-(

I can also focus on Weather but, its not climate is it yet my link shows even MORE recent warming !
http://woodfortre....1/trend

The correct terms of reference, of course, as any educated person knows is to focus on climate & not weather, as:-
http://woodfortre...85/trend

Which matches rise re weather, funny that, showing recent warming AND average warming, which trounces a cherry picked weather period & accounts for denialist warning...

http://www.remss....eratures
Mike_Massen
3.9 / 5 (7) Mar 21, 2015
Vietvet observed re ubavontuba's failure again
@ubavontuba
You're not dumb but I can't understand why you so persistently insist on ignoring all the evidence for AGW and cherry pick woefully weak arguments against it.
Good question, we see ubavontuba focuses ONLY on weather periods despite FACT he knows well climate of 30yrs+ is the key indicator shows ubavontuba has sold his integrity, the evidence is he avoids climate & barbs old links re ice and/or misinterprets them, so sad

ubavontuba, caught again, selling itself, whats that called ?

Geesh, almost as bad as water_prophet, makes claims that cannot be supported & just like water_prophet ubavontuba doesnt understand specific/latent heat & just why ice is so very important as a buffer & can't understand why any loss of ice is a significant change in enthalpy.

https://en.wikipe...Enthalpy

Education is so important ubavontuba, especially physics, in all the time here u could have graduated :-(
Vietvet
4 / 5 (7) Mar 21, 2015
@ubuvontuba

So Vietvet rates my post a "1," but doesn't have the balls to support his fallacious arguments. It appears, therefore, I was wrong. Vietvet apparently is particularly dumb.



What could be dumber than not understanding "average"?
Vietvet
4 / 5 (7) Mar 21, 2015
@ubavontuba

You linked a graph and so will I, only mine isn't cherry picked.

http://www.skepti...php?g=47
Captain Stumpy
4.3 / 5 (6) Mar 21, 2015
TRUTH: Cooling for more than 18 years:

http://woodfortre....1/trend
@uba
a cherry picked graph... AND you are wrong
http://woodfortre....1/trend

http://woodfortre...o:2015.1

However, with sharp tools comes great responsibility... Please read the notes on things to beware of - and in particular on the problems with short, cherry-picked trends. Remember that the signals we are dealing with are very, very noisy, and it's easy to get misled - or worse, still to mislead others.
this quote was put on the site for cherry-picking deniers like you, uba
The site YOU linked to
the site which also shows that YOU ARE WRONG
Captain Stumpy
4.4 / 5 (7) Mar 21, 2015
How is it a lie when it's an empirically documented fact?
No, it is a cherry picked graph with cherry picked points of interest which you select to demonstrate your lack of scientific acumen: choose a 30 year trend (by simply adding two years) and your whole graph changes to a warming trend (which i did above)

OR
select the global averages, and you fail AGAIN
OR
select everything & compare CRUTEM 3 & 4
http://www.woodfo...60/trend
IOW - read the warning about cherry picking (i quoted that above from your own linked site just for you)
...you're intent is to ignore the word "global" altogether?
but YOU are ignoring the global temps with your cherry picked graph too

http://www.ploson...tion=PDF
Captain Stumpy
4.3 / 5 (6) Mar 21, 2015
ubavontuba is desperately looking for data which match his ideology.
Hmm... it appears quickbme and Vietvet don't have any data to back up their ideology, all of a sudden.
and why would anyone want to respond when all you will do is ignore ANY empirical evidence or scientific studies which do not match your own ideology, faith, belief or delusional interpretation of the world?
http://www.ploson...tion=PDF

this goes right back to your arguments against the studies i linked
you CLAIM to have refuted them... except that there are NO retractions nor are there ANY changes

that is a simple way of proving that not only do you NOT know WTF you are talking about, but that you are biased against the science due to a delusional/conspiratorial belief

want to change how the world sees AGW?
publish a study and refute the science that is already proven

otherwise you are only trolling
ubavontuba
1 / 5 (4) Mar 21, 2015
@Vietvet
What could be dumber than not understanding "average"?
Nothing. So why do you have such a problem with it? Why do you generally refer to regional climate issues when discussing G-L-O-B-A-L warming?

You linked a graph and so will I, only mine isn't cherry picked.

http://www.skepti...php?g=47
LOL. Seriously? You claim the stupid step graph from skeptiNOTscience is NOT cherry-picked? You didn't even notice they added an artificial step in the past few years to try to falsely break up the current pause? How is that not cherry-picking?

Vietvet
3.9 / 5 (7) Mar 21, 2015
@ubavontuba

[q

This isn't evidence of anything, other than regional climate variation.

How quickly you forgot that it you were the one that brought "regional climate variation".

I pointed out that all models project variations by regions in GLOBAL warming.

ubavontuba
1 / 5 (4) Mar 21, 2015
@Vietvet
I pointed out that all models project variations by regions in GLOBAL warming.
Again, how is this different from NOT global warming? Do you really think regional climate doesn't vary in a neutral, or cooling, global temperature phase?

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