Bedrock in West Antarctica rising at surprisingly rapid rate

June 21, 2018, The Ohio State University
Antarctica, as seen using Google Earth, and a cut to show the interior of the earth, where the mantle (red and dark red) and the core (yellow) are visible. The Amundsen Sea Embayment is indicated by the red rectangle. On the right, a photo reveals one of the GPS sites in the study. Credit: VR. Barletta, DTU Space at the Technical University of Denmark/Google Earth/Terry Wilson, The Ohio State University

The earth is rising in one part of Antarctica at one of the fastest rates ever recorded, as ice rapidly disappears and weight is lifted off the bedrock, a new international study has found.

The findings, reported in the journal Science, have surprising and positive implications for the survival of the West Antarctic Ice Sheet (WAIS), which scientists had previously thought could be doomed because of the effects of climate change.

The unexpectedly fast rate of the rising may markedly increase the stability of the against catastrophic collapse due to ice loss, scientists say.

Moreover, the rapid rise of the earth in this area also affects gravity measurements, which implies that up to 10 percent more ice has disappeared in this part of Antarctica than previously assumed.

Researchers led by scientists at The Ohio State University used a series of six GPS stations (part of the POLENET-ANET array) attached to bedrock around the Amundsen Sea Embayment to measure its rise in response to thinning ice.

The "uplift rate" was measured at up to 41 millimeters (1.6 inches) a year, said Terry Wilson, one of the leaders of the study and a professor emeritus of earth sciences at Ohio State.

In contrast, places like Iceland and Alaska, which have what are considered rapid uplift rates, generally are measured rising 20 to 30 millimeters a year.

"The rate of uplift we found is unusual and very surprising. It's a game changer," Wilson said.

And it is only going to get faster. The researchers estimate that in 100 years, uplift rates at the GPS sites will be 2.5 to 3.5 times more rapid than currently observed.

"These results provide an important contribution to our understanding of the dynamics of the Earth's bedrock, along with the thinning of ice in Antarctica. The large amount of water stored in Antarctica has implications for the whole planet," said lead study author Valentina R. Barletta, who started this work at Ohio State and now is a postdoctoral researcher at the National Space Institute (DTU Space) at the Technical University of Denmark.

"The new findings raise the need to improve ice models to get a more precise picture of what will happen in the future."

While modeling studies have shown that bedrock uplift could theoretically protect WAIS from collapse, it was believed that the process would take too long to have practical effects.

"We previously thought uplift would occur over thousands of years at a very slow rate, not enough to have a stabilizing effect on the ice . Our results suggest the stabilizing effect may only take decades," Wilson said.

Wilson said the rapid rise of the bedrock in this part of Antarctica suggests that the geology underneath Antarctica is different from what scientists had previously believed.

Underneath the solid upper layer of Earth is a hotter and more fluid layer of rock called the mantle. Exactly how hot and fluid the mantle is varies across the planet.

The rapid uplift around the Amundsen Sea Embayment suggests that the mantle in this area is hotter and more fluid (or, as scientists say, it has lower viscosity) than expected, according to Barletta.

Barletta ran a variety of computer models using scenarios of ice loss through time in the area to explain how such rapid uplift could be occurring today.

Terry Wilson, professor emeritus of earth sciences at The Ohio State University, assembles a GPS antenna on a monument fixed to bedrock. This GPS unit is at Westhaven Nunatak in the Transantarctic Mountains. Credit: The Polar Earth Observing Network

The results of Barletta's models showed that the GPS findings today could best be explained by having a low-viscosity mantle, Wilson said.

That would mean the bedrock reacts more quickly when the weight of ice is removed—which is exactly what the GPS results showed.

These new measurements of Glacial Isostatic Adjustment (GIA), the scientific term for uplift due to ice sheet unloading, are an important part of a wider story about the fate of the Antarctic ice sheets, said Doug Kowalewski, the Antarctic Earth Sciences program director in the National Science Foundation's Office of Polar Programs (OPP).

"The observed GIA response captured by the POLENET array is an order of magnitude greater than previously thought. The upcoming challenge is to couple the GIA observations with ice-sheet models," Kowalewski said.

"These data will be of great value to the modeling community who examine the complex relationships between GIA, sub-ice shelf ocean circulation, and ultimately, ice sheet stability."

The biggest practical effect of the uplift may be a rare bit of good news for what is happening in this part of Antarctica as a result of climate change, Wilson said.

The West Antarctic Ice Sheet plays a key role in sea level rise. Estimates suggest this ice sheet alone accounts for one-fourth of global sea level rise that can be attributed to disappearing snow and ice.

Some scientists suggest that WAIS may have passed a tipping point in which can no longer be stopped, which could be catastrophic, Wilson said. The glaciers there contain enough water to raise global sea levels up to four feet.

The problem is that much of this area of Antarctica is below sea level. Relatively warm ocean water has flowed in underneath the bottom of the ice sheet, causing thinning and moving the grounding line—where the water, ice and solid earth meet—further inland.

The process seemed unstoppable, Wilson said. "But we found feedbacks that could slow or even stop the process."

One important feedback involves "pinning points—elevated features of the earth rising from the surface below the grounding line that pin the ice sheet to solid earth. These pinning points are going up in response to the uplift of the earth and could prevent further retreat of the ice sheet.

Another feedback is lowering sea levels. Massive ice sheets along the ocean have their own gravitational pull and raise the sea level near them. But as the ice thins and retreats, the gravitational pull lessens and the sea level near the coast goes down.

"The lowering of the , the rising of pinning points and the decrease of the inland slope due to the uplift of the bedrock are all feedbacks that can stabilize the ice sheet," Wilson said.

Other researchers had estimated how much the earth would have to rise to protect WAIS given a range of future climate warming scenarios.

Results of this study estimate that the bedrock at the Pine Island Glacier grounding line (which is part of WAIS) will have risen about 8 meters in 100 years. That is about three times higher than values shown by others to reduce run-away retreat in this area.

"Under many realistic climate models, this should be enough to stabilize the ice sheet," Wilson said.

She said while this study delivers some potentially good news for the Amundsen Sea Embayment, that doesn't mean all is well in Antarctica.

"The physical geography of Antarctica is very complex. We found some potentially positive feedbacks in this area, but other areas could be different and have negative feedbacks instead," she said. Regardless of feedbacks, models suggest that the WAIS will collapse if future global warming is large.

Explore further: New study suggests surprising wrinkle in history of West Antarctic Ice Sheet

More information: V.R. Barletta el al., "Observed rapid bedrock uplift in Amundsen Sea Embayment promotes ice-sheet stability," Science (2018). science.sciencemag.org/cgi/doi … 1126/science.aao1447

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grandpa
1 / 5 (6) Jun 21, 2018
Lions, tigers, and bears, oh my!
etherair
1 / 5 (9) Jun 21, 2018
Ow, this porridge is too hot.
Ew, this porridge is too cold.

Left foot in a bucket of boiling water.
Right foot in a bucket of ice.

Rising land pins underwater ice.
Rising land melts terrestrial ice faster.

The average American has 1.4 siblings.
The rest have one or three for the most part.

Using anecdotes for science is not very functional.
Sample sizes of 'one' do not make a statistic.
Urgelt
5 / 5 (4) Jun 21, 2018
Not sure about this so-called 'silver lining.'

This study tells us two important things about the West Antarctic: 1) loss of ice mass is causing the land there to rise at an unexpectedly-high rate (an unprecedented rate, actually); and 2) molten rock under West Antarctica appears to be less viscous, more fluid than previously appreciated.

So, yeah, maybe as the land rises, melting ice sheets will catch on higher protuberances. Maybe. Eventually.

But the paper didn't look at what these new factors imply about volcanism.

Reducing the ice mass on West Antarctica might lead to an increase in volcanic activity on the subcontinent. How much? I have no idea, but the last thing we need right now is a dozen new volcanoes spewing sulfur and CO2 into the atmosphere and blasting ash around to reduce the albedo of the snow pack.

Could be I'm worrying over nothing. But I'd feel better if vulcanologists were to look over these findings and set about figuring things out.
Surveillance_Egg_Unit
4 / 5 (4) Jun 21, 2018
Not sure about this so-called 'silver lining.'

...the last thing we need right now is a dozen new volcanoes spewing sulfur and CO2 into the atmosphere and blasting ash around to reduce the albedo of the snow pack.

Could be I'm worrying over nothing. But I'd feel better if vulcanologists were to look over these findings and set about figuring things out.


says Urgent

Agreeing with you there. It could become a source of worry for future researchers who will be less surprised than those who tell their story now. Antarctica was once a part of the super-continent, Gondwana where evidence shows that plants (now fossils) grew in the Antarctic under much warmer conditions/weather. As Antarctica broke off and drifted to the South Pole, the few or many volcanoes underlying the new continent would have remained beneath that land mass, unless the "tubes" had broken off from the movement.
grandpa
1 / 5 (4) Jun 21, 2018
Not sure about this so-called 'silver lining.'

This study tells us two important things about the West Antarctic: 1) loss of ice mass is causing the land there to rise at an unexpectedly-high rate (an unprecedented rate, actually); and 2) molten rock under West Antarctica appears to be less viscous, more fluid than previously appreciated.

So, yeah, maybe as the land rises, melting ice sheets will catch on higher protuberances. Maybe. Er and CO2 into the atmosphere and blasting ash around to reduce the albedo of the snow pack.

Could be I'm worrying over nothing. But I'd feel better if vulcanologists were to look over these findings and set about figuring things out.

What will be will be!
Surveillance_Egg_Unit
4 / 5 (4) Jun 22, 2018
Just curious about this, so I consulted Wikipedia for Gondwana.

Australia–Antarctica separation
In the Early Cenozoic Australia was still connected to Antarctica c. 35–40° south of its current location and both continents were largely unglaciated. A rift between the two developed but remained an embayment until the Eocene-Oligocene boundary when the Circumpolar Current developed and the glaciation of Antarctica began.[48]

I would find it very interesting if the whole of Antarctica might be beginning the process of drifting away from its present location as it did from Australia many moons ago, now that the heaviness of the ice field is slowly being lifted from it.

antigoracle
1.7 / 5 (6) Jun 22, 2018
OH NOSE!!!
The West Antarctic, an area of intense geothermal activity, is rising.......So, let's blame GloBULL warming.
LMAO.....Run for the hills Chicken Littles.

Yellowstone.....beginning in 2004, scientists saw the ground above the caldera rise upward at rates as high as 2.8 inches (7 centimeters) a year.

https://news.nati...science/
Whydening Gyre
5 / 5 (3) Jun 22, 2018
Just curious about this, so I consulted Wikipedia for Gondwana.
...
I would find it very interesting if the whole of Antarctica might be beginning the process of drifting away from its present location as it did from Australia many moons ago, now that the heaviness of the ice field is slowly being lifted from it.

An interesting supposition, SEU...
I thought it was Pangea, but I guess that came afterwards...:-)
Ojorf
2.7 / 5 (7) Jun 22, 2018
Ow, this porridge is too hot.
Ew, this porridge is too cold.

Left foot in a bucket of boiling water.
Right foot in a bucket of ice.

Rising land pins underwater ice.
Rising land melts terrestrial ice faster.

The average American has 1.4 siblings.
The rest have one or three for the most part.

Using anecdotes for science is not very functional.
Sample sizes of 'one' do not make a statistic.


Ow, this poster is too stupid.
Ew, this poster is plain mad.

Left foot firmly in his mouth.
Right foot floating in the clouds.

66 years old already.
Science still eludes him.

The average denier has 1.4 brain cells.
The rest have one or three for the most part.

Using anecdotes for science is not very functional, no.
Idiotic posts do not make a point.

Surveillance_Egg_Unit
5 / 5 (3) Jun 22, 2018
Ow, this porridge is too hot.
Ew, this porridge is too cold.

Left foot in a bucket of boiling water.
Right foot in a bucket of ice.

Rising land pins underwater ice.
Rising land melts terrestrial ice faster.

The average American has 1.4 siblings.
The rest have one or three for the most part.

Using anecdotes for science is not very functional.
Sample sizes of 'one' do not make a statistic.


Ow, this poster is too stupid.
Ew, this poster is plain mad.

Left foot firmly in his mouth.
Right foot floating in the clouds.

66 years old already.
Science still eludes him.

The average denier has 1.4 brain cells.
The rest have one or three for the most part.

Using anecdotes for science is not very functional, no.
Idiotic posts do not make a point.



Haiku?
Surveillance_Egg_Unit
5 / 5 (3) Jun 22, 2018
Just curious about this, so I consulted Wikipedia for Gondwana.
...
I would find it very interesting if the whole of Antarctica might be beginning the process of drifting away from its present location as it did from Australia many moons ago, now that the heaviness of the ice field is slowly being lifted from it.

An interesting supposition, SEU...
I thought it was Pangea, but I guess that came afterwards...:-)

says W Gyre

I believe that Pangaea included Europe, North Amverica, Russia. While Gondwana included South America, Africa, Australia and Antarctica. The Rift Valley in East Africa is splitting and moving eastward currently. The valley will become an inland sea, possibly.
EnricM
5 / 5 (3) Jun 22, 2018
Good news thus? Does it mean we Dutch don't have to emigrate to Germany? Please...
It made me actually think about Green Mars.
chemhaznet1
not rated yet Jun 22, 2018
Good news thus? Does it mean we Dutch don't have to emigrate to Germany? Please...
It made me actually think about Green Mars.

Are you referring to Kim Stanley Robinson's Green Mars?
5 Star Rating for you, Eric.
philstacy9
1.6 / 5 (7) Jun 22, 2018
How Well Do Global Warming Predictions Stand Up?
https://www.wsj.c...29623442
It was just orchestrated political propaganda.
ZoeBell
Jun 22, 2018
This comment has been removed by a moderator.
Surveillance_Egg_Unit
3.4 / 5 (5) Jun 23, 2018
How Well Do Global Warming Predictions Stand Up?
https://www.wsj.c...29623442
It was just orchestrated political propaganda.

says pstacy

Political propaganda serves the purpose of motivating the rabble to become so outraged that they will mobilise their hordes to block street traffic and the normal ebb and flow of pedestrian traffic, where the pedestrians are often set upon and beaten for not being equally outraged enough to drop everything and join the rabble-rousers, in particular whenever there are TV cameras in the vicinity.
Global warming aka climate change propaganda also sometimes motivates street demonstrations that are short-lived since the rabble don't really give even one damn about the environmental situation, particularly if it involves the recycling of materials which they are usually too lazy to do.

Political propaganda is far more interesting.
Surveillance_Egg_Unit
3 / 5 (6) Jun 23, 2018
Good news thus? Does it mean we Dutch don't have to emigrate to Germany? Please...
It made me actually think about Green Mars.

says EnricM

It is possible that you Nederlanders will choose to build higher dikes - say about 25 feet high or more, with energy from windmills to power the pumps that will return flood waters to the sea.
If climate change is going to happen, remember that this has all happened many times before, and humans had nothing to do with it.

Zuiderzee Works in Wikipedia
Ojorf
2.3 / 5 (6) Jun 24, 2018
Just curious about this, so I consulted Wikipedia for Gondwana.
...
I would find it very interesting if the whole of Antarctica might be beginning the process of drifting away from its present location as it did from Australia many moons ago, now that the heaviness of the ice field is slowly being lifted from it.

An interesting supposition, SEU...
I thought it was Pangea, but I guess that came afterwards...:-)


Type in your address and pick a date, find out where you lived up to 750 mya.

http://dinosaurpi...-earth#0
Surveillance_Egg_Unit
5 / 5 (4) Jun 24, 2018
Very good website, Ojorf. Thanks for including it in the mix. It shows the ever-changing Earth and it has made me wonder at the future configurations of the continents in another 20 million or so Earth years. I hope to be around, if only in spirit.
Ojorf
2.6 / 5 (5) Jun 24, 2018
Thanks S_E_U, let's hope all goes well, technology keeps improving exponentially, hyper-intelligent AI's shepherd us safely through the singularity, this all in our lifetimes, so we can all watch the continents change configuration over the next 20 million years or so if we feel like it.
Surveillance_Egg_Unit
5 / 5 (3) Jun 24, 2018
Yes Ojorf, it certainly is a source of great pleasure, knowing that quite possibly within our lifetime, our ability to mechanise our future AI 'brothers and sisters' into, not only for the purpose of ensuring planet Earth's safety, but also to house our own Organic Machine brain matter within a metallic cranium. For this, our scientific knowledge of the human brain will need to vastly improve to chemically and electrically preserve our brain material to avoid deterioration of such brain material. Without such chemistry the brain will no longer function at the normal end of its life and humans, who are, indeed, Organic Machines, would die off in their time.

I have come to the conclusion that humans, animals, and even most plants and bacteria ARE organic machines, and are just as mechanised as AI. Not everyone would agree with that and I can understand their unwillingness to be referred to as "MACHINES". Bur indeed, all organic life forms of Earth and elsewhere ARE machines.
Thorium Boy
2.6 / 5 (5) Jun 25, 2018
Ice is accumulating in the Antarctic faster overall than is dissipating. But the global warmers studiously avoid mentioning the WHOLE continent.
Surveillance_Egg_Unit
4 / 5 (4) Jun 25, 2018
Ice is accumulating in the Antarctic faster overall than is dissipating. But the global warmers studiously avoid mentioning the WHOLE continent.


It's really hard to tell, but it is possible that at least SOME humans are living a dissatisfied existence UNLESS they are given a certain amount of stress and strain to grumble over...in this case, their belief that planet Earth will no longer be a place where they can retire comfortably and enjoy old age because it will get too hot. But notice that many of them are those who move to the southern climates where it can get to over 100 degrees F.(37.778 Celsius) once they are able to...away from the ice and snow of the North.

Antarctica and the penguins will survive as they have for millions of years. Just leave them be.
Da Schneib
1 / 5 (1) Jun 25, 2018
Isn't that amazing, when all the ice is melting off it.
SteveS
5 / 5 (4) Jun 25, 2018
Ice is accumulating in the Antarctic faster overall than is dissipating. But the global warmers studiously avoid mentioning the WHOLE continent.

https://phys.org/...sea.html
"Between 2012 and 2017 the continent lost 219 billion tonnes of ice per year"
Surveillance_Egg_Unit
3.7 / 5 (3) Jun 25, 2018
Ice is accumulating in the Antarctic faster overall than is dissipating. But the global warmers studiously avoid mentioning the WHOLE continent.

https://phys.org/...sea.html
"Between 2012 and 2017 the continent lost 219 billion tonnes of ice per year"


So, are you saying that the whole continent of Antarctica, from North - South, East - West has, and is, losing all of its ice fields to the ocean and will never gain it back? If so, are you absolutely, positively certain that the ice/snow will never accumulate again on that continent and the Earth will become as hot as the deserts?
Very interesting.
So, within a five year period, the Antarctic lost 1095 billion tonnes of ice. Is that so? Hmmmm
Sounds to me as though there are active volcanos under all the ice that is doing the melting.
Surveillance_Egg_Unit
4 / 5 (4) Jun 25, 2018
Oh wait. Of course! It's the Russians who are doing it. And it's still all Bush's fault. We can't forget to blame Dubya.
Da Schneib
1 / 5 (1) Jun 25, 2018
Looks like it's the Americans who are doing it.

On Earth.
SteveS
5 / 5 (3) Jun 25, 2018
Ice is accumulating in the Antarctic faster overall than is dissipating. But the global warmers studiously avoid mentioning the WHOLE continent.

https://phys.org/...sea.html
"Between 2012 and 2017 the continent lost 219 billion tonnes of ice per year"


So, are you saying that...


I'm not saying anything, I think the quote marks make it clear that I was quoting the linked article in response to Thorium Boy's comment. Why do you feel that you have to put words into peoples mouths to make your point?

With regard to you volcano theory, I'm afraid current data doesn't support it. There are volcanoes but there has been no significant antarctic wide change in geothermal heat flux that corresponds to the rate of ice loss.

https://agupubs.o...GL075609
leetennant
5 / 5 (2) Jun 25, 2018

Sounds to me as though there are active volcanos under all the ice that is doing the melting.


Interestingly, volcanoes did not exist before CO2 levels started rising.
antigoracle
1 / 5 (4) Jun 26, 2018

Sounds to me as though there are active volcanos under all the ice that is doing the melting.


Interestingly, volcanoes did not exist before CO2 levels started rising.


Non-interestingly, this braying Chicken Little Jackass is clueless to the fact that volcanoes can go dormant.
Digitalbookworm5678
not rated yet Jun 26, 2018
Just products of our 'Selfish Genes'?

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