Antarctic study shows central ice sheet is stable since milder times

May 5, 2017, University of Edinburgh
Researchers drilling a bedrock core in West Antarctica. Credit: David Sugden

Central parts of Antarctica's ice sheet have been stable for millions of years, from a time when conditions were considerably warmer than now, research suggests.

The study of mountains in West Antarctica will help scientists improve their predictions of how the region might respond to continuing climate change. Its findings could also show how ice loss might contribute to .

Although the discovery demonstrates the long-term stability of some parts of Antarctica's , scientists remain concerned that ice at its coastline is vulnerable to rising temperatures.

Researchers from the Universities of Edinburgh and Northumbria studied rocks on slopes of the Ellsworth Mountains, whose peaks protrude through the ice sheet.

By mapping and analysing surface rocks—including measuring their exposure to cosmic rays - researchers calculated that the mountains have been shaped by an ice sheet over a million-year period, beginning in a climate some 20C warmer than at present.

The last time such climates existed in the mountains of Antarctica was 14 million years ago when vegetation grew in the mountains and beetles thrived. Antarctica's climate at the time would be similar to that of modern day Patagonia or Greenland.

This time marked the start of a period of cooling and the growth of a large ice sheet that extended offshore around the Antarctic continent. Glaciers have subsequently cut deep into the landscape, leaving a high-tide mark - known as a trimline—in the exposed peaks of the Ellsworth range.

The extended ice sheet cooled the oceans and atmosphere, helping form the world of today, researchers say. Their study is among the first to find evidence for this period in West Antarctica.

The research, published in Earth and Planetary Science Letters, was done in collaboration with the Scottish Universities Environmental Research Centre. It was funded by the UK Natural Environment Research Council and supported by British Antarctic Survey.

Professor David Sugden, of the University of Edinburgh's School of GeoSciences, said: "These findings help us understand how the Antarctic Ice Sheet has evolved, and to fine-tune our models and predict its future. The preservation of old rock surfaces is testimony to the stability of at least the central parts of the Antarctic Ice Sheet—but we are still very concerned over other parts of Antarctica amid ."

Explore further: Antarctic study identifies melting ice sheet's role in sea level rise

Related Stories

West Antarctic ice sheet formed earlier than thought

October 9, 2013

About 34 million years ago, Earth transitioned from a warm "greenhouse" climate to a cold "icehouse" climate, marking the transition between the Eocene and Oligocene epochs. This transition has been associated with the formation ...

New Antarctic ice discovery aids future climate predictions

August 16, 2016

A team of British climate scientists comparing today's environment with the warm period before the last ice age has discovered a 65% reduction of Antarctic sea ice around 128,000 years ago. The finding is an important contribution ...

Recommended for you

Matter waves and quantum splinters

March 25, 2019

Physicists in the United States, Austria and Brazil have shown that shaking ultracold Bose-Einstein condensates (BECs) can cause them to either divide into uniform segments or shatter into unpredictable splinters, depending ...

How tree diversity regulates invading forest pests

March 25, 2019

A national-scale study of U.S. forests found strong relationships between the diversity of native tree species and the number of nonnative pests that pose economic and ecological threats to the nation's forests.

Study suggests trees are crucial to the future of our cities

March 25, 2019

The shade of a single tree can provide welcome relief from the hot summer sun. But when that single tree is part of a small forest, it creates a profound cooling effect. According to a study published today in the Proceedings ...

13 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Lino235
2.1 / 5 (11) May 05, 2017
The temperature was "much warmer" millions of years ago? Well, was it AGW? Did humans do it?

And, if not, then how in the world do we 'stop' the earth from warming if it, the earth, wants to 'warm up'? Any answers?
greenonions1
3.7 / 5 (10) May 05, 2017
Lino235 - how do we know that it was warmer millions of years ago? Could it be that scientists have studied the geological history of the earth - using proxy data - to ascertain within error bounds - what the earth temperature and climate were?
Well, was it AGW? Did humans do it?
No - it was a combination of many non human factors - such as Milankovich cycles, atmospheric content, solar radiation levels, plate tectonics, ocean currents, etc. Do you think that the same scientists who have spent so many million hours of research into establishing the body of knowledge regarding the climate, are not aware of all of these factors?
Those same scientists are sounding the alarm regarding the current human induced warming trend - and perhaps if we reduce our carbon emissions - we can at least slow the warming process down - and buy time to figure out a best path forward.
Anonym
2.1 / 5 (11) May 06, 2017
Quit the Malthusian Death Cult, Greenonions. We don't need to "buy time." Even if AGW proves out, the "dire" consequences won't be "catastrophic" for 100 years or more. It's absurd to believe that people won't figure out a workaround --- if one is needed ---- during the coming century. But why would it be? Warm is good because everyone eats.
greenonions1
4 / 5 (9) May 06, 2017
Quit the Malthusian Death Cult, Greenonions.
I see it as more of a realist - and from someone who cares. There are 7.5 billion of us now - and that could go as high as 11 billion. Given that a number of regions face famine today - seems to me we have some challenges to address. Yes - much or all of that may be addressed by better organization, and better technology. But we don't address it by putting our fingers in our ears. I don't hear many solutions coming from the anti science crowd. Just glib insults, and conspiracy theories.
Warm is good because everyone eats.
That is incredibly glib. Perhaps a warmer world will be better, perhaps not. You seem to be one of the people willing to roll the dice - and I advocate listening to the scientists.
Benni
2 / 5 (8) May 06, 2017
These kinds of narratives on this website need to cease immediately, they are simply creating distortions to the AGW Narratives.

The AGWs need their GW, Black Hole & Dark Matter fantasies, so by what right does science & the Laws of Physics have any authority to intrude on the rights of those who want to indulge in such fantasies?

Why can't science professionals just leave it be, they should bow to science fiction & allow the fantasyland pseudo-science of overage Trekkies be the norm.
greenonions1
4.4 / 5 (7) May 06, 2017
What a fascinating twist Benni is able to accomplish. I have no opinion on GW, Black Holes, Dark Matter, or even climate change. It would seem foolish to me to have an 'opinion' on these topics - just as it would be to have an 'opinion' on the age of the earth (just an example). So why would Benni say
The AGWs need their GW, Black Hole & Dark Matter fantasies
Are these three topics - not ones being proposed, and researched by the science community? Yet Benni twists it around - and accuses the science community - as being the ones indulging in 'fantasies.'

Quite interesting gymnastics.....
antigoracle
1.7 / 5 (6) May 06, 2017
It's too cold in central Antarctica, so the magical CO2 does not want to go there
Benni
1.6 / 5 (7) May 06, 2017
So why would Benni say
The AGWs need their GW, Black Hole & Dark Matter fantasies


.....because this bunch is such a clubby group of like minded funny farm science advocates living on this site. I could give you the list of names, but why bother, you already know who they are & so do they, right Schneibo?
Da Schneib
4.2 / 5 (5) May 06, 2017
@Lenni is innumerate and as such incompetent to judge.

-m'' + m'n' - m'² - 2m'/r = 0
m'' + m'² - m'n' - 2m'/r = 0
e⁻²ⁿ (1 + m'r - n'r) - 1 = 0
R₂₂ sin² ϕ = 0
Source: http://www.etsu.e...esis.pdf
And another reminder:
E² = (pc)² + (mc²)²
https://phys.org/...rgy.html
https://phys.org/...ole.html

I wouldn't believe a a single thing @Lenni says.
greenonions1
4.9 / 5 (7) May 06, 2017
because this bunch is such a clubby group of like minded funny farm science advocates living on this site.
Well - I was talking more generally about the science community. I guess there is going to tend to be a correlation - between understanding the consensus science on AGW, and understanding the consensus science on other topics such as evolution, or black holes etc. The point you totally miss - is that you really use a twist of logic - to accuse people who simply advocate for the traditional process of science - of indulging in "fantasies." Surely promoting an evidence based process - makes me the one grounded, and you the one on the funny farm side of the issues.
TrollBane
5 / 5 (1) May 06, 2017
"Lenni" Nice jab. Anybody else see the Steinbeck reference?
ChrisG65
5 / 5 (4) May 07, 2017
@Lino235, There is no magic. Neither the earth nor anything else "wants" to warm up. Things don't warm up unless they gain energy, and the cause of the earth gaining energy has been identified with gas spectroscopy, a sub-set of thermodynamics about 150 years old. Just because you don't understand the last 150 years of science does not mean that it is all wrong.
barakn
5 / 5 (2) May 08, 2017
Warm is good because everyone eats. -Anonym

Then why does a world hunger map show hunger centered on the equator? http://www2.johna...0062.jpg

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.