![icesheets[1]](http://wattsupwiththat.files.wordpress.com/2013/09/icesheets1.jpg?quality=83)
From the University of California – Santa Barbara
West Antarctica ice sheet existed 20 million years earlier than previously thought
(Santa Barbara, Calif.) –– The results of research conducted by professors at UC Santa Barbara and colleagues mark the beginning of a new paradigm for our understanding of the history of Earth’s great global ice sheets. The research shows that, contrary to the popularly held scientific view, an ice sheet on West Antarctica existed 20 million years earlier than previously thought.
The findings indicate that ice sheets first grew on the West Antarctic subcontinent at the start of a global transition from warm greenhouse conditions to a cool icehouse climate 34 million years ago. Previous computer simulations were unable to produce the amount of ice that geological records suggest existed at that time because neighboring East Antarctica alone could not support it. The findings were published today in Geophysical Research Letters, a journal of the American Geophysical Union.
Given that more ice grew than could be hosted only on East Antarctica, some researchers proposed that the missing ice formed in the northern hemisphere, many millions of years before the documented ice growth in that hemisphere, which started about 3 million years ago. But the new research shows it is not necessary to have ice hosted in the northern polar regions at the start of greenhouse-icehouse transition.
Earlier research published in 2009 and 2012 by the same team showed that West Antarctica bedrock was much higher in elevation at the time of the global climate transition than it is today, with much of its land above sea level. The belief that West Antarctic elevations had always been low lying (as they are today) led researchers to ignore it in past studies. The new research presents compelling evidence that this higher land mass enabled a large ice sheet to be hosted earlier than previously realized, despite a warmer ocean in the past.
“Our new model identifies West Antarctica as the site needed for the accumulation of the extra ice on Earth at that time,” said lead author Douglas S. Wilson, a research geophysicist in UCSB’s Department of Earth Science and Marine Science Institute. “We find that the West Antarctic Ice Sheet first appeared earlier than the previously accepted timing of its initiation sometime in the Miocene, about 14 million years ago. In fact, our model shows it appeared at the same time as the massive East Antarctic Ice Sheet some 20 million years earlier.”
Wilson and his team used a sophisticated numerical ice sheet model to support this view. Using their new bedrock elevation map for the Antarctic continent, the researchers created a computer simulation of the initiation of the Antarctic ice sheets. Unlike previous computer simulations of Antarctic glaciation, this research found the nascent Antarctic ice sheet included substantial ice on the subcontinent of West Antarctica. The modern West Antarctic Ice Sheet contains about 10 percent of the total ice on Antarctica and is similar in scale to the Greenland Ice Sheet.
West Antarctica and Greenland are both major players in scenarios of sea level rise due to global warming because of the sensitivity of the ice sheets on these subcontinents. Recent scientific estimates conclude that global sea level would rise an average of 11 feet should the West Antarctic Ice Sheet melt. This amount would add to sea level rise from the melting of the Greenland ice sheet (about 24 feet).
The UCSB researchers computed a range of ice sheets that consider the uncertainty in the topographic reconstructions, all of which show ice growth on East and West Antarctica 34 million years ago. A surprising result is that the total volume of ice on East and West Antarctica at that time could be more than 1.4 times greater than previously realized and was likely larger than the ice sheet on Antarctica today.
“We feel it is important for the public to know that the origins of the West Antarctic Ice Sheet are under increased scrutiny and that scientists are paying close attention to its role in Earth’s climate now and in the past,” concluded co-author Bruce Luyendyk, UCSB professor emeritus in the Department of Earth Science and research professor at the campus’s Earth Research Institute.
Other co-authors include David Pollard of the Earth and Environmental Systems Institute at Pennsylvania State University, Robert M. DeConto of the Department of Geosciences at the University of Massachusetts, Amherst, and Stewart S.R. Jamieson of the Department of Geography at Durham University in the United Kingdom.
The National Science Foundation’s Office of Polar Programs and the United Kingdom’s Natural Environment Research Council supported this research.
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Brian says:
September 4, 2013 at 3:50 pm
Maybe you’re joking, but it’s Eastern Hemisphere & Western Hemisphere, divided by the Greenwich or Prime Meridian.
Rats. When the article said they had done “research,” I hoped they had done some actual on-the-ground work — perhaps discovering geological clues, perhaps uncovering evidence of ancient flora or fauna — that provided the evidence for the new conclusion. Turns out it was just computer models?
Computer models can be useful and valuable in many instances, but it seems we need to come up with a separate word to distinguish actual observational science from modeling. Calling all the modeling efforts “research” seems a stretch in some cases.
It seems that 97% of earth scientists are sitting at their desks playing computer modelling. Maybe they should be banned from computers until they have done 30 years field work and got a little wear on their boots.
milodonharlani says:
September 4, 2013 at 3:45 pm
=====
Thanks!
….not paying much attention…I only remembered ‘ice’ “Antarctica” 34 mya
Ok , if the ice is so old ,how where trees growing there in the past. When Scott made his trip and found tree fossils they were not 20 million years old from what I have read. Sorry I can’t find my reference.
This was already known.
The ice-rafted debris and glacial erratics discovered by the ocean drilling programs going back to the 1980s had already determined that Antarctica glaciated over in less than 100,000 years between 33.6 Mya and 33.5 Mya. The extent of the glaciers at the time extended right to the continental shelves of all of Antarctica including West Antarctica.
By 27 Mya, the glaciers on West Antarctica melted back and, as a whole, about half of the glaciers on the continent melted. They didn’t grow back again until starting about 14 Mya and then complete glaciation occurred again just 3 Mya.
The timeline of geographic and temp changes going back 45 Mys.
http://s22.postimg.org/804qp4xo1/Temp_Geography_45_Mys.png
“””””……milodonharlani says:
September 4, 2013 at 1:05 pm
george e. smith says:
September 4, 2013 at 12:59 pm
The scary part is that it’s not only getting older & more tenuous all the time, but that the aging appears to be speeding up!…….”””””
Dang ! are you sure on that ? Whew ! that’s a relief; I thought it was just me slowing down .
george e. smith says:
September 4, 2013 at 9:18 pm
In the immortal words of Albert Einstein, “Alles ist relativ!”
Antarctic Beeches grow in a few places in SE Queensland. (And NE NSW?) There’s a closely related tree species in South America.
Getting a handle on the ages of the Antarctic ice sheets will give us a better estimate for the time of the breakup of the ancient Southern supercontinent into our present Southern continents.
Obviously, the breakup happened before Antarctica was thoroughly covered by continental glaciers. If the continental glaciers had come first, there wouldn’t be any surviving Antarctic Beeches for natural history buffs to enjoy. 🙂
A side benefit will be better estimates for the rate of genetic drift in these tree species.
And that piri reis map?
Don’t know about anybody else, but I lost the will to live when they said they used a “sophisticated ice model”! Oh, when will they ever learn to use the proper correct language if they want people to believe their little X-Box360 Lara Croft fantasy worlds?
Now, let’s redefine Consensus, yet again: A long time ago, say 2,500 years ago, with the exception of a few Greeks, the general consensus as that the Earth was flat, & that were one sail to far this way or tat, they would full off the edge to oblivion! This strongly held view lasted pretty much until the mid-seventeenth century, rigidly & brutally enforced by the UNIPCC of its day, the Holy Roman Catholic Church! Then some fella called Copernicus decided that all was not well, followed by Gallileo. Eventually, thanks to an age of enlightenment, the consensus changed! Gravity would ten be discovered as a result! e now know differently!
Throughout history, & in particular, the dark t middle ages until the early eighteenth century, I was a general consensus that witches were real, &were the rot cause of all evil! The punishments for these poor wretched women, based upon the soundest of scientific thinking of the day, was to place them on a ducking stool & repeatedly duck them under water in a pond or stream until the confessed their crimes against Humanity & God. If the poor girl drowned, then she was declared innocent, if the poor girl had the temerity to hold her breath & survive, she would be declared guilty, the burned to death at the stake! We now know differently!
For many hundreds of years Malaria (or the old English word Ague, mentioned Shakepeare’s plays set in temperate climes, numerous times), was believed to be an airborne disease, hence the name malaria, Italian for “bad air”! It wasn’t for centuries that it was discovered to be transmitted by mosquitos We now know differently!
The general scientific consensus in the mid to late 19th century, was that the cure for many an ill was to undergo a course of bloodletting! This would take the form of attaching slimey creatures to various bits of ones anatomy to suck out the bad blood, to the severing of main arteries, with the most unpleasant of results! We now know differently!
At the end of the nineteenth century, there were various Heath-Roberson attempts to achieve manned powered flight wit varying degrees of success & failure. This culminated in 1895 w the then President of the Royal Society to proclaim that “heavier than air flying machines were impossible!”. We now know differently!
In the mid 1970s the general scientific medical consensus was that peptic & gastric ulcers were caused by stress & some even said of eating too much spicy food. Two Antipodian medical scientists disagreed, & had the temerity to claim that they may even be caused by a bacterium, no less! Oh how they were pilloried & chastised for their stupidity & ignorance by the cream of the profession!! These two people eventually won the Nobel Prize for persistence in research & their eventual finding that that was indeed how such ulcers! We now know differently!!!!!
Before any scientist claims settled science, or even consensus, hey should think long & hard before doing so! A t B.
apologies for the typos!
Alan the Brit says:
September 5, 2013 at 8:08 am
Now, let’s redefine Consensus, yet again: A long time ago, say 2,500 years ago, with the exception of a few Greeks, the general consensus as that the Earth was flat, & that were one sail to far this way or tat, they would full off the edge to oblivion! This strongly held view lasted pretty much until the mid-seventeenth century, rigidly & brutally enforced by the UNIPCC of its day, the Holy Roman Catholic Church! Then some fella called Copernicus decided that all was not well, followed by Gallileo. Eventually, thanks to an age of enlightenment, the consensus changed! Gravity would ten be discovered as a result! e now know differently!
—————————–
Your general point about consensus is of course correct, but Earth was known to be spherical long before the mid-17th century or Copernicus’ 16th century. From at least the AD 400s, the Church not only recognized Earth to be a globe but added spheres upon spheres, advocating as it did the Ptolemaic system.
Some Early Church Fathers insisted upon a literal interpretation of the Bible, hence advocated a flat Earth, but this view was soon replaced in the Christian West by Greek science, geocentric & immobile but spherical.
Copernicus’ contribution was to argue that Earth goes around the Sun, not the Sun around the Earth. He did however wrongly keep Aristotle’s perfectly circular orbits.
Modellng…….
Interesting but still hocus pocus..
Stick a drill hole through the ice and hope to intersect underlying soils with contemporary pollen
A suitable target might be able to be defined with geophysics.
Find pollen then we’ll know,the age, not guess
milodonharlani says:
September 4, 2013 at 1:23 pm
A cursory search shows estimates of the universe are getting older. If you had done your research you would have found these links. When I said the estimates are for the universe getting older I was referring to recent works. That is the context. I’m not talking about ancient history. Before you call someone wrong maybe you should read more than just Wikipedia.
2004: The Universe, Seen Under The Gran Sasso Mountain, Seems To Be Older Than Expected
As a consequence, in the light of Luna’s new data, the age of our Universe passes from the previous estimate of about 13 billions years to that of about 14 billions years” explains Eugenio Coccia, director of Gran Sasso National Laboratories.
http://www.sciencedaily.com/releases/2004/05/040514030155.htm
2006: Universe Might be Bigger and Older than Expected
Scientists now estimate the universe to be about 13.7 billion years old (a figure that has seemed firm since 2003, based on measurements of radiation leftover from the Big Bang) and about 156 billion light-years wide.
The new finding implies that the universe is instead about 15.8 billion years old and about 180 billion light-years wide.
http://www.space.com/2707-universe-bigger-older-expected.html
leftturnandre says:
September 4, 2013 at 12:18 pm
Nice story, but what happened to the scientific method? Remember Richard Feynman, you start off with a guess. This is a guess, model or not. Then you check your guess against reality and find Scherer et al 1998:
http://www.sciencemag.org/content/281/5373/82
Unfortunately Scherer et al. are real scientists, i e they are willing to change their hypothesis when new data becomes available:
http://adsabs.harvard.edu/abs/2009EGUGA..11.5895S
So, sorry, but there is no concrete evidence for a late pleistocene WAIS collapse, but a growing amount of evidence that the WAIS has been fairly stable since MIS 31.
WUWT is one of my favourite sites. However, some of the comments are amongst my least favourite. Could we have a more forgiving attitude towards debate and uncertainty in scientific liteature, instead of a “point-scoring” antagonistic approach. The age of the Antarctic Ice Sheet has been debated for a long time, regarding whether it started at the Eocene Oligocene border around 34 Ma (timescale of Gradstein et al 2004) or sometime in the Miocene or at the Miocene Pliocene boundary (5 Ma ago) or later. The early evidence related to oxygen isotope variations, and the changes observed at the Eocene Oligocene boundary and later. Various researchers interpreted that information against geological and paleo-environmental information. However, it is not a done deal as to which theory or interpretation is correct. At present, the comments seem to be predominantly anti anything that comes out of a university research program. For example when Anthony highlighted research that showed the circum polar current may have been blocked by the volcanic ridge of the Scotia Arc, there seemed to be a barrage of anti-research-paper commentary. Meanwhile debate over which features may have blocked or allowed passage of the circum Antarctic current is quite a key issue regarding paleoclimate. Could I appeal that commentary be more balanced
Btw, this commentary in favour of a more open attitude to debate in the scientific literature comes from someone with >25 years in the oil industry, but who enjoys seeing academic debate.
leftturnandre says:
September 4, 2013 at 1:04 pm
Now we know that the oxygen isotopes in the benthic shells started the great enrichment only some 3.5 million years ago: http://www.lorraine-lisiecki.com/stack.html
I’m not sure if we can balance the ice volume /LR04 benthic stack but I would expect that there would be some tension between a huge early WAIS and the bentic isotopes/ice volume theory/hypothesis.
Sorry, but You are utterly wrong again. The first big drop comes withe the Oi-1 glaciation about 35 million years ago. There were oxygen isotopes before the LR04 stack starts you know, though the detail and dating is less precise. Check here for example:
http://www.sciencedirect.com/science/article/pii/S0031018298000935
Golden says:
September 5, 2013 at 9:53 am
You did not specify which time frame you meant for “always getting older”. Had you stated “between 2004 & 2006”, I’d have shown you all the studies since then which are back to being less than the outlier high estimate from 2006.
The current best measurement of the age of the universe is 13.798±0.037 billion years (13.798±0.037×10^9 years or 4.354±0.012×10^17 seconds), within the Lambda-CDM concordance model.
Planck Collaboration (2013). “Planck 2013 results. I. Overview of products and scientific results”. arXiv:1303.5062 [astro-ph.CO]
Bennett, C.L.; et al. (2013). “Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results”. arXiv:1212.5225 [astro-ph.CO]
Clearly, you are the commenter who needs to study the topics upon which you post. And, as before, you are wrong as wrong can be, upon whatever time scale you chose since 1929.
Keith says:
“The age of the Antarctic Ice Sheet has been debated for a long time, regarding whether it started at the Eocene Oligocene border around 34 Ma (timescale of Gradstein et al 2004) or sometime in the Miocene or at the Miocene Pliocene boundary (5 Ma ago) or later.”
I would say that the evidence that the first continent-wide glaciation in Antarctica was Oi-1 about 35 million years ago is overwhelming. The appearance of IRD (Ice Rafted Debris) in the surrounding seas is pretty uncontrovertible evidence that the ice extended to the coast on a large scale. And the simultaneous sharp 18O-shift is difficult to explain without a major ice-sheet.
The 5-or-14 million year debate is about when the ice-sheet was less-than continent wide for the last time and therefore also when the last tundra areas with vascular plants and land animals were eliminated. Personally I think that the strong evidence that the Dry Valleys in the Transantarctic Mountains have not had temperatures over freezing for any lengthy period for 14 million years strongly suggests the longer time scale. However if the valleys were at a considerably higher altitude during the Pliocene than they are now, middle-arctic conditions could possibly have existed near sea level. This would require some rather remarkable post-Pliocene tectonics in the Transantarctic Mountains, but it is possible.
The somewhat rabid attacks on academic research on WUWT are unfortunate, but probably inevitable. Many here are probably only familiar with “climate science” which is unfortunately replete with dubious methods, dodgy data, “spin” and outright fraud. Most research in most “hard science” fields is still good, though I am sorry to say that fraud and shoddy work seems to be on the increase almost everywhere.
GregK says:
Stick a drill hole through the ice and hope to intersect underlying soils with contemporary pollen
A suitable target might be able to be defined with geophysics.
Find pollen then we’ll know,the age, not guess
Its not nearly that simple.
We might not find any pollen (most ice-cores don’t)..
If we do, they might be redeposited (under an ice-sheet they almost certainly are, most Antarctic pollen is redeposited stuff from the Cretaceous or Paleogene)
Even if we do find pollen from the last plants to grow before the ice came, how do we date them? Pollen by themselves aren’t datable. We date them by indirect means, e. g. by knowing when those particular plants lived, or by dating the rocks we find them in. We have pollen from the last plants that lived in Antarctica, from the Meyer Desert Formation, and it has been disputed for 20 years whether they are 3 or 15 million years old.
“”””””……milodonharlani says:
September 5, 2013 at 11:36 am
Golden says:
September 5, 2013 at 9:53 am
You did not specify which time frame you meant for “always getting older”. Had you stated “between 2004 & 2006″, I’d have shown you all the studies since then which are back to being less than the outlier high estimate from 2006.
The current best measurement of the age of the universe is 13.798±0.037 billion years (13.798±0.037×10^9 years or 4.354±0.012×10^17 seconds), within the Lambda-CDM concordance model…….””””””
The Hewlett Packard (now Agilent Technologies) R&D department (Standards lab) used to have (probably still does) two Cesium Beam atomic clocks, (which HP made), set to the National Bureau of Standards (now NIST) time standard, and the second one to the US Naval Observatory Time Standard.
They kept the two standards, because their atomic clock (which you can buy) is about the only commercial instrument, that could tell the difference.
As I recall, the NBS clock claimed that the universe was one day older than the US Naval Observatory claims.
When finally those two parties came together to figure out what the time really was, it was NBS who set their clock to the correct USNO time. That 2 parts in 10^13.
“West Antarctica ice sheet might have existed 20 million years earlier than previously thought, we really don’t know.”
There, title fixed.
Then how did people map the land underneath a few thousand years ago?