From the UNIVERSITY OF EXETER
A new study reveals the sub-antarctic island of South Georgia — famous for its wildlife — was covered by a massive ice cap during the last ice age.
The results are published today in the journal Nature Communications. South Georgia, the remote UK territory where Sir Ernest Shackleton landed during his dramatic voyage from Antarctica to rescue the team of his Endurance expedition, is home to various species of penguins and seals, and has featured on documentaries including Frozen Planet and Planet Earth II.
The island’s unusual plant communities and marine biodiversity, which are protected within a large Marine Protected Area, have survived and evolved through multiple glacial cycles for tens or even hundreds of thousands of years.
But a research team led by the University of Exeter has discovered that at the peak of the ice age, about 20,000 years ago, ice thickened and extended tens of kilometres from the island — far further than previously believed.
This would have driven its biological communities to small mountain and seabed refuges to survive.
The researchers also found the ice has been sensitive to short-lived cooling and warming — growing and shrinking dramatically as the climate changed.
“Although the island is small framed against Antarctica’s great ice sheets, the discovery of an extensive past ice cap on South Georgia is an important result,” said lead author Dr Alastair Graham, of the University of Exeter.
“The survival of ocean ecosystems is linked heavily to patterns of glaciation, so it is very interesting to know where and how sea-bed creatures lived through the ice age, and how the cycles of ice-cap change have influenced the biodiversity.
“Life must have really only survived at the edges, at and beyond the ice margins.
“Our work also provides a key data point for ice sheet and climate models, which will now need to simulate a large ice field on South Georgia during the last ice age if they are to have confidence in their outputs.”
The team from the UK, Germany and Australia travelled to the island on British Antarctic Survey’s RRS James Clark Ross in 2012, and the German RV Polarstern in 2013 to carry out sonar mapping using sophisticated sonar technology mounted to the hulls of ice-breaking vessels.
They also used weighted gravity corers to retrieve samples of ancient sediment from the ice-carved troughs that radiate from the island to reveal past patterns of glacier expansion and melting.
The researchers discovered hundreds of distinct ridges bulldozed into the seabed by glaciers, showing that — contrary to previous estimates — the ice extended across South Georgia’s vast continental shelf.
Co-author Duanne White, from the University of Canberra, said: “Glaciers in the sub-Antarctic are retreating dramatically today, in response to an ever-warming atmosphere and ocean.
“It is perhaps unsurprising that South Georgia’s glaciers were sensitive to climate change in the past, but our work has really shown that they were dynamic and underwent big changes over geological time.
“Improving the history of glacier behaviour on South Georgia even further is now essential so that we have a long-term context for the alarming recession we are witnessing right now.”
Co-author Dominic Hodgson, from British Antarctic Survey, said: “The sub-antarctic is a region experiencing massive climate changes with rapidly shrinking glaciers and the loss of several ice caps in recent decades.
“Studying the longer-term history of glacial changes in the region is key to understanding the sensitivity of glaciers to climate change, and their impacts on biodiversity and species survival.”
The paper is entitled: “Major advance of South Georgia glaciers during the Antarctic Cold Reversal following extensive sub-Antarctic glaciation.”
###
A major advance in a settled science reveals a major omission in highly refined models that need more funding to incorporate new discoveries. What a racket.
Talk about a feed back loop!
That only stops if the research concludes that it has absolutely nothing to do with CO2 and global warming.
dam 1953
Why should the research conclude that ‘it’ “has absolutely nothing to do with CO2 and global warming.”
That way madness lies – and no funding, no attribution and no tenure also lie.
It’s all LIE, I guess . . . .
Auto.
Sadly, more like feed the fruit loops.
Orbital factors and CO2 are not exclusive. Study some climate science.
CO2 isn’t the only factor that influences climate.
You know that, right?
@crackers345
I see your /sarc detector is broken…
What? We know everything about Earth’s history? why shouldn’t we research this?
WE don’t want to spend the resources on this research.
YOU and the mouse in your pocket are welcome to do whatever you want to do.
We think we know more than we do
We think that the Earth should and shall be unchanging so we build our permanent communities on the coast and wail about sea level rise (never mind the lessons of the past and archaeological sites that are now but weren’t then under water due to past sea level rise)
We think that iced poles is the ideal climate and wail when this status quo changes.
We think that a warming greening world is bad and wail when these changes occur.
We think that Polar Ice should always be what it was in the 1970’s (neither shrinking nor growing)
We think that Sea Level should always be what it was in the 1970’s (neither increasing nor subsiding)
We think that the temperatures should be what they were back in 1850 (pre industrial)
Worst of all we, in our hubris, think that we can control these constantly changing environments in our ever dynamic world such that it never changes.
High latitude islands had more ice sheet at the peak of the last glaciation than now. What a discovery–NOT!
Griff, I think it is impossible to slay the settled science straw man. I am in two minds as to whether it is worth continually pointing it out or not. It is obvious to anyone who bothered to look that nobody claimed that glaciation on S Georgia was settled science, nor that everybody has always agreed that models need further refining, but the story is just too good to let go.
Maybe we should interpret the study as a warning of how fast life will be endangered there when the next drop in temperature occurs, which history shows as inevitable.
“Griff, I think it is impossible to slay the settled science straw man. I am in two minds as to whether it is worth continually pointing it out or not. ”
the straw man is that no climate scientist has ever claimed that all the science is settled.
What is settled?
1. C02 is a GHG
2. Human emissions increase C02
3. Uncreasing C02 will warm NOT cool the planet.
What is unsettled?
1. How much warming?
2. What other changes can we expect
3. How and where will these develop.
4. what was the past like… EXACTLY.
“The” science is an imprecise term that only skeptics misuse and abuse
Nevertheless it is always fun to read the knee jerk responses here anytime any new science discovery is made. I am in the middle of constructing a “skeptic bot” that will automatically parrot skeptic talking points.
Its a mindlesss creature
Griff
I am in agreement, earth science is at a very early stage of full understanding. The more hard data that is available the better. There are still more assumptions than fact.
AWK
The science is settled
AWK
97% of scientists agree
AWK
Temperature will rise by 8.5 degrees
AWK
Sea level rise is increasing
AWK
The Arctic will be ice free in
20022007200920122015a few more yearsAWK
Steve M, What has unsettled the science?
““The” science is an imprecise term that only skeptics misuse and abuse’
And he was doing so well up to that point.
“Steve M, What has unsettled the science?”
Nothing. We know now, what has been known since 1896.
C02 is a GHG
GHGs warm the planet
In 1896, we estimated that doubling c02 would cause a 5-6C rise in temperatures..
Today the estimate is 1.5-4.5C
No amount of blog comments will change the physics: C02 is a GHG
No blog comment, no half baked blog post, will change the fact that GHGs warm the planet they do no cool the planet.
And nothing I have seen from skeptics has narrowed the range of uncertainty in ECS..
“3. [I]ncreasing C02 will warm NOT cool the planet.”
This is not settled. It will warm not cool the surface thermometers. The surface boundary layer is not the planet.
In what way do you think climate models model the deep past?
Incorrectly!
Can you cite three papers that model the deep past?
Dr. Sherlock Holmes is a busy man.
I thought Antarctica had been adding ice, billions of tons every year, for the last 20+ years. I understood ice flowed outwards from its points of accumulation. How do you add gigatons of ice and have shrinking glaciers at the same time? Or when White says says “Glaciers in the sub-Antarctic are retreating dramatically today, in response to an ever-warming atmosphere and ocean,” is he referring to the tip of the Antarctic Peninsula? Or the whole peninsula, which represents about 3% (rough guess) of the total land mass.
It’s a meme.
South Georgia is at least 10 degrees north of the Antarctic Peninsula. Antactica is surrounded by a vast and lonely ocean, and is sucking water out of the ocean at the rate of .22mm per year through mass gain. Where is this place on the map called “sub-Antactica”??
Hmm… Down under?
South Georgia’s latitude just makes it naturally more of a “cryospheric canary” (in my unwashed perspective).
Today, on March 17th, 2017, glaciers retreated dramatically.
Two points:
1) what is this “alarming recession” and similar nonsense these people want to ram down our throats? Where is the data?
2) I’m sorry but, look at the map. Why wouldn’t this area have been glaciated when all other areas at these latitudes were during glacial periods? Why the surprise?
Another superstar report from Surrey-by-the-sea (Exeter) University,
One point
I’m sorry but, look at the map….Exeter is in Devon !!(:-))
1saveenergy, of course Exeter is in Devon. It has become known as Surrey-by-the-Sea University because of the sheer numbers of students that go there from Surrey – and indeed surrounding county – schools. It’s a jolly place where such bright young things can be sure they will be among their chums, as indeed can the parents when they visit.
Those who drop out of school there are collectively referred to as “The Exiters of Exeter”, incidentally.
And a lot of former Londoners/Surreyites/Middlesexians (even Essex Boys and girls) sell their mean little two-up, two-downs in areas with good trains to London [No – not on Southern Railways routes. Never. Wash your mouth out!] and buy three bed detached houses, with gardens, in Exeter, Sidmouth, Paignton, even Tavistock [the Pannier Market, and Elliru Designs [I have bought from them], there are a wonder].
Auto
The University is situated near to the Jurassic coast, so they ought to have a good geology department and be familiar with past climates.
Bullwinkle: “Hey Rocky! Watch me pull a climate model out of this hat.”
Rocky: “That [nature] trick never works.”
Bullwinkle: “This time for sure!”
ROAR! (It’s worse than we thought)
Rocky: “And now folks, here’s some science we hope you’ll really like.”
That was a most adult-oriented cartoon in its day. Fractured Fairy-Tales was cool too.
Peabody and Sherman.
I wish there was a simpler phrase than “glaciation”. “[D]uring the last ice age” would have been — what, 250 mya? They mean, of course, “during the last [maximum extent of the ice of the current] ice age.”
The confusion helps people forget that we are now in an abnormally-cold era, aka “ice age”, even if the ice has retreated a bit just at present.
That is a big problem with the whole “global warming” thing, we are well below the average temperature of the Earth’s history when so many of these creatures we hear so much whinging about originally evolved. What would happen if the Ice Age actually ended and temperatures returned to non-Ice Age standards? These people would bleat that we were to blame. They remind of the ancient priests who started killing off the troublemakers as sacrifice to the gods when droughts or famines plagued the land. If we just kill off the economy Gaia will return the ice!
“I wish there was a simpler phrase than “glaciation”.”
“Stadials and interstadials are phases dividing the Quaternary period, the last 2.6 million years.”
https://en.wikipedia.org/wiki/Stadial
Some use the term “stade” — as in, The Vashon Glaciation or Vashon Stade
https://en.wikipedia.org/wiki/Vashon_Glaciation
From there you get to: Marine isotope stages (MIS) and great detail
https://en.wikipedia.org/wiki/Marine_isotope_stage
“Our work also provides a key data point for ice sheet and climate models, which will now need to simulate a large ice field on South Georgia during the last ice age if they are to have confidence in their outputs.”
Gee And I thought the science was settled.
Soooo.. they take +Anomaly A for Region X, combine it with -Anomaly B in region Y…etc, Integrate all the Anomalies around the globe at the same specific time T and come up with the delta for the proclamation .
The delta what? Temperature? What does that even tell anyone (if they could actually do it at time T in 3D) for the land sea and air in region X? If mean temperature is supposed to be the chosen proxy to represent the gain or loss of heat Q, how do you incorporate the ‘real mean’ parameters for specific heat, the dynamic incorporated latent heat processes, the phase change process occurring at that time in Regions X,Y…etc to properly relate Apple A to Apple B in relative enthalpy terms in order to proclaim the net up or down for the planet heating or cooling at that instant?
I feel so dumb compared to the settled Climate Scientists. But I’m old, so that’s OK with me. 🙂
OK. I am old also.
We learned something different in school!
If only it were that simple, but methinks they are trying to compare and contrast Apple A to Orange B to Banana C to…
Ah yes. Back in the day when weather was ever so pleasant for humans as they worked and played in shangri la. Bad ol CO2. Harming innocent glaciers.
The obligatory statement key for funding…
Perhaps?
Agreed. She’s stating the obvious.
Proving the obvious. Why waste the funds?
Well, it sounded, initially, like something worth investigating, and may be still, but the conclusions they draw… Maybe it’s just the way the presented them: The Earth did NOT have a static climate prior to us bad ol’ humans discovering that oil burns! Suh-prize, suh-prize, suh-prize!!!
.”….alarming recession we are witnessing right now.|
where?
In the Antarctic?
Blame any alarming rece$$ion$ on policies that fight climate change instead of adapting to it and fund the fantasy of sustainability through wind and solar.
Some crazy things have come from this `university`.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
I don’t see any alarming decrease in ice in the Antarctic.
there is some ice loss in the arctic
I am sure that is due to the movement of earth’s inner core more north east
hence we had problems in Japan, Iceland and now Italy. (over boiling…)
I predict LA could be next because it lies in that specific fault line that will get stress.
Neither do I, up to the point in 2016 when the satellite they used failed. Have a look at their Arctic data, they’re even better:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
tty
what is your point
the outlier peaks cannot possibly correct
Last I saw, Antarctica was losing ice, -180 +/- 10 Gt/yr for the period 2003-2013.
Veligcogna et al, GRL 2014
http://onlinelibrary.wiley.com/doi/10.1002/2014GL061052/abstract
The inner core isn’t moving. The only way it could move is if the earth were to be destroyed.
MarkW
how would you know it is not moving?
My datasets show that the NH is warming whilst the SH is not.
How do I explain this [if only to myself – because most of the others WANT to believe in global warming…]
Go down here in a gold mine [in South Africa] and discover the elephant in the room///
The North Magnetic Pole moves over time due to magnetic changes in the Earth’s core.[1] In 2001, it was determined by the Geological Survey of Canada to lie near Ellesmere Island in northern Canada at 81.3°N 110.8°W. It was situated at 83.1°N 117.8°W in 2005. In 2009, while still situated within the Canadian Arctic territorial claim at 84.9°N 131.0°W,[2] it was moving toward Russia at between 55 and 60 kilometres (34 and 37 mi) per year.[3] As of 2016, the pole is projected to have moved beyond the Canadian Arctic territorial claim to 86.4°N 166.3°W.[2]
I am not stressed, but earth maybe stressed at a few points where there seemed to have been dead volcanos for a long time…..
Henry P of course Etna is in the news because a few BBC “Journalists” were silly enough to close to an erupting volcano. But nobody is paying attention to Bogoslof in the Alaska islands that has been erupting since Dec 22. I think your analysis might prove correct re stress on tectonics.
asybot
thx.
I didn’t know about Bogoslof in the Alaska islands that has been erupting since Dec 22….
but it falls in line with my theory – i.e. a small movement of the inner core of earth. It is the only way to explain the accelerating pace of shift in the magnetic poles over the past 50 years.
We already had the major quakes in Japan.
The other major fault line runs through LA…..
I am glad I don’t live there right now.
If the inner core were moving (what is forcing it to move?), it would quickly show up in seismic observations, like those used to deduce the existence of the inner core and outer core.
Ummm… can we say for sure one way or the other?
“Inner Core – The solid innermost sphere of the Earth, about 1271 kilometers in radius. Examination of meteorites has led geologists to infer that the inner core is composed of iron and nickel.
Outer Core – A layer surrounding the inner core that is about 2270 kilometers thick and which is a liquid.
Mantle – A solid,…” (obtained with just one random internet search, NOT using Google)
…and so on, so the innermost core of the Earth is not firmly anchored to the layers above, and could indeed “move” relative to them, with ease. Now is that what causes the migrating poles? I have never seen a good explanation of why the poles move. I guess we must just accept that they do, at least there is good solid empirical evidence to support that claim.
There is no doubt about the NH and SH sea ice trends. What is still yet to be fully clarified is the real cause of the annual variations. When this has been qualified it will remove another AGW lever.
That way the skeptic community doesn’t have to rely on a change of president to act as chief scientist.
OK now I am having a problem with nomenclature. As I understand it, Earth is presently in an ice age, but between periods of glaciation. So, does the article really mean that the island was covered with ice during the last glacial period, and not the last ice age? Or am I misunderstanding the idea of what an ice age really is?
They are talking about 20kya, so they mean during the last glaciation. You would think that scientists would at least use the correct terminology.
Exactamundo…is it any wonder that the public has no clue we are in an ice age when scientist talk like it is over?
Robert, see RWT upthread
https://wattsupwiththat.com/2017/03/17/study-extensive-ice-cap-once-covered-sub-antarctic-island-of-south-georgia/comment-page-1/#comment-2453460
Scientists would.
Jpatrick March 17, 2017 at 10:38 am wrote:
“Or am I misunderstanding the idea of what an ice age really is?”
Yes, you are.
An ice age is glacial maximum. Last was 22 k yrs ago.
It does not sound surprising to me that S. Georgia had an extensive icecap in the last ice age. However, as I am not an expert in this field I am not aware of the current thinking about this detail.
You might be interested in how much sea ice it created, there’s always the challenge to learn.
Agreed. The location adjacent to Antarctica may have allowed a sea ice bridge to form more readily between the two. Personally, the more real data the better.
Who says any of the biological communities survived? What’s wrong with the theory that the island was repopulated during this inter-glacial?
There are no native mammals. link There are birds, who obviously can fly in. There are plants whose seeds can be carried on the wind or on birds. The same applies for insects.
So we have a really interesting ecosystem on South Georgia – “famous for its wildlife” – now that could not have existed in its present form when it was completely covered in an ice cap 20KYA.
Boy, all that global warming … it’s so terrible to contemplate!
The wildlife is indeed spectacular but almost exclusively marine (whales, seals, seabirds). And the landscape is spectacular too, largely due to glacial sculpturing.
There is only a single endemic land animal – a pipit. And the flora is depauperate with no endemic vascular plants, though there are some endemic mosses and half a dozen endemic insects and spiders. A single nunatak is probably enough to explain the survival of those.
This study gives a good example of what a remote island at high latitude in a circumpolar current near a polar land mass experiences while there is hemispheric glacial growth. It appears that life is slow to recover after “the big freeze”. Has anyone looked for skeletal remains of land animals here? Were there enigmatic species?
Really tty, your comments are almost always highly informative, but you know, insects, spiders etc. are animals. Last time I checked anyway.
You are right. I was careless, I should have said “land vertebrates”.
And as far as I know nobody has looked very hard for fossils there. South Georgia has only been emergent since the Late Miocene (at the most), so climate has always been cold there. I suppose that some vertebrates could have come across from Patagonia by sweepstake dispersal during the Pliocene. But land that has been glaciated has usually lost most of the sediments where fossils might be found, so we may never know. There is a good review of the geology here:
http://geology.geoscienceworld.org/content/42/4/299
But itt will probably be very hard going for a non-geologist.
That South Georgia has been completely glaciated in the fairly recent past is of course quite obvious to anyone who has been there and has some knowledge of glacial geomorphology.
As usual in cases like this the actual paper is a lot more sensible than the inane press release with its obligatory genuflection to CAGW.
Essentially they have mapped the shelf around South Georgia and found indubitable end moraines out to the shelf edge, showing that the whole shelf has been ice covered at least once. The relatively fresh and coherent glacial topography may indicate that the moraines are from a single glacial cycle, and that the maximum near the shelf edge was at LGM about 20,000 years ago, but there is no actual data that proves this. It could be much earlier (or later for that matter).
Dating of shells from an intermediate (but still offshore) moraine ridge (M2) suggests that it is due to an ice advance during to the Antarctic Cold Reversal (ACR) 12,800-14,500 BP. A core in an offshore trough suggests that the Island was quite heavily glaciated up to c. 10,000 years ago. What happened in the Holocene is uncertain since there is an obvious disconformity in the core. South Georgia is rather heavily glaciated today, by the way.
A few more cores, particularly near the shelf edge would have been most desirable. As it is now their interpretations are not strongly supported.
http://www.nature.com/articles/ncomms14798?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+ncomms%2Frss%2Fcurrent+(Nature+Communications+-+current)
I don’t think this kind of research is a waste. I used to watch and read about studies like these, pre-global warming days. The research was more curiousity about the past and was interesting. When it became the “we’re all destroying the planet with warming” it was no longer that interesting. Remove the politics and let the universities do the studies like they did in the past. Let them present the data with no commentary on global warming, but rather as interesting peek into the past. It worked before.
Actually, and somewhat surprisingly CAGW isn’t mentioned at all in the paper. The closest they get to it is:
“It follows that an improved understanding of South Georgia’s glaciations can shed light on ice mass response to climate variability in an under-sampled but regionally-important Southern Ocean sector, and can provide as yet unknown long-timescale context for changes in the sub-Antarctic cryosphere over recent decades.”
I have noticed a trend recently. CAGW is featured in the press release, but barely or not at all mentioned in the actual paper. It is almost as if some scientists are beginning to worry about deniability…
The MSM journalists will be quick to add alarmist spin to actual the scientific conclusions until the media owners quit rewarding it, or they are called out legally for it.
Mr. Watts, I am really surprised that you know so little about Quaternary science, and the current ice age we have been in for the last 2.5 million years. When you write about climate and weather conditions, do you not attempt to be as accurate as possible? Words really mean things, do they not?
So when you start out by talking about “the last ice age” you are automatically being disingenuous. We never, ever, left the last one. We’re still in it. The Pleistocene has been around ever since the quaternary began. If you are referring to the last ice sheets to cover the earth, then you are really talking about the last “Glaciation”. We’re just in an “interglacial at this time, and at the very end of it as well. We are soon due to descent into the next glaciation.
So please, be accurate about things science, because it affects your overall reputation. And like the saying “Its the Sun Stupid”, its also “The Glaciation Stupid”. Come on, get with it.
Actually “the last ice age” is frequently used for the MIS2-5d glacial cycle whose culmination is known as the LGM “Last Glacial Maximum”.
I have studied Quaternary Science (or Quaternary Geology as it is called in Sweden) and I am perfectly comfortable with this usage.
And it is the Quaternary/Pleistocene that has lasted for 2.5 million years. The current Glacial Epoch started with the Oi-1 glaciation about 35 million years ago.
Ice Ages (or Ice Houses) consist of glaciations and interglacials. Within the glaciations are colder stadials and warmer interstadials. The Last Glacial Maximum was the longest sustained cold interval of the last glaciation.
“Ice Age” can mean either the past 35 million years (and previous intervals with a lot of ice on earth), the past 2.6 million years (the Quaternary Period and Pleistocene and Holocene Epochs), or just the times during the Pleistocene in which ice sheets spread over North America and Eurasia as well as Greenland.
Even geologists don’t use these terms always to mean the same thing, although MIS, glaciation, interglacial, stadial and interstadial are pretty well defined technically. But as Javier argues, even “interglacials” might have to be redefined.
IMO, earth has been in an Ice House for 35 million years, since Antarctic ice sheets formed, but in an Ice Age just sine the Pleistocene glaciations commenced. The Ordovician had at least an ice age and the Carboniferous and Permian experienced a long Ice House.
It’s usually easy to tell from context what is meant by “ice age” and “glaciation”. I use glacial or ice sheet advance or glacial phase if there is any possibility of being misunderstood.
Now that yo’all have edumacated the dummies on what an “ice age” is …….. why don’tju edumacate the dummies on what a “greenhouse” is.
Samuel:
David, and what is the “greenhouse” gas therein, …… NG, propane or just random bursts of flatulence?
Are you possibly confusing who said what?
Pop,
By “you”, meaning jlk103144, who addresses Mr. Watts.
Indeed, AW did not write what jlk103144 claims.
And the question is — Why?
“…distinct ridges bulldozed into the seabed by glaciers…”
Perhaps like the glacial evidence in the sea floor off the southern US east coast?
“southern US east coast”
And, that too, is near South Georgia. I think I’ll raise a glass to the coincidence.
“Life must have really only survived at the edges, at and beyond the ice margins.” right there is no sea life under the Arctic ice cap …
“Alarming recession,” there’s the money shot. Co-author Duanne White sounds like a card-carrying alarmist.
K
I look for detail and data within article. Words associated with alarmism are like water off a ducks back, no emotion.
The study is valid and of real value. Many researchers have had to work and survive during a very difficult time. If they have to use those words to progress real understanding, who cares.
First, they note how hard the glacial advance must have been on life, then get worried that retreating glaciers threaten something or other.
How many times do the co-authors have to genuflect before the climate change gods when it comes to a story that has absolutely nothing to do with any recent/current events?
Always, no exception.
MichealJ: They are simply citing established science.
That South Georgia was glaciated should come as no surprise.
Even South America had an ice sheet during the LGM. It takes its name from a big lake in southern Chile, near Puerto Montt, which is located on a sound, a sunken valley excavated by a glacial lobe, much like Puget Sound in Washington State.
https://en.wikipedia.org/wiki/Patagonian_Ice_Sheet
New Zealand also.
Glaciers even in the highlands of Tasmania.
But oddly enough the Falkland islands don’t seem to have ever been glaciated.
The real star of this show is the bipolar seesaw. The article is about a specific episode during the process of deglaciation from the last glacial maximum which began with slow warming in the southern ocean around Antarctica 20k years ago. About 15k years ago Antarctic warming went into reverse for a couple of thousand years, an event called the Antarctic Cold Reversal. At the same time the episode of abrupt warming of the NH took place due to a strong excursion of the AMOC and Gulf Stream. This event was the Bolling-Alerod NH warming. The Gulf Stream warms the North Atlantic by stealing ocean heat from the SH in the Atlantic, a process known as heat piracy and which takes place, appropriately, in the vicinity of the Caribbean.
The Bolling-Alerod warming was a D-O event, the last one during the recent glacial period. Immediately after the B-A there followed cooling as the AMOC petered out and this led to the retro-cold period in the NH that is called the Younger Dryas. Due to the operation of the bipolar seesaw however, NH cooling in the NH was accompanied by SH warming, as the Antarctic Cold Reversal was itself reversed and Antarctic and SH deglaciation warming resumed. South to north heat piracy declined as the AMOC died down and with it the Gulf Stream.
What triggered the B-A and simultaneously the Antarctic Cold Reversal was a huge ice sheet collapse in the slowly warming Antarctica 15k years ago. This released a large meltwater pulse into global ocean circulation which had the indirect effect of kick-starting the AMOC in the North Atlantic. And the AMOC was itself terminated – as always – by meltwater from Greenland interfering with formation and downwelling of cold North Atlantic deep water.
The article in question focuses mainly on this Antarctic Cold Reversal, a brief episode of reversal of deglaciation warming; not the previous glaciation ad a whole. It shows the strength of the bipolar seesaw.
see saw = conservation of energy
Of course it bloody well was. The south of New Zealand was glaciated for Christ’s sake!
Glaciers in NW Nelson at the top of the South Island and even in the Tararua Ranges in the North Island during the LGM. Still small glaciers in Mt Ruapehu in the Central North Island even now.
See! The ice is melting.
We’re doomed.
Do you know how much the ice-albedo feedback is contributing to climate change?
About 25% of CO2.
K. Pistone, I. Eisenman, and V. Ramanathan (2014). Observational determination of albedo decrease caused by vanishing Arctic sea ice. Proc Natl Acad Sci USA 111, 3322-3326.
http://eisenman.ucsd.edu/papers/Pistone-Eisenman-Ramanathan-2014.pdf
Shackleton, Worley and Crean had to cross South Georgia’s glaciated mountains to reach the whaling station from the isolated beach where they had made landfall, after their 800 mile crossing from Elephant Island that was the final part of the incredible bid for survival after their stranding in Antarctica in 1914. Shackleton’s survival epic is increasingly recognised and maybe the most remarkable feat of survival in known history. Of all the dangers they faced on the ice and sea and in freezing gales, their trial on the Montains of South Georgia was probably the most dangerous, where the group’s three leaders came closest to death. Equipped only for a one-day quick crossing of the mountains, they were stranded on a glacial ridge as night approached and with it probable death from cold. Shackleton understood the stakes and chose to “slide”. They found a snow covered slope and without seeing what lay further down – rocks, cliffs etc, they just tobbogganed downhill blindly hoping for the best. They rode their luck and got away with it – reaching the other side of the ridge safely and walking to the whaling station and eventual rescue. This is all recorded in the book “Endurance” by Albert Lansing and I understand another film, “Ice” is now being made of this adventure.
http://www.goodreads.com/book/show/139069.Endurance
Shackleton was probably mightily pleased to find that South Georgia was NOT glaciated when he arrived.
Indeed – they had not been away quite that long!
Shackleton died from a heart attack in Grytviken on a subsequent expedition and is buried in the Norwegian cemetery there.
In a way he was lucky. If he had died in England and been buried in Westminster Abbey, who would have known or cared today?
While almost everybody who has visited South Georgia for the last 100 years (including yours truly) have visited Shackleton’s grave to pay homage one of the greatest polar explorers ever.
South Georgia will be added to my bucket list
More interesting reading – Antarctica used to be a tropical paradise https://www.nap.edu/read/12168/chapter/4#22
So you agree that the Antarctic climate can be highly variable….
Never said it wasn’t – but it’s not going to change any time soon. Not as long as the tilt of the planet and the orbit remains the same.
Earth’s Milankovitch factor are right now changing by -0.003 W/m2/yr.
That’s right — negative. Implying cooling.
Instead we’re warming. Fast.
crackers
indeed warming exactly as fast as we have already 19 times during the Holocene.
And the current warming number 20 is special because…?
I’d like to see the data showing that the Holocene has warmed 19 times before at today’s rate (+0.17 C/decade for the last 30 years, according to NOAA and other groups).
WUWT, thank you; occasionally you come up with a valuable tit-bit. This is another tell-tale of something science has not yet come to terms with. That the earth’s tilt changes beyond the 22-24 deg range, and that change is abrupt (how abrupt is ??? but definitely less than decades). There is a need to check the basics.
melitamegalithic, what’s the evidence the tilt angle changes abruptly?
The calendars tell the date by following sunrise point on horizon over the year. The angle equinox to solstice, at latitude 35.8 deg N, tells the earth obliquity at that time. One later calendar started at 18deg (same as most of the earlier ones) sometime post 3000bce, then was modified to today’s obliquity. In fact it corroborates Dodwell’s claim of an obliquity change at 2345bce. There are earlier changes, all abrupt, with tell-tales of events that appear in proxies. You may find all recent findings in the Facebook page set up update my earlier publication. Link to here, there is a lot of material on proxies and how the calendars work::: https://www.facebook.com/melitamegalithic/
All changes seen from archaeology are confirmed/corroborated in proxies. There are several obliquity swings recorded in their design. (I have also tested the design in model form and it is very precise).
So you’re relying on calendars that are thousands of years old, instead of modern astronomy.
Why would the tilt angle change abruptly? What would cause that?
crackers345, this may help you with your question. Warming polar regions but simultaneous cooling in tropics. All seismic events. Megalithic calendar design during that period records earth tilt. https://www.facebook.com/melitamegalithic/photos/a.689655294542612.1073741862.430211163820361/689655301209278/?type=3&theater
crackers345, no reply button after your question above. An answer is here. Note the subject of this thread. We rely many times on proxy evidence, because there are no direct answers to questions. The calendars happen to point to a clear answer to something the effect of which appears in many proxies, and in astronomical observation of the past. It has been noticed that ancient measurements of obliquity do not match modern calculations for that age. That has never been explained (except some attempts to deny, which is wrong). The ancient calendars tell clearly otherwise.
As to why the abrupt change, ????,; however, first it has to be acknowledged. Present thinking deny it can happen, the result of a wrong assumption from the past.