New technique suggests Medieval Warm Period made it to Antarctica

May 01, 2012

Scientists have developed a new method of reconstructing past climates that uses the water locked inside crystals in seabed sediment to shed light on the history of the Antarctic.

The technique's first results suggest that recent fluctuations for which there's never been much evidence outside the northern hemisphere may have affected more of the globe.

Much more research is needed, but the implication is that the unusually warm and cold periods known as the (MWP) and Little Ice Age (LIA) were felt as far south as the . If this turns out to be true, scientists' understanding of how the has changed over the last few hundred years may need to be revised.

'Our work suggests that there have been recent climate oscillations on the Antarctic peninsula that seem to coincide with these well-known ,' says Professor Rosalind Rickaby, a biogeochemist at the University of Oxford, who led the research. 'It's a further indication that these events had a footprint in the southern hemisphere - at the moment it's hard to say more than that.'

An international team of scientists worked with cores of the mud from the sea floor, taken on a recent Antarctic research cruise. At intervals within each core they found crystals of ikaite - an unusual variant of calcium carbonate, more commonly found as limestone. Ikaite forms only in very cold conditions and fresh crystals have only recently become the object of scientific attention.

As it forms, ikaite traps molecules of the surrounding water within its crystal structure. The researchers devised a way to recover this water, and then analysed its ratio of two different variants of oxygen, known as isotopes.

This provides information about the balance of freshwater and saltwater flowing into the area the crystal formed in. This can in turn be used to work out how quickly the far above was melting, and hence how warm the climate was at the time. By dating the mud the crystals are buried in, scientists can accurately match the climate signals they contain to records elsewhere. They estimate the technique's margin of error for dating in this area is about 60 years.

Rickaby had already come up with the idea of using these crystals to reconstruct past climates, but the chance to put it into practice came only a few years ago when she was invited to join a US Antarctic Program cruise and collect sediment cores in areas that looked promising for ikaite formation.

Unfortunately only one core turned out to yield significant numbers of ikaite crystals, in the Firth of Tay at the far northeast of the Antarctic Peninsula. And even here there weren't many. 'We only found 11 ikaite crystals over 2000 years. The sediments here accumulated quickly, at about 2mm per year, but the crystals are about two metres apart, so the study doesn't give us very high resolution,' Rickaby says.

Still, in time more crystals should be found from around the Antarctic. And the ikaite technique has major advantages. Before now, scientists have tried to work with the water that's trapped within sediment itself. But because this isn't completely sealed from the outside environment, its climate information fades over time. This means it can only be used to study dramatic environmental shifts like the end of the last ice age. By contrast, the ikaite record is far more sensitive and can illuminate much subtler changes.

Rickaby says much more study of Antarctic ikaite is needed before we can be sure of the findings. 'Our study only looked at one place, and the results are a long way from being definitive - it's far too early to draw broad conclusions from this,' she says.

If it's confirmed that the MWP and LIA did reach the Antarctic, there will be important implications for our overall understanding of climate change that may well need to be taken into account in the next report from the United Nations Intergovernmental Report on Climate Change, expected in 2014, but these will be complex and not easily summarised in headlines.

In the meantime the ikaite technique could be an important addition to the arsenal of ways to investigate ancient climates. More recently, Rickaby has been coring in the Zaire Fan sediments off the west coast of Africa in search of much older ikaite crystals - perhaps from as much as 50,000 years ago. She adds that glendonites, the mineral into which ikaite eventually decays, also preserves climate records, and could potentially illuminate conditions going back hundreds of millions of years.

The paper appears in Earth and Planetary Science Letters.

Explore further: Jeju Island is a live volcano, study reveals

More information: Earth and Planetary Science Letters (2012) pp.108-115. dx.doi.org/10.1016/j.epsl.2012.01.036

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Lurker2358
1.4 / 5 (10) May 01, 2012
The Medieval warm period was cause by a spike in radiation from the Crab Pulsar Supernova.

There is no other viable candidate.

Sure, it only amounts to a couple milliwatts per square meter, but keep that up for a few years in visible light, and several decades in invisible spectra, and it'll start to add up...
StarGazer2011
1.9 / 5 (13) May 01, 2012
But hold on ... if the MWP was globally warmer than now, does that mean 1978-1998 0.7C warming wasn't unprecedented?
Wasn't the MWP considered global in 1996, and only downgraded to suit the alarmist agenda for the IPCC 2004 report?
I'm sure this science will be denied by the CAGW zealots; they only like science which confirms their religious prejudices.
PeterD
2.6 / 5 (10) May 01, 2012
Old news, and whatever caused it, it wasn't us.
thermodynamics
4.8 / 5 (10) May 01, 2012
Sigh...

Of course the loons are already out.

First, this is good research. Second, the reporter is quick to point out: "Unfortunately only one core turned out to yield significant numbers of ikaite crystals, in the Firth of Tay at the far northeast of the Antarctic Peninsula. And even here there weren't many. 'We only found 11 ikaite crystals over 2000 years."

For those of you who can't read and don't understand statistics, this can be interpreted as concrete evidence for your agenda.

For those who can read and understand statistics, this is a potentially valuable tool that has an interesting result but terrible statistics. So, someone needs to confirm. Let's stand by and wait for confirmation. Or, let the flame wars begin!
NotParker
1.5 / 5 (15) May 01, 2012
But hold on ... if the MWP was globally warmer than now, does that mean 1978-1998 0.7C warming wasn't unprecedented?


Correct.

http://www.co2sci...tion.php
NotParker
1.6 / 5 (14) May 02, 2012

Of course the loons are already out.


There are already hundreds of papers that show a very warm MWP:

http://www.co2sci...mwpp.php

Some already reference Antarctica:

http://www.co2sci...tica.php

Why call people loons ... just because the MWP existed?

Aren't the loons the ones who deny it existed?
Parsec
3.9 / 5 (7) May 02, 2012
But hold on ... if the MWP was globally warmer than now, does that mean 1978-1998 0.7C warming wasn't unprecedented?
Wasn't the MWP considered global in 1996, and only downgraded to suit the alarmist agenda for the IPCC 2004 report?
I'm sure this science will be denied by the CAGW zealots; they only like science which confirms their religious prejudices.

The article, and no one except perhaps the denialists have said anything about the MWP being warmer than today. It was warmer than the mean, and the little ice age was cooler than the mean.

The last dozen or so years have seen rather dramatic rises in temp. There is no evidence at all that the MWP occurred suddenly or in fact was that profound.
Vendicar_Decarian
3.7 / 5 (6) May 02, 2012
And if black were yellow then bananas would never ripen.

"But hold on ... if the MWP was globally warmer than now..." - StarTard

https://docs.goog...vbUxuNGc
Vendicar_Decarian
3.9 / 5 (7) May 02, 2012
Nope.

"Wasn't the MWP considered global in 1996" - StarTard

But feel free to conspiratoralize.
Egleton
4.6 / 5 (9) May 02, 2012
I always wanted to be a famous climate scientist, but alas I am but a simple Electrician.
So what is a poor boy to do?
Well for one he could listen to famous climate scientists. Always go first class, I say.
It is how I don't waste time and get by.

But then again, perhaps it is a conspiracy. Perhaps the Bureau of Meteorology of Australia is in cahoots with Al Gore to defraud me of my millions.

eer. "First class?" So what am I doing on this forum?
NotParker
1.6 / 5 (13) May 02, 2012

The last dozen or so years have seen rather dramatic rises in temp. There is no evidence at all that the MWP occurred suddenly or in fact was that profound.


A dramatic drop actually since globally it is around .6C colder than 1998.

"Changes in the location of the edge of the Amery Ice Shelf were inferred from measurements of biogenic opal, absolute diatom abundance and the abundance of Fragilariopsis curta found in sediments retrieved from beneath the ice shelf at a point that is currently 80 km from land's edge. The MWP at ca. 750 14C yr BP was likely warmer than at any time during the CWP."

http://www.co2sci...helf.php
Vendicar_Decarian
3.5 / 5 (8) May 02, 2012
Ah, this would be the Magic ParkerTard temperature drop that isn't recorded on any temperature data set.

http://www.woodfo...98/trend

"A dramatic drop actually since globally it is around .6C colder than 1998." - ParkerTard

You need to see a psychiatrist Tard Boy.
Vendicar_Decarian
4.1 / 5 (9) May 02, 2012
Maybe on planet Metaluna. But here on earth the largely regional warming known as the MWP was dramatically cooler than today.

"The MWP at ca. 750 14C yr BP was likely warmer than at any time during the CWP." - ParkerTard

Here is a nice plot that illustrates the extent of your lie.

https://docs.goog...vbUxuNGc

You need to see a psychiatrist Tard Boy.
NotParker
1.6 / 5 (14) May 02, 2012
Maybe on planet Metaluna.


On earth the MWP was not regional and was warmer.

But keep up that AGW cult chant ..... it makes you look dumber than usual. Which is amazing.

I think it was pretty cool to find the ice had retreated 80km from where it is today.

Another:

"This work yielded, in Hall's words, "information on times in the past when climate in the South Shetland Islands must have been as warm as or warmer than today,"

http://www.co2sci...ecap.php
NotParker
1.3 / 5 (13) May 02, 2012
"A dramatic drop actually since globally it is around .6C colder than 1998."

http://www.drroys...2012.png

March 2012 = .11C anomaly from 30 year average

1998 it hit .66C.

Of course in 2008 it hit -.3C ... it wasn't that cold even in 1979.
NotParker
1.3 / 5 (13) May 02, 2012
Ah, this would be the Magic ParkerTard temperature drop that isn't recorded on any temperature data set.


HADCRUT3.

1998 = .75C
2008 = .05C

A .7C drop

http://www.woodfo...rom:1997

A drop of .55C to the start of 2012.

HADCRUT4 is the dataset they fabricated because people kept pointing out the .7C drop in HADCRUT3.
NotParker
1.3 / 5 (12) May 02, 2012
Ah, this would be the Magic ParkerTard temperature drop that isn't recorded on any temperature data set.


HADCRUT3.

1998 = .75C
2008 = .05C

A .7C drop

http://www.woodfo...rom:1997

A drop of .55C to the start of 2012.

HADCRUT4 is the dataset they fabricated because people kept pointing out the .7C drop in HADCRUT3.


It is colder than 1944 right now.

http://i47.tinypi...5ykp.jpg
Vendicar_Decarian
4.4 / 5 (7) May 02, 2012
It certainly looks to be reagional.

"On earth the MWP was not regional and was warmer." - ParkerTard

http://cdn.intech..._age.pdf

"MWP is thought to have been most prominent in the Northern Hemisphere, yet even there, the warmest period during the MWP is thought to have been 0.35C cooler than the average temperature from 1970-2000."

http://www.thegai...-period/

Get mental help Parker Tard. Do it before you hurt someone or yourself.
Vendicar_Decarian
4.5 / 5 (8) May 02, 2012
Sorry Tard Boy, but all you have done is to take the warmest month in 1998 and the coldest month in 2008 and then draw a line between the two and claim that this is the overall temperature trend.

"HADCRUT3. 1998 = .75C 2008 = .05C" = ParkerTard

With the same method we could start at 1997 and end at 2007 and get a trend of 0.6'C per decade.

If you can get dramatically different values based on slightly different endpoints then your technique is invalid.

You have been told this dozens of times.

Yet you persist on using the same flawed reasoning.

You are mentally ill. Get help.

Vendicar_Decarian
4.4 / 5 (7) May 02, 2012
Odd how your own source shows an increase in global average temperature of 0.15'C since 1998 and yet in your very next post you claim that there has been a drop of 0.6'C over the same period.

"March 2012 = .11C anomaly from 30 year average" - ParkerTard

You are mentally ill Parker Tard. You need to see a psychiatrist.
Vendicar_Decarian
4.3 / 5 (6) May 02, 2012
So somewhere on earth there was someplace that at one time had a microclimate temperature that was warmer than today.

"information on times in the past when climate in the South Shetland Islands must have been as warm as or warmer than today," - ParkerTard

Wow, now that is entirely mindless.

You need psychiatric treatment ParkerTard. Get help.

NotParker
1 / 5 (9) May 02, 2012
So somewhere on earth there was someplace that at one time had a microclimate temperature that was warmer than today.


During 1944 the whole globe was warmer than the globe is today.

http://i47.tinypi...5ykp.jpg
NotParker
1.3 / 5 (12) May 02, 2012

HADCRUT3. 1998 = .75C 2008 = .05C


Yes. A .7C drop in 10 years.

And it is still colder than 1944.

http://i47.tinypi...5ykp.jpg

NotParker
1.3 / 5 (12) May 02, 2012
Odd how your own source shows an increase in global average temperature of 0.15'C since 1998


UAH 1998 = 0.66C
UAH 2008 = -.3C

.96C drop in 10 years.

UAH 2012 = .11C

Still at .55C LOWER than 1998.

.01C LOWER than 1983.

Feel free to check:

http://www.drroys...2012.png

Vendicar_Decarian
4.4 / 5 (7) May 02, 2012
Why is ParkerTard using a data set that is out of date? And why does he think that comparing a cherry picked maximum temp with todays temperature is in any way statistically valid?

Oh well....

Here is the most recent HadCrut dataset.

http://www.woodfo...rom:1948

"During 1944 the whole globe was warmer than the globe is today." - ParkerTard.

You are mentally ill ParkerTard. Go to the nearest hospital and tell them that you are suicidal.
Vendicar_Decarian
4.4 / 5 (7) May 02, 2012

Odd how your own source shows an increase in global average temperature of 0.15'C since 1998 and yet in your very next post you claim that there has been a drop of 0.6'C over the same period.

"Yes. A .7C drop in 10 years." - ParkerTard

You are mentally ill Parker Tard. You need to see a psychiatrist.
Vendicar_Decarian
4.4 / 5 (7) May 02, 2012
UAH doesn't measure sureface temperaturs Tard Boy.

"UAH 1998 = 0.66C
UAH 2008 = -.3C" - ParkerTard

Why does this UHA plot show emperatur risig by 0.1'C per decade?

http://www.woodfo...o:2010.2]http://www.woodfo...o:2010.2[/url]

http://www.woodfo...o:2010.2]http://www.woodfo...o:2010.2[/url]

NotParker
1.7 / 5 (12) May 02, 2012
UAH 1998 = 0.66C
UAH 2008 = -.3C

.96C in 10 years.

You can whine and snivel all you want, but it won't help your case.
NotParker
1.3 / 5 (12) May 02, 2012
So somewhere on earth there was someplace that at one time had a microclimate temperature that was warmer than today.


During 1944 the whole globe was warmer than the globe is today.

http://i47.tinypi...5ykp.jpg

Vendicar_Decarian
3.3 / 5 (7) May 03, 2012
Why is ParkerTard using a data set that is out of date? And why does he think that comparing a cherry picked maximum temp with todays temperature is in any way statistically valid?

Oh well....

Here is the most recent HadCrut dataset.

http://www.woodfo...rom:1948

"During 1944 the whole globe was warmer than the globe is today." - ParkerTard.

You are mentally ill ParkerTard. Go to the nearest hospital and tell them that you are suicidal.
NotParker
1.4 / 5 (11) May 03, 2012
Why is ParkerTard using a data set that is out of date?


I say: "During 1944 the whole globe was warmer than the globe is today."

You claim that HADCRUT3 is out of date and try and use HADCRUT4 but do so in a dishonest way because:

1) HADCRUT4 isn't finished and doesn't go up to 2012

2) And you post a graph starting at 1948 when I was discussing 1944.

VD = VeryDishonest and VeryDumb

It is colder than 1944 now.

http://i47.tinypi...5ykp.jpg
MandoZink
3.7 / 5 (3) May 05, 2012
Sorry Tard Boy, but all you have done is to take the warmest month in 1998 and the coldest month in 2008 and then draw a line between the two and claim that this is the overall temperature trend.

I still like this animated graph:
http://www.skepti..._500.gif