Via a Euerekalert press release
Past climate of the northern Antarctic Peninsular informs global warming debate
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  IMAGE: The American icebreaker RV/IB Nathanial B. Palmer is shown off the South Shetland Islands. The drilling rig is clearly seen on the rear deck.Click here for more information. |
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The seriousness of current global warming is underlined by a reconstruction of climate at Maxwell Bay in the South Shetland Islands of the Antarctic Peninsula over approximately the last 14,000 years, which appears to show that the current warming and widespread loss of glacial ice are unprecedented.
“At no time during the last 14 thousand years was there a period of climate warming and loss of ice as large and regionally synchronous as that we are now witnessing in the Antarctic Peninsula,” says team member Dr Steve Bohaty of the National Oceanography Centre, Southampton (NOCS), home of the University of Southampton’s School of Ocean and Earth Science (SOES).”
The findings are based on a detailed analysis of the thickest Holocene sediment core yet drilled in the Antarctic Peninsula. “By studying the climate history of the past and identifying causes of these changes, we are better placed to evaluate current climate change and its impacts in the Antarctic,” says Dr Bohaty.
As part of a 2005 research cruise aboard the American icebreaker RV/IB Nathanial B. Palmer, the scientists drilled down through the sediments at Maxwell Bay, a fjord at the northwest tip of the Antarctic Peninsula. They drilled down as far as the bedrock, obtaining a nearly complete 108.3-metre sediment core.
Back in the lab, they performed a battery of detailed sedimentological and geochemical analyses on the core. Radiocarbon dating showed that the oldest sediments at the bottom of the core were deposited between 14.1 and 14.8 thousand years ago, and sedimentation rates at the site varied from 0.7 to around 30 milimetres a year through the Holocene; that is, the geological period that began around 11,700 years ago, continuing to the present.
They conclude that ice was grounded in the fjord during the Last Glacial Maximum – the height of the last ice age – and eroded older sediments from the fjord. Later, the grounded ice retreated, leaving a permanent floating ice canopy.
The evidence points to a period of rapid glacial retreat from 10.1 to 8.2 thousand years ago, followed by a period of reduced sea-ice cover and warm water conditions occurring between 8.2 and 5.9 thousand years ago. An important finding of the study is that the mid-Holocene warming interval does not appear to have occurred synchronously throughout the region, and its timing and duration was most likely influenced at different sites by local oceanographic controls, as well as physical geography.
Following the mid-Holocene warming interval, the climate gradually cooled over the next three thousand years or so, resulting in more extensive sea-ice cover in the bay. But the researchers find no evidence that the ice advanced in Maxwell Bay during the so-called Little Ice Age in the sixteenth to mid-nineteenth century.
The Antarctic Peninsula area has warmed 3 °C in the past five decades, with increased rainfall and a widespread retreat of glaciers. “Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
The study was supported by the US National Science Foundation Office of Polar Programs.
The authors are: K. T. Milliken and J. B. Anderson (Rice University), J.S. Wellner (University of Houston), S.M. Bohaty (NOCS/SOES) and P.L. Manley (Middlebury College, Vermont).
Publication:
Milliken, K. T., et al. High-resolution Holocene climate record from Maxwell Bay, South Shetland Islands, Antarctica. Geological Society of America Bulletin 121, 1711-1725 (2009).
http://gsabulletin.gsapubs.org/content/121/11-12/1711
“Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
“Alarmist climate hysteria linked to research funding are an obvious culprit for the observed ridiculous statements in this research,” says everyone with an iota of common sense.
“the current warming and widespread loss of glacial ice are unprecedented”
I am sick and tired of it.
Let’s send those scientist a letter of resignation.
What they are doing is all in support of the hockey stick graph.
Pathetic is it not?
Sheesh. Where to begin?
I don’t know if this relevant,but it’s interesting.I would have liked to see some photos.
http://www.dailytelegraph.com.au/news/national/iceberg-a-big-surprise-for-aussie-scientist/story-e6freuzr-1225795243959
A HUGE iceberg has been spotted off Macquarie Island, halfway between Antarctica and Australia.
The iceberg, estimated to be 500m long and 50m high, was spotted about 8km north-west of the island by Australian Antarctic Division expeditioners this week.
Fur seal biologist Dean Miller was the first to see the iceberg while on his way to visit a seal colony at the island’s North Head.
“I’ve never seen anything like it – we looked out to the horizon and just saw this huge floating island of ice,” Dr Miller said on the AAD website.
“It was a monumental moment for me as it was the first iceberg I have seen.”
Glaciologist Neal Young said icebergs were a rare sight at Macquarie Island.
“This is the first I can recall being sighted from Macquarie Island for many, many years,” Dr Young said.
When all the stimulus funding for bogus AGW research ends, then these folks can say “It is worse then we thought” and they can turn into economists.
Jeremy (17:49:31) :
“Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
“Alarmist climate hysteria linked to research funding are an obvious culprit for the observed ridiculous statements in this research,” says everyone with an iota of common sense.
NOM !
Strange there’s no mention of the rest of the Antarctic……
Never mind that the Antarctic Peninsula only makes up a small percentage of the continent. I guess the extent of the build up of ice elswhere in Antarctica just gets in the way of a good story.
Sorry for the second post,but I found a photo
http://www.themercury.com.au/article/2009/11/07/108371_tasmania-news.html
I remember reading somewhere that due to its unique position- jutting out so far north into the Antarctic Ocean as it does. That the climate of the peninsula goes its own way and data from this small area of land cannot be extrapolated as representative of the climate of the rest (90%?) of Antarctica as a whole.
Also, this “science” sounds quite like the whole tree ring debacle in the way it was excecuted.
So, in conclusion, the Little Ice Age may not have affected the peninsula as much as the main body of Antarctica, therefore, this work cannot disprove the existence of the Little Ice Age.
More evidence of unprecedented warming from a single core… this sounds strangely familiar. Perhaps a few more cores from areas of the Antarctic further from the Starbucks at the peninsular bases would be useful. Maybe the Chinese expedition can increase the sample size. They seem willing to trek much further than the peninsular (relative) comfort zone.
http://english.sina.com/technology/p/2009/1010/276621.html
Noelene (18:01:15) :
Re: HUGE iceburg – Kewl!
Re: Is it unusual/Monumental/Never Before? No.
Huge Icebergs are common for a gigantic frozen continent with ice pinned to outlying islands….
“Sorry for the second post,but I found a photo
http://www.themercury.com.au/article/2009/11/07/108371_tasmania-news.html”
Talk about looking out of place! Great photo…
“‘Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,’ say the researchers.”
Isn’t this a roundabout way of conceding that there is no data or evidence to support the causal connection?
If that iceberg melts will the ocean swallow up the Maldieves?
Perhaps it needs to be towed to colder waters so it doesn’t melt.
Anyone who has ethically & competently looked into the details of Antarctic patterns knows the Antarctic Peninsula is not representative of the Antarctic as a whole, which appears to often be in anti-phase with much of the world with regard to temperatures on decadal timescales. Each study that is conducted ethically & competently contributes to an overall picture.
They must be getting desperate…surprised it took them this long to go for that one. Wouldn’t take much to considering how flat the trends have been in Antarctica.
http://s852.photobucket.com/albums/ab89/etregembo/?action=view¤t=Vostok-2.jpg
I think there biggest disappointment must have been the Greenland ice cores…not something you’d generally want to compare today’s temperatures with (which is you don’t see it anywhere)…
http://s852.photobucket.com/albums/ab89/etregembo/?action=view¤t=GISP2-Zoom.jpg
I believe today’s temp is <1°C greater than the last datapoint in the dataset.
I wonder where the temperature should be going? Assuming the last three cycles would be followed by a fourth…ending ~200yrs from now (or is it done now)? We'll see…
So, they’ve managed to deal a death blow to the Roman Optimum, The Medieval Warm Period and the Little Ice Age, and have determined that ” An important finding of the study is that the mid-Holocene warming interval does not appear to have occurred synchronously throughout the region” …. all with one core!
The wonders of modern science.
That would be a nice place for a tent and a grill. Cookout time!
I think this may be a measure of the desperation to get Copenhagen passed. To this observer, there has been an exponential increase in the junk science supporting the AGW meme this year, starting with Steig in January. My observations do not constitute a scientific study, just my gut feeling.
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How deep was the water at the drill sites? If it were not extremely deep ice berg keels could have disturbed and plowed the sediment in unpredictable ways.
How many different conditions would cause the glaciers to recede? Warming, and perhaps long periods of low precipitation, or perhaps volcanic activity.
How are they determining the age, seasonal layer deposits? Shifting tides will lay down separate distinctive layers.
Sometimes near shore sediment cores are about as reliable as tree rings in recording climate conditions.
I could not glean enough reliable data from this article to gain any confidence in their conclusions. It would appear they knew the answers and were looking for evidence in the cherry tree.
The Antarctic Peninsula area has warmed 3 °C in the past five decades, with increased rainfall and a widespread retreat of glaciers. “Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
‘An obvious culprit’ means we are speculating without any evidence to support the speculation.
‘Atmospheric warming trends linked to global climate change’ is the new science so successfully pioneered by climate scientists where cause and effect have been dispensed with. Now everything is ‘linked’ by mysterious, undefined and un-named mechanisms.
They talk vaguely of a 3C temperature increase on the Antarctic Peninsula, which is 120 kilometers away from the South Shetland Islands. I’d be interested to see if temperature changes on the islands are anywhere close to that. I doubt it.
Where did they conclude from evidence in the sediment that the last century was unprecedented when the Holocene Optimum was shown as warmer than now???
“Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
Interesting. Gone from their conclusion is the phrase “man-made greenhouse gasses” or “anthropogenic”.
Now it is just “global climate change.”
DUH. Get used to it!
Just as your ice cores show: Climate CHANGES…..that’s what it does.
Chris
Norfolk, VA, USA
“Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes.”
Climate change is responsible for climate change. The sentence is a tautology, but notice how he slips in the otherwise meaningless modifier “atmospheric” (when the earth’s heat content is actually contained in the oceans). This is an obvious signal for what he lacks the evidence to actually say: that warming is caused by CO2. So the dirtbag insinuates.