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Remote Lake May Be Treasure Trove of Climate Data
ScienceNOW Daily News ^ | 13 December 2007 | Phil Berardelli

Posted on 12/15/2007 3:43:24 PM PST by neverdem

Enlarge ImagePicture of Pingualuit Crater

The vault.
The sediments at the bottom of the lake in Northen Quebec's Pingualuit Crater hold unmatched clues to North America's climate record.

Credit: Robert Fréchette / ARK; (inset) University of Arkansas

SAN FRANCISCO, CALIFORNIA--A million years ago, a large meteorite smashed into what is now northern Quebec and created a crater that may become an unprecedented repository of data with which to study long-term climate change, researchers reported here this week at a meeting of the American Geophysical Union.

Canada and the northern United States are dotted with tens of thousands of lakes, most of them formed by meltwater at the end of the last ice age about 12,000 years ago. Sediments at the bottom of those lakes hold chemical and biological evidence of how the planet's climate has varied for even longer periods, over many ice ages and interglacial cycles, and how those variations have affected the local ecosystems. But almost all of these sediments have been bulldozed repeatedly by glaciers as the giant rivers of ice have advanced and retreated over the last 2 million years, scrambling the geological record.

Pingualuit Crater in northern Quebec seems to have escaped this fate. Its 3.7-kilometer-wide, nearly circular lake not only is deep enough--nearly 270 meters--to have avoided the glacial pummeling but also has remained sequestered from any other body of water during its entire history. So the sediment that has collected on the lake's bottom has preserved a pristine record of the climate and biological activity in the lake for more than a million years--much longer than any similar climate data source currently available. Until recently, however, the technology necessary to retrieve samples from the bottom, without disturbing the samples or contaminating the lake's ultraclear water, did not exist.

So, paleolimnologist Sonja Hausmann of the University of Arkansas, Fayetteville, and colleagues employed a new type of coring rig devised specifically for obtaining delicate samples. Last May, after trekking across the then-frozen lake on foot without the aid of potentially polluting snowmobiles or sled dogs, the team deployed the bottom-dwelling rig, which is suspended from a Kevlar cable, and spent 2 weeks carefully extracting cores from the top 10 meters of Pingualuit's estimated 150 meters of sediment. Those samples are beginning to provide a treasure trove of data going back at least 250,000 years.

"We think the samples span at least two [interglacial] cycles," Hausmann says. They include diatoms--microscopic algae whose silicate shells can provide exquisite historical portraits of the lake's water quality and climatic conditions--as well as trace metals and pollen that have fallen from the atmosphere. Other records can be compiled from sources such as the ice cores in Greenland and the sea beds, she says, but the Pingualuit cores are the only ones available from the North American land that contain the skeletal remains of climate-sensitive algae.

"Collecting this core was no small endeavor," says paleolimnologist John Smol of Queen's University in Kingston, Canada. "Many of us had previously assumed that the last Ice Age had obliterated older sediment records," he says, but Pingualuit's cores show that "there is a remarkable history book still present."

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TOPICS: Canada; Culture/Society; News/Current Events
KEYWORDS: bolide; canada; catastrophism; climatechange; globalwarming; godsgravesglyphs; impact; quebec; science; stalactites; stalagmites
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The second link is a pdf link. This impact crater's sediment study may turn out to be very interesting, IMHO.
1 posted on 12/15/2007 3:43:29 PM PST by neverdem
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To: neverdem
I bet that it shows that Earth’s climate has warmed, and cooled thousands of times over the last million years. With man, without man, with dinosaurs, without dinosaurs, with unicorns, without unicorns. One thing that does not happen is that the earth does not change.
2 posted on 12/15/2007 3:47:21 PM PST by fhayek
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To: xcamel; cogitator; Tolerance Sucks Rocks

CC/GW potential seems very interesting.


3 posted on 12/15/2007 3:47:28 PM PST by neverdem (Call talk radio. We need a Constitutional Amendment for Congressional term limits. Let's Roll!)
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To: neverdem

Wow! What a cool lake!


4 posted on 12/15/2007 3:47:36 PM PST by Red_Devil 232 (VietVet - USMC All Ready On The Right? All Ready On The Left? All Ready On The Firing Line!)
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To: fhayek

You could ad. With AlGore, without AlGore, with the UN, without the UN.


5 posted on 12/15/2007 3:50:16 PM PST by Red_Devil 232 (VietVet - USMC All Ready On The Right? All Ready On The Left? All Ready On The Firing Line!)
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To: neverdem

I am surprised the global warmers don’t use the melting of the glaciers over the great lakes region just 14,000 years ago as evidence of man made global warming.


6 posted on 12/15/2007 3:56:50 PM PST by Always Right
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To: neverdem; OKSooner; honolulugal; Killing Time; Beowulf; Mr. Peabody; RW_Whacko; gruffwolf; ...

FReepmail me to get on or off


Click on POGW graphic for full GW rundown

New!!: Dr. John Ray's
GREENIE WATCH

Ping me if you find one I've missed.


Interesting..
7 posted on 12/15/2007 3:58:14 PM PST by xcamel (FDT/2008)
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To: neverdem

Maybe they can find the watch I lost way back when.


8 posted on 12/15/2007 3:59:42 PM PST by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: El Gato; Ernest_at_the_Beach; Robert A. Cook, PE; lepton; LadyDoc; jb6; tiamat; PGalt; Dianna; ...
Program Supplies Iraqi Veterinarians

Suing doctors for patients' acts

Woman catches fire during hemorrhoid operation

FReepmail me if you want on or off my health and science ping list.

9 posted on 12/15/2007 4:03:38 PM PST by neverdem (Call talk radio. We need a Constitutional Amendment for Congressional term limits. Let's Roll!)
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To: Always Right

Seems to me that glaciers would have pushed debris into the lake despite the fact they didn’t scour the bottom.


10 posted on 12/15/2007 4:08:50 PM PST by cripplecreek (Only one consistent conservative in this race and his name is Hunter.)
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To: neverdem

Wow I have dived and swam some blue holes before yet never seen such a large ice hole........but then we are talking global warming an AlGore......:o)

Isn’t this the same region that is infested with diamond mines ?


11 posted on 12/15/2007 4:10:59 PM PST by Squantos (Be polite. Be professional. But, have a plan to kill everyone you meet. )
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To: neverdem

That is a strange looking structure. Must have been buried in ice or sediment that disappeared when the glacier moved on.


12 posted on 12/15/2007 4:13:01 PM PST by RightWhale (anti-razors are pro-life)
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To: neverdem; xcamel; Reform Canada; GMMAC; Clive; exg; kanawa; conniew; backhoe; -YYZ-; ...

13 posted on 12/15/2007 4:14:45 PM PST by fanfan ("We don't start fights my friends, but we finish them, and never leave until our work is done."PMSH)
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To: Red_Devil 232
Wow! What a cool lake!

This one does kind of jump up and down yelling "I'm a meteorite impact!", doesn't it?

14 posted on 12/15/2007 4:16:25 PM PST by BlazingArizona
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To: neverdem
No doubt when the samples from this lake are examined, they will prove once and for all what Algore has been saying all along. There was never any climate change until people started burning stuff for selfish purposes. Now we’ve given the planet a goddamn fever.
15 posted on 12/15/2007 4:43:35 PM PST by Minn (Here is a realistic picture of the prophet: ----> ([: {()
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To: cripplecreek

That’s right, unless the crater was blown right through the ice and the lip was too substantial for the ice to climb over so it flowed around instead.


16 posted on 12/15/2007 4:46:09 PM PST by RightWhale (anti-razors are pro-life)
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To: RightWhale

The only other thing I can think of is pretty unlikely. The center of the outflow of glacial ice would need to be dead center over the lake.


17 posted on 12/15/2007 4:49:29 PM PST by cripplecreek (Only one consistent conservative in this race and his name is Hunter.)
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To: cripplecreek

Lakes here in the permafrost develop from sinkholes and fill in from dust and various living things. That crater appears to have been covered to considerable depth and the soil is now in Indiana after the glacier melted leaving bedrock. It has been exposed for much too short a time for erosion or vegetation to do serious work.


18 posted on 12/15/2007 4:54:31 PM PST by RightWhale (anti-razors are pro-life)
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To: fhayek

There have been about 8 major warm/cool cycles, but many smaller ones. The earth changes quite a lot. Every time a major volcano erupts [Tambora, Toba, Katmai], a meteor strikes like the dinosaurs 65 mya.


19 posted on 12/15/2007 5:05:19 PM PST by gleeaikin
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To: neverdem

Thanks for posting. I’ve never heard of the lake nor the coring project. It will be very interesting to see the results of their research.


20 posted on 12/15/2007 5:39:32 PM PST by ProtectOurFreedom
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