Ice Cores Unlock Climate Secrets

BBC ^ | 6-9-2004 | Julianna Kettlewell

[FreedomCalls]

Looks like we have about 18,000 years more of good weather, huh?

That depends on if Al Gore sees his shadow.

[squarebarb]

Nope. But looking forward to the waving gassy brown posts. You could do...um...seaweed?

[PA Engineer]

"All interglacials are slightly different, but we believe Termination V is the most similar to our own," says chief author of the new study, Eric Wolff, at the British Antarctic Survey in Cambridge, UK. It mirrors the pattern of solar warming between seasons and at different latitudes that are caused by fluctuations in the Earth's orbit known as the Milankovitch cycles.

Thanks for the ping and the post! This is absolutely fascinating. I am sure it will mean nothing to the GW crowd who still believe in sacrificing virgins to appease the volcano gods. ;-)

[rightofrush]

bttt

[Old Professer]

This could take awhile to analyze; each foot represents 40.4 years.

[blam]

"This could take awhile to analyze; each foot represents 40.4 years."

Good info, thanks.

[BenLurkin]

Very interesting. "Tiny bubbles of ancient air are locked in the ice"

What will analysis of the air show I wonder?

[blam]

"What will analysis of the air show I wonder?"

They're hoping it will represent the earth's air over this period of time.

[BenLurkin]

What I mean is: will it contain a different mix of gases? Will it carry microorganisms? Things like that.

[blam]

"What I mean is: will it contain a different mix of gases? Will it carry microorganisms? Things like that.

Different mixes of gasses for sure. Microorganisms hmmm, don't know.

I recently read that DNA was obtained from a 240 million year old bacteria that was found trapped in a salt crystal.

[Shryke]

Ahem. WHY wasn't I pinged to this? Really, Patrick. And Vade, my good man, why no PH ping? Has the recent reduction in Creats caused a lessening of the vigil?

[Doctor Stochastic]

Ice cores are layered. You can look it up. There are various methods. Besides counting visually (and comparing to annulary tree growth rings), there is a difference in pH between summer and winter depositions so that electrical conductivity can be used. This is good to about 1 or 2 mm. Also one can analyze the H vs D and O16 vs O18 ratios to get temperatures. Various metal residues (Be for example) can be used to date certain parts against known dates. Cores can also be checked with coral cross-sections as well as cores from other parts of the world (Greenland, Siberia, Antarctica.)

There are articles in the usual journals.

[Kay Ludlow]

Ice cores are layered

I understand that completely. My question is how compressed are the layers after the weight of 100,000 years of snow have been on top of them? I would not think that individual years could be distinguished, just broader patterns - more like earth cores than like tree rings. Dig down in the earth and you can see the eons, but only very rarely was there a specific layer that can be certain to have formed in one year (like a volcanic layer). Instead you can see how the earth changed in different periods for sure, but can't determine specific years because of the compression.

[PatrickHenry]

WHY wasn't I pinged to this? Really, Patrick. And Vade, my good man, why no PH ping?

I depend on my far-flung network of operatives to alert me when a likely thread makes its appearance. If something somes to my attention too late, I generally let it go. As here.

[Doctor Stochastic]

I think they're still working on the problem from the little I've read. The electrical conductivity was a new one for me. They put electrodes on opposite sides of a core and measure the conductivity. Because the pH is different between summer and winter (which I also didn't know), they can find a yearly boundary. This should only be limited by the fineness of the probes.

[Shryke]

far-flung network of operatives

I think it's time to start using the word 'cabal'. Much more fun.

[Doctor Stochastic]

When will the cabal be promoted to junta?

I once had to explain to a Communist (SWP-USA) that I was to be referred to as a "lackey" because I had been promoted from "running dog."

The Darwintern continues. (Still haven't been able to obtain that Bilderberger grant.)

[Shryke]

Hahaha. I think we need to aquire a compound, or at least a base of operations, before we can escalate to junta. On the other hand, what the hell do I know? I'm feeling very Kerry this morning....let's use both.

[gatex]

"...My question is how compressed are the layers after the weight of 100,000 years of snow have been on top of them? ..."

Good observation

Here are some data from the Vostok Ice Cores --- Vostok ice data

BP = before present.

" Depth, m - Yr BP - mean age-- Co2, ppmv

3120.61--- 324711 --322827--- 288.4
3123.51 ---325400-- 323485 ---298.7
3129.91--- 327237 --324991--- 285.8 "

Looks to me that the largest CO2 number that I noticed is an average of several hundred years.

The current 370 ppmv CO2 is 24 percent higher than an average of several hundred years --- seems to me that to get an average of 298.7 over several hundred years, some of the data had to be higher, --- and thus, much closer to current data.

[VadeRetro]

The way I categorize this stuff, this is a "blam" thread, not a crevo thread. "Blam" threads are for arguing whether Atlantis had anything to do with Lemuria and were the Celts the Lost Tribes of Israel.