Catastrophic 'Lake Burst' Chills Climate

[phantom power]

The findings, reported in this week's edition of the international journal Science (30 June 2006), prove for the first time that sudden North American 'lake bursts' slowed ocean circulation and cooled the climate approximately 8200 years ago. The groundbreaking research increases our understanding of the complex link between ocean circulation and climate change and highlights the sensitivity of the Atlantic overturning circulation to freshwater forcing.

(...)

"The 8200-year-old event is the most recent abrupt climate change event and by far the most extreme cooling episode in the last 10,000 years, but up until now we knew comparatively little about its impact, if any, on the ocean circulation," said Dr Mark Chapman of the University of East Anglia. "Our records show a sequenced pattern of freshening and cooling of the North Atlantic sea surface and an associated change in the deep ocean circulation, all key factors that are involved in controlling the state of northern hemisphere climate."

Dr Ian Hall of Cardiff University said: "The impact of large-scale pulsed inputs of freshwater on ocean circulation and climate during the time of the last Ice Age are well documented, but our results clearly demonstrate that these sorts of abrupt reorganisations also can occur during periods of warm climate. These findings have important implications for future research because they aid our understanding of the magnitude of forcing involved in rapid climate changes and the mechanisms involved. This provides a useful target for assessing the models that are used to predict future patterns of climate change".

http://www.sciencedaily.com/releases/2006/06/060630100735.htm

[GreenPartyVoter]

1. I can't decide whether to prepare for global warming or an ice age

Either way i bet coastal Maine is screwed

[phantom power]

2. Prepare to be nomadic. The light-of-foot may survive.

[GreenPartyVoter]

6. The worst thing? The banks and insurance companies will

demand we continue to pay on our unlivable houses, as we have seen in the case of the Gulf after Rita and Katrina.

[dipsydoodle]

3. I have read that

we in England will get severely cold winters, substantial parts of the USA will become dustbowls but no mention of Maine. So I hope you'll be ok.:)

[GreenPartyVoter]

5. I think we will be first underwater then under ice

[depakid]

4. Interesting- never made that connection before

but it makes complete sense.

I wonder what types kinds of evidence of climate change might be associated with the Lake Missoula floods?

* Glacial Lake Missoula was as big as Lakes Erie and Ontario combined.

* The flood waters ran with the force equal to 60 Amazon Rivers.

* Car-sized boulders embedded in ice floated some 500 miles; they can still be seen today!



The Lake Missoula Flood occurred when Glacial Lake Missoula in northwest Montana broke through its ice dam in northern Idaho and drained down the Columbia River. The Lake Missoula Flood and other melting pulses from the Cordilleran Ice Sheet to the north swept a large area of Washington (after Waitt).

http://www.nwcreation.net/articles/missoulaflood.htm

[dipsydoodle]

9. I have seen a whole TV documentary

reference that subject here in the UK. Maybe you'll get on National Geographic whatever sometime. It's difficult to imagine the sheer force of all that rock and water escaping in such a short period time. I think the Grand Canyon was created in a similar way - rivers of rock. Thanks for the link - I've kept it.

[depakid]

16. There's also a NOVA documentary too!

It's pretty cool.

(Note that my previous link- while it has good geological descriptions, is also mired in "creation science" :eyes: )

Here's the NOVA link- it was buried down on page 2 of Google:

http://www.pbs.org/wgbh/nova/megaflood/

[dipsydoodle]

21. Megaflood

may have been the actual film that I recalled.

It's ok - I ignored the "creation science" bits in your first link.:)

[phantom power]

22. The Grand Canyon formed in a different way...

the land surrounding the Colorado river has been uplifted over a few million years. As the land uplifted, the Colorado gradually cut through it. Imagine a circular saw, and you take 2x4 and gradually raise it from underneath. The saw stays in one place, but cuts through the board as it raises.

[TallahasseeGrannie]

7. Is this the same principle

behing "The Day After Tomorrow"?

[Massacure]

10. Yes, but the Day After Tomorrow is exaggerated.

It may drop the climate 4-5 degrees and allow glaciers to advance south, but there won't be a continent sized hurricane which is 200 degrees below zero.

[Odin2005]

14. Yeah, it would take a few decades for the colling to really kich in.

The Day After Tommorow was based on some book written by a crackpot writer/radio-show host (cant remember his name off the top of my head) who though that the preserved mammoth carcasses were instantly frozen, there was a high-tech civilization during the hight of the last glacial period, and other nonsense.

[kestrel91316]

23. That would be Art Bell and Whitley Strieber.

Art is a pretty sharp guy. Not a crackpot IMHO. Whitley is a bit "out there".

[TallahasseeGrannie]

15. Okay

this is a good thing, then.

[Massacure]

18. Perhaps. 4 or 5 degrees is enough to cause havoc with species....

[TallahasseeGrannie]

19. Yes, but anything is better

than 200 degrees below hurricanes.

[dipsydoodle]

13. Broadly speaking - yes

If the Greenland ice cap melts the fresh water could disrupt the North Atlantic current which in turn could trigger an ice age. The increased sea level of the Atlantic wouldn't do low lying coastal areas either side of the ocean much good either.

This an old article : http://news.bbc.co.uk/1/hi/sci/tech/3607335.stm It's recenly been found that the melting is accelerating so the time scale in that link may be wrong.

Edit : better link here - http://www.bbc.co.uk/worldservice/learningenglish/newsenglish/witn/2006/01/060130_icecap.shtml

[Odin2005]

17. Not an ice age, but a Heinrich Event.

The confuguration of the Earth's orbit and tilt are not favorable for glacial conditions to sustain themseves, there would be a sharp cooling lasting for a few hundred years, but not a return to glaciation.

[dipsydoodle]

20. Always look on the bright side of life

but be aware of what's creeping up behind you.:)

[Gloria]

8. Wow, I just came home from An Inconvenient Truth--Al Gore

described this whole thing...about the huge, cool water area in eastern North America, how it blasted out into the ocean as the ice around the St Lawrence Seaway area gave way and how it changed the ocean engine ...and how Western Europe was in 900-1000 years of more ice age.....

BTW--Gore's lecture is incredible. I LEARNED so much!!!

[Gloria]

12. Here's the description from Gore's book....

"Around 10,000 years ago, something happened that the scientists are worried could happen again. When the last glacial ice sheet in N. America melted, it formed a giant pool of fresh water. The Great Lakes are the remnant of that huge freshwater lake, which was held in place on its eastern boundary by an enormous ice dam.

Then one day the ice dam broke and the fresh water rushed out into the N. Atlantic. When that unprecedented amount of fresh water tore open the St. Lawrendce River and flooded into the N. Atlantic, the pump began to turn itself off. The Gulf Stream virtually stopped. So Western Europe no longer received all of that heat from the evaporating Gulf Strea. Consequently, Europe went back into an ice age for another 900 to 1000 years. And the transition happened fairly quickly.

Some scientists are now seriously worried about the possibility of this phenomenon recurring. At Woods Hole Research Center, Dr. Ruth Curry is especially concerned about the rapid melting of ice in Greenland, which is adjacent to the are in which the pump operates."

[Odin2005]

11. IIRC, this was the final draining of Lake Agassiz

The first was a partial draining of the lake through the Rainy River (on the Minnesota-Ontario border) 12,000 years ago that triggered the Upper Dryas cooling event, which was even more severe than this 6,200 BC event. The later event was caused when the ice sheets retreated far enough that Lake Agassiz drained completely into Hudson Bay, leaving the Red River Valley. It's hard to beleive that only 8,200 years ago where I am siting (Fargo) was the bottom of an huge lake.