Younger Dryas Caused by Ice Dam Collapse?

  • Thread starter Thread starter baywax
  • Start date Start date
  • Tags Tags
    Collapse Ice
Click For Summary

Discussion Overview

The discussion revolves around the potential causes of the Younger Dryas, specifically examining the hypothesis that its rapid end was triggered by the collapse of an ice dam in the Bering Strait. Participants explore various mechanisms, including local changes in drainage from melting ice sheets and their implications for larger oceanic systems.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation

Main Points Raised

  • Some participants note that the newspaper article referenced discusses a different paper, which focuses on the end of the Younger Dryas due to an ice dam collapse in the Bering Strait.
  • One participant expresses skepticism about attributing major oceanic events solely to local mechanisms, suggesting that the timing of global oceanic responses may not align with localized events.
  • There is mention of isotopic behavior in the Greenland ice sheet during the Dansgaard-Oeschger events being similar to that of the Younger Dryas, raising questions about the frequency and causes of such events.
  • Some participants argue that the claim of solving the Younger Dryas cause through localized geological events is overly simplistic and potentially misleading.
  • A participant recalls a previous discussion regarding the influence of melting Columbia Ice fields on the Gulf Stream, indicating a belief that local effects may be insufficient to impact larger systems.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the causes of the Younger Dryas, with multiple competing views and ongoing debate about the adequacy of local mechanisms to explain global climatic changes.

Contextual Notes

Limitations include the dependence on specific geological interpretations and the unresolved nature of the timing and effects of ice dam collapses on broader oceanic systems.

baywax
Gold Member
Messages
2,175
Reaction score
1
This is a story that just came out today (Nov. 16, 2009):

Here's the story:

http://www.nationalpost.com/todays-paper/story.html?id=2228018

Here's the paper:

http://cat.inist.fr/?aModele=afficheN&cpsidt=20683217

Of course, its all Canada's fault again. :-p
 
Last edited by a moderator:
Earth sciences news on Phys.org
The newspaper story is about a different paper. The paper you linked to has another author, and it is about the rapid end of the younger dryas after the collapse of an icedam in the Bering straight and not in Saskatoon, Canadaa.
 
willem2 said:
The newspaper story is about a different paper. The paper you linked to has another author, and it is about the rapid end of the younger dryas after the collapse of an icedam in the Bering straight and not in Saskatoon, Canadaa.

Oops :redface:

All I've got for you is this quote from the "Ottawa Citizen"

"The findings, presented at the recent BOREAS climate conference in Finland, are highlighted in the latest issue of New Scientist."

No link as of yet.
 
It's always amazing to see how a major oceanic event is explained with local mechanims like changes in drainage of melting ice sheets. Also interesting that both the start and the end of the event are explained by a similar event

If you can stop and restart gulfstreams with that, could explain the features in the North Atlantic like the Cariaco basin, but it's pretty hard to maintain that with similar events in the Pacific, like http://geology.gsapubs.org/content/33/2/157.abstract. Due to the big lag in the world wide oceanic conveyor belt, it's a bit awkward to expect near simultanous reaction due to a local event in the North Atlantic.

Also mind that the isotopic behavior of the Greenland ice sheet during the Dansgaard Oeschger events (dD, d18O and d - deuterium excess) are practically identical with the Younger Dryas (http://www.sciencemag.org/cgi/content/full/309/5731/118?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=NorthGRIP+&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT). Would this suggest that all these events are caused by a ice dam breach, due to the melting of major ice sheets, every few thousand years?

I think that the claim of solving the cause of the Younger Dryas with that kind of geologic pinpricks is a bit too bold.
 
Andre said:
It's always amazing to see how a major oceanic event is explained with local mechanims like changes in drainage of melting ice sheets. Also interesting that both the start and the end of the event are explained by a similar event

If you can stop and restart gulfstreams with that, could explain the features in the North Atlantic like the Cariaco basin, but it's pretty hard to maintain that with similar events in the Pacific, like http://geology.gsapubs.org/content/33/2/157.abstract. Due to the big lag in the world wide oceanic conveyor belt, it's a bit awkward to expect near simultanous reaction due to a local event in the North Atlantic.

Also mind that the isotopic behavior of the Greenland ice sheet during the Dansgaard Oeschger events (dD, d18O and d - deuterium excess) are practically identical with the Younger Dryas (http://www.sciencemag.org/cgi/content/full/309/5731/118?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=NorthGRIP+&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT). Would this suggest that all these events are caused by a ice dam breach, due to the melting of major ice sheets, every few thousand years?

I think that the claim of solving the cause of the Younger Dryas with that kind of geologic pinpricks is a bit too bold.

That's why I asked Andre! I remember discussing this idea quite a while ago in this section... something about the Columbia Ice fields melting and effecting the the Gulf Stream off of what is now New York. Your assessment was similar in that it seemed to little an influence to effect such a large system. Ever onward! Thank you!
 

Similar threads

Replies
8
Views
9K
  • · Replies 4 ·
Replies
4
Views
5K
Replies
8
Views
5K
Replies
17
Views
7K
  • · Replies 68 ·
3
Replies
68
Views
23K
  • · Replies 33 ·
2
Replies
33
Views
21K
  • · Replies 101 ·
4
Replies
101
Views
32K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
5
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K