Rapid cooling 12,700 years ago in Western Europe caused by wind shifts

[Mammo]

There's another area of contention which is more clear-cut. In thread 'Happy Perihelion' you were debating with Xnn about the ice sheets of North America and the northern hemisphere Happy Perihelion, post #26

Further evidence of extensive North American glaciation is given in Imbrie and Imbrie's book 'Ice Ages : Solving the Mystery'. Glacial till deposits are an excellent indicator of the extent of the ice sheets.

 

[Andre]

Further evidence of extensive North American glaciation is given in Imbrie and Imbrie's book 'Ice Ages : Solving the Mystery'. Glacial till deposits are an excellent indicator of the extent of the ice sheets.

And what do you see in reality, reading actually what it says? Confusion and conflict and Imbrie & Imbrie had not even begin to think about possible dating calibration problems with 14C dating, which lead to huge differences in the 20 ka bracked.

 

[Mammo]

And what do you see in reality, reading actually what it says? Confusion and conflict and Imbrie & Imbrie had not even begin to think about possible dating calibration problems with 14C dating, which lead to huge differences in the 20 ka bracked.

No, the confusion was the realisation that there are warm interstadials during a glacial period. This was evidenced by the advance and retreat of the ice sheets.

I think that you have a valid case in showing that the Eurasian icesheet is now believed to be a lot less extensive than initially assumed. But this has a reasonable explanation - a low rate of precipitation. What is the reason why there wouldn't have been extensive glaciation of the North American continent?

 

[Andre]

No, the confusion was the realisation that there are warm interstadials during a glacial period. This was evidenced by the advance and retreat of the ice sheets.

I think that you have a valid case in showing that the Eurasian icesheet is now believed to be a lot less extensive than initially assumed. But this has a reasonable explanation - a low rate of precipitation. What is the reason why there wouldn't have been extensive glaciation of the North American continent?

We are running around in circles. As I have shown over and over again, the paleo zoological evidence in Siberia massively points to warm conditions just prior to the last glacial maximum, in the assumed period of the advancing ice sheets in America but as advancing ice sheet kill evidence where they flow, the only valid evidence is likely the dating of maximum extent but there is no way to know how long the sheet was at that maximum. Moreover it would be pretty interesting to see an explanation for a big ice sheet on America some 24,700 calendar years ago, when the http://www.yukonmuseums.ca/mammoth/abstrmol-mor.htm

 

[Mammo]

We are running around in circles. As I have shown over and over again, the paleo zoological evidence in Siberia massively points to warm conditions just prior to the last glacial maximum, in the assumed period of the advancing ice sheets in America but as advancing ice sheet kill evidence where they flow, the only valid evidence is likely the dating of maximum extent but there is no way to know how long the sheet was at that maximum. Moreover it would be pretty interesting to see an explanation for a big ice sheet on America some 24,700 calendar years ago, when the http://www.yukonmuseums.ca/mammoth/abstrmol-mor.htm

Professor Guthrie talks about the advance of the treeline during interstadials in his book. This is the real anomaly which needs understanding with a full explanation. The insolation due to orbital mechanics is symmetric and calculable. So why are there large periods of warm weather during a glacial period? This is the question.