Re: Late Cretaceous Arctic Climates

[Colin McHenry <cmchenry@westserv.net.au>]

David Marjanovic wrote:
> Hang on a second. How much ice is necessary to account for the 
> sea-level changes? Does that amount really necessitate inland ice, or 
> are mountain glaciers (like those in southern Alaska which reach the 
> sea through a temperate rainforest) enough to explain the sea-level 
> changes and the Australian glacier sediments?
>
> The sea level is supposed to have changed by 25 m, right? 22 m is the 
> difference between today and 400,000 years ago when Greenland and West 
> Antarctica were ice-free. Is there a way to distribute that much ice 
> over the high-altitude and high-latitude mountains of the Early 
> Cretaceous world?


David - maximum sea level depth for the GAB in the late EK is 100-150 
metres (as far as we can tell). Regressions seem to have been total, 
i.e. sea levels fluctuated by at least 100-150m during the 4 (or maybe 
6) transgresive cycles during the Australian EK. So, yes, that would be 
a lot of ice melt.

I don't have an explanation for this... Would the extra land mass near 
the south pole (i.e. a large part of Gondwana) possibly have allowed for 
proportionally extra ice formation compared to Recent Antarctica?




--
Colin McHenry Ph.D.
Computational Biomechanics Research Group http://www.compbiomech.com/
School of Engineering (Mech Eng)
University of Newcastle
NSW 2308

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