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Re: Late Cretaceous Arctic Climates

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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