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Re: Late Cretaceous Arctic Climates
Y'all know that the configuration of the continents has historically
impacted both the presence and amount of ice at teh poles, and worldwide
Among other things.
----- Original Message -----
From: "Colin McHenry" <email@example.com>
Sent: Tuesday, July 28, 2009 8:43 AM
Subject: 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
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
t: +61 2 4921 8879
m: 0412 659541