From: Mike Lorrey (mlorrey@datamann.com)
Date: Sun Apr 14 2002 - 10:15:36 MDT
Harvey Newstrom wrote:
>
> On Saturday, April 13, 2002, at 12:06 pm, Mike Lorrey wrote:
>
> > If at all. Let me say once again: Antarctica's ice caps will not
> > collapse. The ice sheets which are breaking away from the continent now
> > were already floating in the water. There is a difference between ice
> > SHEETS and ice CAPS. Greenland's ice cap may collapse, resulting in a
> > 3-9 meter rise in ocean levels, but this will require a rise in global
> > temperatures exceeding 6-9 degrees celsius.
>
> You may be right. But the big sheet that just collapse was famous. It
> was on all the maps. it helped shape the continent as seen from space.
> We now have to change all our maps. The outline that has remained
> unchanged for tens if not hundreds of thousands of years suddenly is
> gone in a single collapse. Maybe this won't be doomsday, but it is
> probably the biggest geological event that humans have been around to
> see.
Uh, once again, no. The coastal ice sheets have been steadily breaking
away because they have grown too big to resist the circum-polar ocean
currents. The ice they formed from is that generated in the last 1000
years by the Little Ice age, which is currently ending. The coastal ice
sheets have broken away many times in the past.
For example, when my cousin Andrew did his expedition to one of the
Katabatic canyons in Antarctica, at the base of the canyon he found the
dessicated remains of penguins, a location more than 250 miles from the
current edge of the ice shelf. They could only have gotten there if the
ice along that coast had been freed from that coast at some time in the
past, recent enough that wind had not eroded their bodies, but long
enough ago that there was once open ocean within a dozen or so miles of
his location.
Current thinking is that these penguin remains date to the pre-Little
Ice Age period, though there has not been any carbon dating done on them
(the scientific establishment at McMurdoe wouldn't let him take
samples).
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