RE: Wobble Wobble

From: Rik van Riel (riel@nl.linux.org)
Date: Tue Feb 01 2000 - 09:10:58 MST


On Tue, 1 Feb 2000, Alejandro Dubrovsky wrote:

> > discounted it. The idea
> > is that were the Ross Ice Shelf in Antartica to be released
> > so that it went
> > floating off it would destabilize the earths rotation with
> > ugly results....
> > Kinda like a tire out of balance.
>
> Don't know if it's so far fetched. my personal knowledge in the matter is
> nill, but i read an article in new scientist (either 28/11/1998 or
> 5/12/1998, can't remember) about someone proposing that 600 million years
> ago the earths tilt was at around 51 degrees (they were using this to
> justify the fact that there used to be glaciers around the equator at that
> time), but since the earths tilt is "known" to have been around 23 degrees
> about 430 million years ago they needed to find a quick way of changing the
> earth's tilt by that amount in that short (170 million year) period. one of
> them suggested that ice formation around the current poles would have
> shifted the tilt by the needed amount. the contention from other geologists
> seemed to be the difficulty in the creation of the ice in the right places,
> not in the maths of the tilt shift which suggests that the calculations in
> that department were correct. i'll see if i can find it again.

An imbalance in the formation of ice is in fact quite
easy and very visible today.

In the east of north America there is ice and snow in
the winter and the weather is cold from about 40 degrees
north. The Atlantic water is cold polar water.

In Europe there's a warm gulf stream carrying north from
the equator. Weather in Europe is pretty decent till about
60 degrees north. Once you get further to the north (or to
the east, away from the Atlantic), you'll get to experience
`real' winter.

That's a difference of about 20 degrees, or 2500 km. If for
some reason (vulcanic activity in the atlantic that forms
new mountains and disrupts the flow of water) the difference
would become any bigger, we could start wobbling in a pretty
short time period.

In fact, some people believe that we had such a wobble at the
end of the last ice age, some 12500 years ago. This is still
a controversial thing but there's anecdotal and geological
evidence pointing to some pretty devastating events back then.
Then again, there's other geological evidence suggesting that
nothing of that magnitude happened and that the end of the ice
age wasn't that spectacular at all.

regards,

Rik

--
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of people. That is its real strength.



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