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A query - Ice caps and Ice Ages


Kettle

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Some nice person bought me a "Book of Useless Information" a while back and one of the entries caught my interest:

 

H2O expands as it freezes and contracts as it melts, displacing the exact same amount of fluid in either state. So if the northern ice cap did melt, it would cause absolutely no rise in the level of the ocean

 

Equipped with just a GCSE in Dual Science that was news to me (the bit about oceans - not the freezing and contracting) - is there anyone more learned in these matters that could corroborate this?

 

Also (question #2)

I remember back in the 1990s there seemed to be a group of scientists who said that a significant portion of the effects of global warming could be attributed to the fact that we are still at the tail end of the most recent Ice Age so obviously temperatures across the globe will increase until we fully emerge. They seem to have been a bit quiet of late (and everyone is once again talking about pollution) - has this theory been thrown out?

 

Cheers

:)

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It's true.

 

There would be a slight rise in sea levels, from the melting of antarctica (it's on land), however most of the change would be from the thermal expansion of water.

 

And we don't know about the rest of it.

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Originally posted by Sayonara³

Yes, ice expands rather than contracting, because the bonds are less space efficient in the solid form or something...

 

That's why ice floats in water - it's less dense.

 

Water's odd stuff, and it's quite likely that this property is the only reason life exists.

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Yup - I knew about the basic properties of ice (that it floats, is less dense etc) but it was the part about the oceans not, in fact, rising should the ice caps melt that took me by surprise (just never put 2 and 2 together I guess - either that or I'm a sucka for hollywood science :rolleyes: )

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Originally posted by Kettle

Yup - I knew about the basic properties of ice (that it floats, is less dense etc) but it was the part about the oceans not, in fact, rising should the ice caps melt that took me by surprise (just never put 2 and 2 together I guess - either that or I'm a sucka for hollywood science :rolleyes: )

 

As I said, thermal expansion of water

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Originally posted by Sayonara³

Ages ago when Focus magazine was new and less crappy, I sent that in to the questions page.

 

They printed it with a picture of an iceberg and everything \o/

 

w00t \o/ way to go, Sayonara :)

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If the Antartic cap melted levels would rise, because the vast majority of the ice there is on a land continent.

 

The ice at the Arctic pole is basically just floating about, so you might as well consider it to be part of the oceans.

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Aha :) Thanks

 

Btw - am I okay asking stuff like this? I mean, are n00bs with no grounding in science (but a huge fascination with it) welcome to post idiotic questions everywhere or are these forums for serious discussion between people with degrees in Cosmology etc?

 

Maybe it might be worth having a forum subsection in each group devoted to Q&As - where someone can ask a question and people can suggest answers - much like you get in the back of magazines :)

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Originally posted by Sayonara³

If the Antartic cap melted levels would rise, because the vast majority of the ice there is on a land continent.

 

The ice at the Arctic pole is basically just floating about, so you might as well consider it to be part of the oceans.

 

Oi, stop giving things I said in the 2nd post in the thread as new information

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  • 2 weeks later...

The idea that recent changes in temperature could be attributed to the ending of an ice age has mostly been dismissed. Temperatures should be going up, but they should not be going up as fast as they have been. This is largely down to more comprehensive and accurate temperature data, but also partly down to the fact that temperature is not the only measure of the state of the climate. Global temperature averages conceal local effects, which will depend on local eco- and weather systems. Heat energy which melts ice, for example, doesn't make the air warmer at the same time. Furthermore, from recent changes in the behaviour of phenomena like el nino, it is pretty clear something is up.

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Originally posted by rdjon

Odd then that scientists have been observing it by satellite and have spent 7 years drilling through 3km of ice there then. Big, thick glacier at 3km ;)

 

BBC News

 

 

Ok, I was wrong. There is an ice sheet. Quite right too. But I'm not convinced 50 billion tons of water would increase the global sea levels by 7m. Plus Greenland is actually a basin, so the increase would not be that much. However, you proved me wrong before.

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I seem to remember from dim amd distant undergrad days that we are in a "super-interglacial" period and that we are supposedly a few thousand years overdue for a new ice-age? I seem to remember something about ice-ages being separated by approx. 10,000 year interglacials...or am I wrong? Don't rush out and by your thermals just yet.

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