It's getting windier. - Page 4

Raistlin · 08-01-2005, 02:14

LoL @ Richard and Bifta - Class

Shaun · 08-01-2005, 02:19

What Ras says is true its because when water freezes the molecules of water form an open structure rather than the tight structure of liquid water. The theory works fine for ice in the sea, BUT, what about the glaciers that are on land?

So taking that all into account the water levels WILL rise as the atmosphere warms up.

As for the comments about Global warming being a completely natural and reversible process, may I humbly suggest you check out what happened on Venus

Edit - Knew I'd covered this ground before!

http://www.cableforum.co.uk/board/sh...8&postcount=51

Raistlin · 08-01-2005, 02:19

And (before anybody says it) - yes I probably am a head-case

Raistlin · 08-01-2005, 02:23

Quote:

Originally Posted by dellwear

What Ras says is true its because when water freezes the molecules of water form an open structure rather than the tight structure of liquid water. The theory works fine for ice in the sea, BUT, what about the glaciers that are on land?

So taking that all into account the water levels WILL rise as the atmosphere warms up.<Snip>

But, the quantity of water that is contained within the land-based glaciers is fairly minimal compared to the quantity that is contained within submerged ice elsewhere. The savings in volume (God, I sound like a Government official) which are gained by the melting of this submerged ice should (in theory at least) create a reduction in overall sea-level which is sufficient to accomodate the water generated from the melting of land-based glaciers.

Actually, it might be kind of interesting if somebody would actually do the measurements of the different glaciers and do the maths on this one to see what the net increase / decrease in sea-level will actually be. I'm prepared to bet that it will be almost nothing!

ian@huth · 08-01-2005, 02:32

Water is a unique substance that is at its minimum volume at 4 degrees celsius and which expandswhen it is either heated or cooled from that temperature. The point is though that you are missing a couple of points in your theories:

1. There are over a dozen different types of ice, each with its own set of properties including different densities when all are at the same temperature.

2. Global warming increases the temperature of the sea which does expand with the increase in temperature.

So, it is possible that the melting of the icecaps alone may result in a drop in sea leavels but the increase in temperature of the sea (which is many times the volume of the water held in icecaps) will increase the seas volume and hence increase sea levels.

Richard M · 08-01-2005, 02:35

My head hurts.

Shaun · 08-01-2005, 02:47

Quote:

Originally Posted by ianathuth

Water is a unique substance that is at its minimum volume at 4 degrees celsius and which expandswhen it is either heated or cooled from that temperature. The point is though that you are missing a couple of points in your theories:

1. There are over a dozen different types of ice, each with its own set of properties including different densities when all are at the same temperature.

2. Global warming increases the temperature of the sea which does expand with the increase in temperature.

So, it is possible that the melting of the icecaps alone may result in a drop in sea leavels but the increase in temperature of the sea (which is many times the volume of the water held in icecaps) will increase the seas volume and hence increase sea levels.

On top of that you also have to take into account the effect of reduced reflection of the suns rays.

ZrByte · 08-01-2005, 02:47

A good example of water expanding when frozen into ice would be when making ice pops and the like. If you make it in a bottle you never fill the bottle right up or the ice while split the bottle open due to the increase in volume. Though ianathuth is correct, this doesnt take into account other types of water and ice.

ZrByte · 08-01-2005, 02:48

Quote:

Originally Posted by dellwear

On top of that you also have to take into account the effect of reduced reflection of the suns rays.

Regardless of the outcome it does proove his initial point that its not as clear cut as it is made out to be.

ian@huth · 08-01-2005, 02:51

If you want to know all there is to know about water have a read of http://www.lsbu.ac.uk/water/index.html

Your head will hurt Richard if you try to understand all that.

One very unusual aspect of water is that hot water freezes quicker than cold water even though hot water has to become cold water before it freezes. Work that one out.

Raistlin · 08-01-2005, 02:54

Quote:

Originally Posted by ianathuth

Water is a unique substance that is at its minimum volume at 4 degrees celsius and which expandswhen it is either heated or cooled from that temperature. The point is though that you are missing a couple of points in your theories:

1. There are over a dozen different types of ice, each with its own set of properties including different densities when all are at the same temperature.

2. Global warming increases the temperature of the sea which does expand with the increase in temperature.

So, it is possible that the melting of the icecaps alone may result in a drop in sea leavels but the increase in temperature of the sea (which is many times the volume of the water held in icecaps) will increase the seas volume and hence increase sea levels.

Agreed.....but.....

When water is frozen its volume increses by approximately 9%.

An increase in temperature of 16 degrees Celsius (from 4 degrees to 20 degrees) will decrease the density of the water by only 1%, an increase in temperature of 20 degrees Celsius (from 20 degrees to 40 degrees) will decrease the density of the water by only 6%.

Since Volume = Mass / Density (and the mass of the water will remain constant) the Volume should change by the same percentages for a given temperature increase.

This should mean that the increase in volume caused by the raised temperature will be accomodated by the decrease caused by the melted ice.

My science never was that good though so I'm happy to be corrected

Raistlin · 08-01-2005, 02:57

Quote:

Originally Posted by ianathuth

If you want to know all there is to know about water have a read of http://www.lsbu.ac.uk/water/index.html

Your head will hurt Richard if you try to understand all that.

One very unusual aspect of water is that hot water freezes quicker than cold water even though hot water has to become cold water before it freezes. Work that one out.

Ouch! Now MY head hurts! Nice link

ian@huth · 08-01-2005, 03:01

Quote:

Originally Posted by Raistlin

Since Volume = Mass x Density (and the mass of the water will remain constant) the Volume should increase by the same percentages for a given temperature increase.

Volume equals mass divided by density

Edit. See you realised your error

Raistlin · 08-01-2005, 03:02

Quote:

Originally Posted by ianathuth

Volume equals mass divided by density

Yep, typo. Just spotted that (and corrected it) myself

Thanks though

ian@huth · 08-01-2005, 03:06

Only 2% of Earths water is ice http://www.activebirthcentre.com/pb/...nourlive.shtml