A sudden chill

[EternalOptimist]

Archimedes just didn't like silversmiths, he liked to get them topped so he made it all up.

Anyway is the entire Wilkinson shelf floating, that would make a difference. If it is not all floating then surely melting would actually decrease sea levels due to density changes (assuming the ice and the ocean were a continuous body).

If the body is floating then it makes not a jot of difference, if it is not floating then it is required that the non floating part must be > 10% more than any submerged part due to the the relative densitys - i.e. water takes up about 10% less volume than ice thus if it melts it can either melt in place if it is not floating or take up the same volume if it is floating.

In any event polar ice only makes up about 2% of water on the planet. 97% is in the oceans.

I sure as hell can't get my head round this ice melting = sea levels rise like hell.

you have to take into account thermal expansion.

[Doggy Styles]

What about Increased Global Shaking, like in Italy the other day, and the Java tsunami? Has anyone linked that to human activity yet?

I think all that jumping at the Olympics might have an effect.

[ASB]

you have to take into account thermal expansion.

Well OK, but.....

Firstly it is reasonable to me to assume that if a bunch of scientists - irrespective of their agenda - say that if a small portion of the ice caps melts this will have a huge impact on shore based sea levels then they are probably right.

However, archimedes would imply that the floaing body melting would cause a sea level change by the amont of the change in volume of the state change between ice and water. In the case of ice melting this is an overall reduction in volume surely (ice being less dense than water). The impact of this - with no outside infuences would in fact be a reduction in sea levels surely? However, this would be counteracted by the floating body only being partly submerged - and would end up neutral.

So, thermal expansion, how much does water expand when heated until such point as it undergoes it's state change to gas? Surely none (or very very little).

So, to increase sea level the overall volume has to be increased - surely this can only happen if non floating ice melts and find's it's way into the oceans - i.e. it is unable to melt in place. It may well be the case that this is what happens with these large bodies of nominally static non floating ice shelf.

Estimates suggest that all the icecap ice is a total of just over 2% of the volume of the oceans. 1% [i.e. a 0.02% voumetric increase in ocean size] of this causing a 65 cm increase in sea level seems odd. Though I accept that what we have to consider to work this out is the overall volume against surface area. I have no idea of this calculation.

It may well be that tidal flows, lunar gravity etc all contribute to this effect. So in summary I accept I must be wrong, but I want to understand why.

It's probably just becoz I is fick.

[Doggy Styles]

What about Antartica? A million square miles over land, a mile thick, and if that all melts it is new water to the oceans. Isn't it?

Anyway, Peterborough will get it before me so it's not all bad.

[EternalOptimist]

Well OK, but.....

It may well be that tidal flows, lunar gravity etc all contribute to this effect. So in summary I accept I must be wrong, but I want to understand why.

It's probably just becoz I is fick.

You are not thick. The point about rising sea levels, is that the amounts that we are talking about, fractions of a milimeter per year, are so small that they can be masked. The subject is extremely complex which is why the sceptics <cough> have a good old laugh when the easily-led trot out the latest scare story. From memory, the main masking factors include thermal expansion, el ninos and other major weather systems, the earths 'wobble', the point on the land where you take the measurement (often goes up or down at 10 times the rate of the sea level).
Half of these are material, half of them are simply problems taking the measurement.
One thing I do know. If the doom mongers predictions of ten years ago had been right, I would have had to come into work this morning in a submarine.
There is no doubt that sea levels are rising, just how much and what is the cause ?