It's getting windier. - Page 6

Theodoric · 08-01-2005, 13:17

Quote:

Originally Posted by Raistlin

Also spotted the fact that I had claimed that the density will increase as the water is heated

Still not sure about the maths though. Does it neccessarily follow that a decrease in density of (say) 6% will lead to an equal (6%) increase in volume? It seems to make sense but my head's a bit foggy

Oh, and sorry if it seems like the thread's been hijacked. It hasn't, well - not really anyway

A 6% decrease in density will lead to an approximate 6% increase in volume.

v = volume, w = weight, d = density

v = w/d

For a weight w:

Initial volume, v1= w/d

Final volume, v2 = w/(0.94.d)

v2/v1 = 1/0.94 = 1.0638 (to 4 dp), that is an increase in volume of approx 6.38%

Halcyon · 08-01-2005, 13:29

I kept getting woken up last night.
My bedroom is in the roof and I could hear the roof slates moving and the wind really was making my house move. I could feel it.
Seems to have died down now and the suns out...Yay

**Paul** · 08-01-2005, 13:46

How did a wind thread move onto ice

Anyway, I thought ice floated on water, and the water it displaces while floating is less than the total amount of water in the ice - therefore if it melts, the overall water level rises.

nffc · 08-01-2005, 13:50

Quote:

Originally Posted by Paul M

How did a wind thread move onto ice

Anyway, I thought ice floated on water, and the water it displaces while floating is less than the total amount of water in the ice - therefore if it melts, the overall water level rises.

It does, but 1 litre of ice will contain less water molecules than 1 litre of water.

The whole reason ice floats is because it's less dense than water.

Overall if all the ice was to melt I'm pretty sure that the water level will fall due to the volume decrease. As has been explained countless times.

[It's still pretty windy though]

08-01-2005, 13:53

The question is surely how much of the polar ice caps are on land. If the ice is actually on land above sea level, then, when melted, it will run down to sea level, thus raising the water level.

bopdude · 08-01-2005, 14:07

Well as per my earlier post, I like the storms etc etc, but not the after effects.....

we've just got back from town to find a whole in the roof with about 6 tiles adrift and a couple on the pavement, looks like another job to be done

nffc · 08-01-2005, 14:12

Quote:

Originally Posted by JohnHorb

The question is surely how much of the polar ice caps are on land. If the ice is actually on land above sea level, then, when melted, it will run down to sea level, thus raising the water level.

Yes. And how much of them will actually melt due to the temperature rises.

IF global warming is not, as I believe, a load of total ********.

bb31 · 08-01-2005, 15:12

survived the nite, but my fence hasnt

had to be let loose with hammer and nails to botch them up for now - dont know how long they will last if this wind keeps up

SMHarman · 08-01-2005, 15:24

Quote:

Originally Posted by Raistlin

Global warming won't cause an increase in sea-level, it's all hype from militant fluffy types trying to get us to eat Tofu!

<Pay attention - here comes the dodgy science bit >

When you put Ice in a glass of water what happens to the level of the water? It raises (of course it does). As the ice melts does the level of the water continue to raise? No, it actually falls.

The reason that Ice floats is that it is actually less dense than water (water becomes less dense as it cools, in a complete contradiction to the normal scheme of things) and therefore it actually displaces more water (due to the increased volume of the ice) than it contains - enabling it to float.

It therefore stands to reason that the volume of water being displaced by the polar ice caps (ie the amount by which the sea-level has already risen due to their formation) is greater than the volume of water contained within them. So, when they melt, the water contained within them will actually take up less volume than the ice does which means that the sea level should fall slightly.

Obviously there is a large amount of ice above the water but this is only a small amount of ice compared to what is below the surface (the tip of the iceberg if you will) and should therefore have an almost negligable effect. I would expect the net result of complete polar ice cap meltage to be that the sea-levels will remain pretty much as they are at the moment.

<Dons a flame-proof suit and waits patiently>

OK but the ice sitting on the swiss glaciers is not in the ocean, when that melts into the ocean that raises the level of the ocean, apart from that the science is foolproof.

Chimaera · 08-01-2005, 15:31

Quote:

Originally Posted by bb31

survived the nite, but my fence hasnt

had to be let loose with hammer and nails to botch them up for now - dont know how long they will last if this wind keeps up

I sympathise bb! I'm having a new fence put up on Wednesday (partly cos the old one is knackered and partly to hide next door's sat dish) so I hope the old one survives till then!

08-01-2005, 15:52

Quote:

Originally Posted by JohnHorb

The question is surely how much of the polar ice caps are on land. If the ice is actually on land above sea level, then, when melted, it will run down to sea level, thus raising the water level.

The largest glasier in the world is in Antartica, and is contained by the Ross Ice Shelf. The Ross Ice Shelf itself has show signs of loosing its integrity over the last decade or so. (Some of you may remember the peice or sea ice the size of Spain (I think), broke of several years ago.) The glacire behind the Ross Ice Shelf contains several Billion tonnes of water, and if released into the ocean by the continued breakup or the Ross Ice Shelf, could be the death knell of may coastal cities.

ian@huth · 08-01-2005, 16:21

Quote:

Originally Posted by Paul M

How did a wind thread move onto ice

Anyway, I thought ice floated on water, and the water it displaces while floating is less than the total amount of water in the ice - therefore if it melts, the overall water level rises.

I started the thread because the wind was howling outside my study window and I have the distinct impression that the past few years have seen the weather getting windier and windier. Watching TV over the past couple of weeks has shown us the enormous forces of Mother Nature with many places wiped out by the Tsunami. This led to a few searches on Google which came up with things like a large increase in sea level being likely due to global warming and other factors. Vast icebergs breaking away from Antarctica have been in the news for the past couple of years. Animal life is being affected. All in all the starting point for discussion on what can be a fascinating and thought provoking subject.

So the howling wind prompted the thread but, as expected, it quickly went onto other aspects of Mother Nature which could all be contributors to producing this wind.

AndrewJ · 08-01-2005, 16:40

Main contributer to the wind is all the hot air the goverment speaks.

paulyoung666 · 08-01-2005, 16:46

Quote:

Originally Posted by AndrewJames

Main contributer to the wind is all the hot air the goverment speaks.

maybe you should start a thread on that topic then

anyway , i have never ever seen as many roofs , fences etc damaged before

, the whole street is littered with broken slate tiles

Shaun · 08-01-2005, 17:35

Quote:

Originally Posted by BBKing

...has anyone pointed out that working out sea level rises due to changes in ice/water density is fairly irrelevant as one of the ice caps is largely on land?

Sorry to hear about the bad night BB.

I mentioned about the glaciers on Land, post 41 and you are right there will be a reduction in the albedo effect which could in theory result in a runaway greenhouse effect like has happened on Venus.

Obviously there is also data that points toward it being totally natural that the global mean temp fluctuates but personally I'm worried!