Ice - Ice - Baby...

[real4star]

If you drop an ice cube in a glass of water/cola/lemonade it will displace its mass, raising the water level.
When the ice melts, the level will not get any higher because its mass has already been displaced.

So

There's ice on land and in the sea/oceans. On land the weight of the ice pushes the land down.
In the sea it displaces its own mass (as demonstrated by your cold beverage)

If all the ice on the planet melts into the sea's and ocean's... the ice in the sea won't affect sea levels at all and the weight lifted from the land mass would allow said mass to rise higher above sea level.

So to my (limited) knowledge, a total melt down of all the ice on earth would have minimal affect on sea levels.

I know this is a flawed theory... can anyone explain why without giving me a headache

[Mr Will]

The land doesn't float.

HTH

[real4star]

It does... sort of. The crust on the mantle
So if the land mass was to get lighter the mantle wouldn't have to excerpt so much force to hold it up (every action has an equal and opposite reaction etc etc)

Edited by real4star on Thursday 13th June 18:00

[Mr Will]

The mantle and crust are below the sea though. Whether they are technically floating is irrelevant.

[real4star]

The crust is broken up into tectonic plates, some are covered by more dry land than sea and some are more sea covered than land.

If the mass/weight of water/ice is moved from land to sea the extra mass in the sea will push the tectonic plate it covers down into the mantle.

The mantle/magma displaced by this will be displaced under another tectonic plate, pushing it (and the land on it) up.

Edited by real4star on Thursday 13th June 18:25

[Halmyre]

real4star said:

I know this is a flawed theory... can anyone explain why without giving me a headache

You'll have more than an effing headache to worry about if I ever lay hands on you! Putting a Vanilla Ice earworm in my head...

[Simpo Two]

real4star said:

and the weight lifted from the land mass would allow said mass to rise higher above sea level.

I think that's where your theory goes wrong. Bedrock doesn't go 'boing'.

So yes, the floating ice will melt but have no effect on sea level (though I suppose the sea will get colder and any polar bears standing on it will drown). Ice on the land will melt and raise the sea level. And ice is freshwater so the sea will become slightly less saline.

So... a bit higher and a bit colder and a bit less salty is my pronouncement

[Hackney]

Sea's and ocean's what?

[Halmyre]

Simpo Two said:

real4star said:

and the weight lifted from the land mass would allow said mass to rise higher above sea level.

I think that's where your theory goes wrong. Bedrock doesn't go 'boing'.

It does, but only very slowly. Sort of like Boiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiing. The British Isles are still slowly recovering after being forced down during the last ice age.

http://en.wikipedia.org/wiki/Post-glacial_rebound

[2 sMoKiN bArReLs]

If water wasn't H2O we'd all be dead because it would freeze from the bottom up, instead of the top down. (The O or H molecules don't like to sit next to each other, so as the temperature drops they organise themselves more. That's what ice is less dense & floats)

That's what a dipole is, and not a lady called Diana from Warsaw

[anonymous-user]

2 sMoKiN bArReLs said:

If water wasn't H2O we'd all be dead because it would freeze from the bottom up, instead of the top down. (The O or H molecules don't like to sit next to each other, so as the temperature drops they organise themselves more. That's what ice is less dense & floats)

i thought it was convection that caused the water to freeze top down, due to changes in density.

[2 sMoKiN bArReLs]

The Spruce goose said:

2 sMoKiN bArReLs said:

If water wasn't H2O we'd all be dead because it would freeze from the bottom up, instead of the top down. (The O or H molecules don't like to sit next to each other, so as the temperature drops they organise themselves more. That's what ice is less dense & floats)

i thought it was convection that caused the water to freeze top down, due to changes in density.

Kind of, it gets less dense though for the reason described..ice is more organised than water

[Simpo Two]

2 sMoKiN bArReLs said:

If water wasn't H2O we'd all be dead because it would freeze from the bottom up, instead of the top down. (The O or H molecules don't like to sit next to each other, so as the temperature drops they organise themselves more. That's what ice is less dense & floats)

In addition, water molecules arrange themsleves in loose clumps, IIRC about 8, which is why water doesn't behave like a small molecule (if it behaved as its mass suggests it would be a gas at normal temps).

[Skyrat]

2 sMoKiN bArReLs said:

If water wasn't H2O we'd all be dead because it would freeze from the bottom up, instead of the top down. (The O or H molecules don't like to sit next to each other, so as the temperature drops they organise themselves more. That's what ice is less dense & floats)

That's what a dipole is, and not a lady called Diana from Warsaw

There are so many things wrong with that I really don't know where to start.

The O and H atoms very much like to sit next to each other, and they form hydrogen bonds. The hydrogen bonds between water molecules is what helps to give ice its crystalline structure and make it less dense than water, because, to put it simply, the molecules in liquid water are actually more tightly packed than in ice, which is a more open structure.

It's the hydrogen bonding in water that gives it its unusual properties for a molecule of its size, i.e. high boiling point.

Anyway, getting back to the original topic:

real4star said:

If you drop an ice cube in a glass of water/cola/lemonade it will displace its mass, raising the water level.
When the ice melts, the level will not get any higher because its mass has already been displaced.

So

There's ice on land and in the sea/oceans. On land the weight of the ice pushes the land down.
In the sea it displaces its own mass (as demonstrated by your cold beverage)

If all the ice on the planet melts into the sea's and ocean's... the ice in the sea won't affect sea levels at all and the weight lifted from the land mass would allow said mass to rise higher above sea level.

So to my (limited) knowledge, a total melt down of all the ice on earth would have minimal affect on sea levels.

I know this is a flawed theory... can anyone explain why without giving me a headache

Your limited knowledge is very much flawed because what you said is not true.

Ice in a glass of water will displace its own weight/volume and so will not increase the water level as it melts. However, your analogies are wrong in both other examples.

Water on land is not floating, or displacing its weight. If you want an analogy, fill a glass of water to the brim, then drop in an ice cube. The water will overflow.

The ice floating in the arctic is fresh water floating in sea water. You are not taking the difference in density into account. Even the ice currently floating in the sea will increase the water level ETA: when it melts.

"The common misconception that floating ice won’t increase sea level when it melts occurs because the difference in density between fresh water and salt water is not taken into consideration. Archimedes’ Principle states that an object immersed in a fluid is buoyed up by a force equal to the weight of the fluid it displaces. However, Noerdlinger notes that because freshwater is not as dense as saltwater, freshwater actually has greater volume than an equivalent weight of saltwater. Thus, when freshwater ice melts in the ocean, it contributes a greater volume of melt water than it originally displaced."

source:
http://nsidc.org/news/press/20050801_floatingice.h...

Edited by Skyrat on Monday 1st July 16:18

[real4star]

[bsdnazz]

While ice on land does push the land down it must be remembered that land (rock) is denser than water. The specific gravity of something is a measure of how much denser than water the thing is.

As an approximation, rock is 2.5 times denser than water so 1m of ice will push the land down by 1/2.5 = 0.4m. If the ice melted the sea would rise by 1m but the land would only rise by 0.4 leaving a net rise of 0.6m in sea level.

All this ignores the fact that the land will sink and rise much more slowly than the ice forms and melts.