# Water expansion

Foraker

## Main Question or Discussion Point

[SOLVED] Water expansion

Ok, I was just sitting at work, bored as usual. And i was wondering.. How big would the oceans get if they completly froze up. So to find out this answer i wanted to find out how much water expands when it freezes, but i cant find it in my web searching. Could any of you help?

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I'm not positive, but I know the answer is ALOT... Exponentially... Especially when you're talking about all the oceans all over the planet! I doubht there is any equation that can help you here.

Foraker
what? how can i not figure it out. If water expands like 33%(im just making this up) then i take the volume of the ocean and figuire out how much bigger it would be. I dont see a problem, i just want to know how much 1 liter of water would expand.

Integral
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Gold Member
I believe ice expands about 4%. You should be able to get some data simply by observing an ice cube in a glass of water. That little bit that is above the surface of the water is your expansion amount.

LURCH
Originally posted by arcnets
I got lots of hits on 'density of ice'. See e.g. here:

http://hypertextbook.com/facts/2000/AlexDallas.shtml

Don't forget to take into account that ocean water also contains lots of salt and other stuff...
Right, but the ice won't (for the most part). I think Integral has the right idea; the amount of an ice-cube that sticks out of the water is the amount by which the ice expanded when it froze. I seem to recall hearing on numerous occassions that the part of an iceburg we see above water is only 10% of the total burg. This agrees pretty closely with the info at the link arcnets provided.

Foraker
Umm, i might be able to use the density of ice, but i dont think i did it right. But the volume of the oceans now i 362x10^6, the reason i think my answer is wrong is because the volume of ice i got would be 111000x10^6(rounded :P) which is something like 300 times the size of the ocean. Which seems a little too big. But if i use Integrals 4% idea(which sounds pretty good to me) then the ice cube ocean would be 25 times bigger.

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Either way it would cover all the landmasses and bring on the next ice age.

Originally posted by Foraker
Umm, i might be able to use the density of ice, but i dont think i did it right. But the volume of the oceans now i 362x10^6, the reason i think my answer is wrong is because the volume of ice i got would be 111000x10^6(rounded :P) which is something like 300 times the size of the ocean. Which seems a little too big. But if i use Integrals 4% idea(which sounds pretty good to me) then the ice cube ocean would be 25 times bigger.
Uhh... if something expands by 4%, doesn't it mean that the final size would be 104 per cent of the original, which means that the frozen oceans would be 1.04 times bigger?

Originally posted by arcnets
I got lots of hits on 'density of ice'. See e.g. here:

http://hypertextbook.com/facts/2000/AlexDallas.shtml

Don't forget to take into account that ocean water also contains lots of salt and other stuff...
From that site
"The density of ice Ih is 0.931 gm/cubic cm. This compares with a density of 1.00 gm/cubic cm. for water.
Wouldn't this indicate a difference of ~7%?

Yes, but all the other sources on that site give .917 g/cm3, which means ~9% expansion. Relative to standard conditions, that is. Which you don't have in the ocean.

I guess Integral remembered the number 4 in this context because water reaches its maximum density at ~4°C.

Integral
Staff Emeritus
Gold Member
Originally posted by arcnets
Yes, but all the other sources on that site give .917 g/cm3, which means ~9% expansion. Relative to standard conditions, that is. Which you don't have in the ocean.

I guess Integral remembered the number 4 in this context because water reaches its maximum density at ~4°C.
That may well be. I find the range of densities that are showing up a bit surprising. How about if you report the conditions corresponding to that density.

Janus
Staff Emeritus
Gold Member
Well first off, You have to decide whether all the ice will be Ice I. If it is, then its density is about .92g/cm³ .

Secondly, you need to know the average density of sea water. One site I found lists it as around 1.028g/cm³

This gives about a 11.74% expansion upon freezing.

If you want to know how much higher this would raise "sea level" you also have to take the following into account.

As the water freezes, the salt will precipitate out. There is about 16cm³ of salt per liter of seawater, This will add to the total volume filling the ocean basin and raise the ice level some.

The ice level should be about 13.33% above what it is. The average Ocean depth is about 4000 meters, which gives us a ice level a little more than 500 meters above present sea level.

That's assuming all the above values and assumptions are reasonably correct.

Don't forget to take into account that ocean water also contains lots of salt and other stuff... [/B]
Like fish...

Had heard a figure, long time back, (accuracy??) had stated that if you were to take all of the salt out of the Oceans, pile it up on the land, it would cover the land masses, terrestrially, five hundred feet deep!

(But this could be wrong, It's been along time...)

You also must not forget that the area of the cross section of land isn't regular, so, it is not like if it is in a cylinder or sth.
I think any fast calculation without a deep study will give a quite wrong answer.