How much will the oceans rise if all the sea ice melts?

Hello quik,

one possibly cannot tell, as the sea level would not rise evenly. Certain
parts of the world would probably have an increase of several feet while
others have none to very little.

Really? So why then when you pour yourself a glass of your favorite beverage and add several cubes of ice does the glass not overflow as the ice melts?

Oh, it was that kind of tricky question.

Fill your glass with water, and I mean fill it. Add an ice cube. Your glass overflows.

True, but the oceans are already "full" aren't they? So the ice is already sitting in a "full" glass.

Two physics items you'll want to review:

http://en.wikipedia.org/wiki/Fluid_mechanics

http://en.wikipedia.org/wiki/Displacement_(fluid)

14. How much does sea level rise if all the world's ice melts?
To a first approximation, if all the floating sea ice in the world melted, there would be no change in sea level at all, as the floating ice will have displaced its own weight of water. However, if land ice melts, that will raise sea level. All the world's glaciers and small ice caps contain approximately 0.5 m of sea level equivalent between them, while the great Greenland and Antarctic ice sheets contain approximately 7 and 61 m respectively. Consequently, if all the wolrd's ice melted in a very much warmer world, sea level would be approximately 70 m higher.

However, when land ice melts the distribution of the mass of water around the global ocean is by no means uniform. A large melting would result in a modification in the Earth's gravity field which would result in the sea level change being higher in some places than in others. [return to top]

Trick questions deserve trick answers.

Sorry Roger, not meant to be a trick question - just something to make you sit back and ponder

Good stuff, Archimedes was such a clever guy.

Ice on land = bad, not talking about that. Just ice on/in water.

An interesting proposition since it would require that ice not form at either of the poles during the dead of winter for all the ice to be melted. Of course if we warm up the earth, it means that the ice on land will move more quickly to the ocean thus forming more ice bergs. I guess that means the ONLY way to melt all the ice on the ocean is to also melt all the ice on land.

But of course you have to calculate the required temperature increase in the ocean to melt all the ice and then compute the expansion of water compared to it's present temperature. This means that even if you ignore the land ice you will still have an increase in oceans volume because of the expansion from heat.

Let us know when you do the calculations.

Will do, I'm hoping to figure it out while house prices are low and get a steal on some future beach front property!

Don't forget to account for continental drift. I'd hate for you to buy something and find out it's going to be a mountain someday.

Oh, good point!

Just a slight addition: It doesn't have to be land ice to raise sea levels. If a piece of ice is in a glass, and 10% of the ice is simply above the water, when the ice melts the water level will rise some from the part of the ice that was above the water.

Water is a very interesting molecule because it is most dense in its liquid form. This is due to the angle of the bonds (120 degrees I believe) between the hydogen molecule and two oxygen molecules. In a excited gas state (water vapor/steam) particles move around and are very far apart. In a liquid state, the molecules stay close but do not form a geometric structure. This allows them to get even closer. In a solid state (ice) what you have is a particles that are close, but formed in a very rigid structure. The geometry of the water molecule creates absences in the structure. Sometimes those absences end up trapping other gasses in them, other times they are a vacuum. This is why ice (a solid) floats in a liquid which is chemically identical.

The force of buoyancy is based on the difference between the density of two substances (typically fluids). If a portion of the ice is above water level, it does not contribute to the force of buoyancy, only to the weight of the ice.

E.G. - A system that includes: A cup, ice, air and water. The ice is not moving up or down so the system is at equilibrium. The air "presses" on the water, while the water "presses" on the air. The water level rises, which means that the water pressed back harder. The ice finishes melting and the water level stops. A new equilibrium.

T
K
O

They would rise high enough to need a large ark filled with two of every kind of animal...and enough supplies to last for 40 days and 40 nights of course.

This time, no Noah...just Al Gore.

The Authority on these questions is the IPCC-an arm of the UN. In their 2007 report they found the following:


Sea level rose at an average rate of about 1.8 mm/year during the years 1961-2003. The rise in sea level during 1993-2003 was at an average rate of 3.1 mm/year. It is not clear whether this is a long-term trend or just variability.
Antarctic sea ice shows no significant overall trend, consistent with a lack of warming in that region.

The next report from the IPCC is scheduled to come in 2012. However, it is important to note( see Wikipedia-Ipcc report 2007) that the PREDICTION of Sea Level Rises has been going down with each IPCC report. The latest report( 2007) predicts that sea level will rise by about a foot between now and 2090. This should be contrasted with predictions made in 1970-80 that sea level would rise 20 feet by 2090.

It would appear that the premier investigative body in the world on climate is LOWERING its predictions with regard to sea level rise by 2090.

See Wikipedia--IPCC R eport for 2007

Zilch

Land ice: now that's a different matter.

Additionally, a significant increase in "fresh" water in the oceans would reduce salinity, effectively raising the temperature at which ice would form from sea water.