Please read this question about the Archimedes Principle and global warming?

Question

According to the Arcimedes Principle, the volume of an object= the amount of water it displaces. The topic for World Environment Day 2007 is : Melting Ice A Hot Topic. The UNEP website talks about the melting ice caps and how they are flooding small islands. If the Archimedes Principle is correct, should melting ice lead directly to the flooding of small islands?

P.S. If I got anything wrong, please don't hesitate to tell me. I am only a kid whose mother told her about this Principle.

Er... I don't understand what you mean. If you drop five ice cubes into a cup of water, when they melt, they will lessen the amount of water displaced, but produce more water. So, according to the Archimedes Principle, shouldn't the volume of water stay the same?

Answer 1

The Archimedes Principle states that an object immersed in water will displace it's own mass*. For example, if you fill a bath tub to the brim and you get into the bath the mass (weight) of the water that is displaced (overflows) is exactly the same as your mass (weight).

This same principle holds true of icebergs, ice sheets, ice caps and anything else that's floating in the seas and oceans.
Provided they are floating they will already be displacing their own mass of water. If they melt they therefore have no effect on the sea level.

BUT, and it's a big but, only the Arctic is floating, this could melt completely and there would be no change in sea levels. The Arntarctic and Greenland ice sheets are not floating so they're not displacing any water. Any melting that occurs here runs off like streams and rivers into the seas and oceans causing the levels to rise.

Currently the melting of Antarctic and Greenland ice is one of the two factors which is causing sea levels to rise by an average of 3mm a year around the world. The other factor is that as the seas and oceans warm up they, like anything that warms, are expanding.

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* It's a bit more complicated than this because it applies to all liquids, not just water, and to gases as well. Note that it's not the volume of an object in water that's important but the mass of the object. A one ton styrofoam block and a one ton concrete block have very different volumes but when placed in / on water they will displace the same amount of water. Gas is a different matter, they will displace their own volume of gas irrespective of mass.

Answer 2

I think you've got the Archimedes principle down, now. The melting of sea ice is related to the amount of energy in the sea water. This energy for the most part is completely separate from the energy in the atmosphere. That's why you can have bitter cold air but still not have a lake freeze over while you can have extremely cold oceans on a burning hot day at the beach.

In other words, you can't just say that the same process that melts Arctic ice is melting ice on Greenland (Same goes for the mix of ice at our southern pole.)

When folks tell us to start worrying about the melting of land ice then they are not taking into full account the amount of energy in the atmosphere. If the temperature of the air is that much warmer, it vastly increases the amount of water vapor that can be held in the air - billions and billions of tons. Maybe not enough to account for all of the melted ice, but enough to be taken into consideration.

Answer 3

The fact of the matter is that no islands are being flooded due to melting ice caps.

Melting ice contributes to the water volume of the ocean in a positive way, but other effects off-set it. With a warming planet you have more water vapor in the air that will condense and snow on the interiors of earth's ice fields. Even though the edges of our ice fields are melting, as they always do, the interiors are building. Sea level rise is measured in millimeters per century. A few millimeters isn't flooding any islands.

Answer 4

that principle has nothing to do with islands flooding. all that principle means is if you have a bowl of water filled to the top and you drop an object in the bowl then the amount of water that comes out is equal to the amount of the volume of that object. ........when ice caps melt the water level will rise.......wich will then cause flooding and other effects. just like if you had a cup half full of water and you put five cubs of ice when they melt the water level will be more then half full.

Answer 5

You are correct. Specifically, here's how it applies in this case. Most of the ice isn't in the ocean, its on land (the Greenland and Antartic icecapes, mainly). As the ice melts, the water will run off into the oceans. Consequently, there'll be more water in the oceans and the sea level will rise, flooding small islands (and coastal areas if it gets bad enough). Just like pooring more water into a glass--the level of water in the glass rises. Only in this case the "glasses" are the ocean basins.

Answer 6

It's the *mass that is equal to the mass of water it displaces.
"A body immersed in a fluid experiences a buoyant force equal to the weight of the displaced fluid"
Ice has a lower density then water. When it floats a portion of it sticks up out of the water.
So when ice that already floats in the ocean melts it won't effect thesea levels.
When ice that is landbased melts the waterwill flow to the ocean and rise the sea levels.

Answer 7

Well, Im not a proffesional but it should according to the principal, since the melting ice has to go somewhere and will increase the level of the sea water. Im a kid too, but thats what I think.

Answer 8

Thats a good thought, but what if the ice that melts is on land then the oceans would rise. I think global warming is made up by elites so they have a reaon to controll everyone's life.

Answer 9

The icebergs are not the problem (and the arctic is one giant iceberg), but the ice-caps covering Groenland are. Same is true for the antarctic.

Answer 10

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