Scientists aren't making a "sea level rise" issue out of the north polar icecap changes. So in that sense, your question starts out right off as a strawman issue. Worse, you completely misunderstand the concept of displacement (and introduce yet another strawman issue) when you write that "water expands when its frozen." It's true, it does. But the sea level doesn't change when it melts for that reason, neither less nor more. It's about mass and displacement and the MASS of the ice, regardless of its volume differences, is what causes the displacement. It wouldn't matter if the ice expanded into twice its volume when freezing. Or 10 times. There would be no change due to melting ice, as the sea level accounts for the mass of the ice... it has no way of "looking" at the volume of the ice... only the mass.
So your question suggests to me that you need to learn a little more physics, yet. And you need to stop listening to non-scientists, too.
The antarctic ice is a more complex and different issue. Same with Greenland ice. I believe that Greenland contains enough ice sitting on land that if it all melted into the ocean (it is melting at more than 300 cubic kilometers of ice per year right now and that is increasing), it would raise ocean levels some 6-7 meters (memory serving.) I think antarctica is about another 70 meters worth of ocean rise. Those are the two big elephants in the room. Then there are glaciers, snow pack, and so on distributed around the world which are in decline but I don't think they represent anything more than a meter or so, put together. All told, I've read some 80 meters of total sea rise are indicated by actual observation of ancient sea levels when there was little ice stored on Earth (more than one such cycle.)
One thing you probably also haven't considered is that there is land rebound that takes place as the ice melts off into the oceans. With less mass on top, the land mass underneath floats up a little more. It's semi-significant, but I've not studied it so I really don't know for sure. I just know that it's being examined and there are attempts to take it into account, now.
Tomcat is right about ground moving up and down. The area around the great lakes and further north is still rebounding upwards from the melting glaciers which melted over 10 thousand years ago. Geologists call that isostatic rebound. The Great Lakes were carved very deep during successive glacial periods so I don't think there is much chance they dry but the land will rise and the relative level in the lakes may fall. It depends on the what happens. Similarly ground near the ocean isn't always stable. In New Orleans it is sinking and in Newport Beach it is rising. This causes relative changes in sea level with the shore. There is a difference between relative sea level rise and actual and actual SL rise isn't perfectly consistent everywhere due to numerous reasons such as the melting ice and differences in density etc. The main reason the oceans have risen in the last 50 years is thermal expansion, not melting of glaciers.
Deniers will tell you many things on this topic all of it untrue some state it not rising at all, some state it only a few millimeters a year some say "the rate is not increasing" see kano's answer.
As it stands sea level rise is down to two things thermal expansion of water, percentage wise it's a tiny effect but when the oceans of the world average ~4000m deep that tiny percentage can be noticeable the other addition is glacial ice melt.
At the moment it is about evenly matched between ice melt and thermal expansion adding to rise, the worry scientists are trying to explain to the ill informed (deniers) is that as we warm further ice will accelerate and become a much larger part of that melt and the year to year rate of sea level rise will increase. Kano's claim that this is not happening is nonsense (as are most of his claims)
Historical data shows the rise of the end of the last glacial period fizzled out ~4000 years ago and pretty much stopped 2000 years ago the current rise is a return to a rate of rise not seen in 7000 years.
http://en.wikipedia.org/wiki/File:Holoce...
The claim the rate is not rising is also nonsense 100 years of tide gauge data show a rate of rise of ~1.7mm per year for the last 20 years that rate is now over 3mm per year, i.e. pretty obviously it is increasing.
http://climate.nasa.gov/key_indicators#s...
Then we have another repeated denier claim "such massive amounts of ice melt very slowly (thousands of years)" this one is actually true, of course what the claim leaves out is that this is for a total melt of Antarctica and Greenland, any scientist will tell you this, but unlike deniers they will also tell you that for the type of sea level rise predicted by the end of this century (1-2m) only ~1-2% of these glacial masses need to melt and they are melting.
http://climate.nasa.gov/key_indicators#l...
As to talk of ice expanding, while this is true, the idea you put forward he (and one pushed by one of our chief deniers here, in the last few days) is utter nonsense, Glacial ice is mostly land based, Northern ice (as you refer to it) is sea ice, a very thin layer on the surface it's melting will have no real effect on sea level except that once it's gone the Sun will be able to warm these regions more, adding to the effect of thermal expansion.
"Antarctica will melt too which might make up for the volume lost, but since it's not completely ice like the north"
Ummm, sorry what, the Northern icecap is sea ice on average just 2m thick floating on the Arctic sea
The Antarctic ice sheet is ~2100m thick on average and about the same area as the continental U.S. Take a science class, please.
Global warming is the product manufactured by media collaboration world wide. Combine algamated networks manufacturing nostalgia and extreme fear, the universal product the television Industry fabricated after the millennium bug back fired in their faces. Before that it was D-day end of the world nostradamous theories that never eventuated where they waited for the worst imaginable syndrome to appear but as usual nothing at all happened.
Find one place where the oceans have risen? We have king tides that come and go, lots of storms that create havoc out at sea but they all recede even the worst tsunamis dump their load and all returns back to normal. There is no place on earth that scientist can show where the waters are rising. The tides are remaining steady and water levels are where they have been for centuries. Today man has more weather reading equipment that didn’t exist in the eighteen or seventeen hundreds so there is no scientific proof that the earth is getting warmer only the miserable fear that the world wide Media afflict and that’s mere Speculation. There’s nothing more dangerous than the media manufacturing fear, it’s what they do best and Global Warming is their utter weed. They master world wide fear and have every politician, citizen’s world wide scared to oblivion as it’s got every one scarred. That’s how dangerous the warped media really are. What should be of major concern to heal the world properly is tougher media legislation to keep those crazy bastards in line and it time the world leaders call for tighter media legislation as today they are too wild and times extremely dangerous. Brainwashing and the world is completely sucked in Blind and refuse to see the real tragedy.
Sea levels would mainly be affected by the melting of ice currently sitting above sea level on dry land, in Greenland and Antarctica.
Arctic ice will not cause sea level to rise because when it melts it will displace the area it already occupies. Melting land based glaciers will cause sea level to rise as will what is known as thermal expansion or matters tendency to expand as it warms. Fresh water begins expansion after a point of 4C
Glacial retention, thermal retention and tectonic uplift have more to do with sea level rise than melting glaciers. For example the great lakes will be dry one day because they are depressions left over from the weight of the glaciers from the last glaciation, and they are slowly being lifted back up by the earths crust and mantle, and subsequently the water will be pushed out and into the ocean. Similarly all over the ocean depths there are mountains being pushed up by tectonic forces which causes sea level to slowly rise.
Your not accounting for all the glaciers on this planet.They're all melting,that melt water goes down to the seas contributing to rising sea levels.
http://www.colorado.edu/news/releases/20...
http://www.worldviewofglobalwarming.org/...
Not going to get into whether it's global warming or not.Do know our planet goes through periodic warming and cooling spells.If all glaciers world wide including north and south poles melt,will look like this;
http://en.wikipedia.org/wiki/Western_Int...
Melting Arctic ice will not effect sea levels, Greenland and Antarctica could, but such massive amounts of ice melt very slowly (thousands of years) Glaciers are basically a pee in the ocean.
Sea levels are rising at 6.7 inches per hundred years with no sign of acceleration, so nothing to worry about, unless you live in Venice.
http://www.ihatethemedia.com/wp-content/...
By the melting of ice from peaks and because of glaciers.
To avoid pointless, off topic arguments, let me just say that I'm not claiming that global warming is real or fake, so please don't try to answer with that. Answer this like it's a hypothetical situation, whether you believe it or not.
I hear people saying that the polar icecaps melting will cause the sea level to rise and eventually lead to the disappearance of the north pole landmass since it's not actually land.
What I'm wondering is how all that ice melting will cause the sea to rise if that ice in the north is already displacing the ocean water. And to top that off, water expands when it's frozen so shouldn't the volume displaced by the north icecap actually decrease and thereby lower the sea level? At first I thought that maybe a bunch of snow and ice exists on top of the north icecap that isn't displacing the water, then I remembered that it would still weigh all the ice below it further down thereby displacing more water. I know that much of what's on Antarctica will melt too which might make up for the volume lost, but since it's not completely ice like the north, how exactly will that cause the sea level to rise so much that it's a dangerously urgent matter?
Land ice melts water rises. Are you too stupid to understand that?
