well i believe that if the ice caps do start melting we would get about a 200 feet water rise in the world.(will islands disapear?) but some people are saying that when ice cubes melt in a cup of water, the water does not rise. can you explain to me how both these theory's work and are correct or incorrect.
2007-07-15 12:54:03 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
Sea ice does not lower the sea level because it displaces its own mass in water. What lowers sea level is big LAND glaciers such as exist in Greenland and Antarctica.
Here's how it works. A land glacier forms when the seasonal snow pack in a region does not fully melt during summer. Over time the snow builds up, until eventually you can get a layer of ice more than a kilometer thick, such as exists in Antarctica (the ice is what the bottom layers of the snow pack turn into under pressure from the upper layers). As this happens the snow that becomes incorporated into the ice cap is taken out of the water cycle. Since most of the water vapor in the atmosphere comes from evaporation from the oceans the glacier is, essentially, taking water out of the oceans as it forms.
This is the reason that during the ice age, when Canada, Siberia, and the North Sea Shelf were covered with similar huge land glaciers, the sea level was about 120 meters lower than it is today. When all that ice melted 10,000 years ago it raised the sea level to what it is today.
Right now Antarctica is covered by a layer of ice 1.6 km thick. Greenland's ice cap is much smaller, but it also locks away water that would otherwise be in the oceans. If both caps were to melt the water thus liberated would raise the sea level another 80 meters.
In case you are interested, here is a site with a neat interactive map that lets you raise and lower the sea levels to see what the continents would look like. Raise the sea level 80 meters to see what would happen if all the polar ice melted.
http://merkel.zoneo.net/Topo/Applet/
2007-07-15 13:06:44 · answer #1 · answered by Somes J 5 · 2⤊ 0⤋
the second theory would require that the ice is floating, in which case that would be right in the case of the cup. ice (and any other substance that floats) only displaces the amount of water that it weighs. in other words, pretend that an ice cube that is 1.1 cubic centimeter weighs 1 gram (i know im a little off on this but this is pretend) well when it melts, it will still weight the same, because its mass doesnt change. therefore it will turn into 1 gram of water, but will only be 1 cubic centimeter of water. now... pretend that ice cube if floating in water. while its still ice, it displaces 1 gram worth of water, in other words 1 cubic centimeter. the other 0.1 cubic centimeter of ice will be above the water. however, once the ice melts, it will just contract and "lose" that 0.1 cubic centimeter that was above the water (that make sense at all?)
the ice at the poles isnt really floating. its mroe like frozen snow and rain that landed on islands. scientists say that the 200 feet of rising will occur more because of the expansion of the trillions of billions of gallons of water in the oceans than the melting of the caps anyways. (you might not have heard this theory, but it actually has grounds). all substances expand with heat (except ice and water in between temperatures of 32 and 34. at all other temperature however, they follow the rules), and with the much water in the oceans, its bound to expand enough for us to notice. i have my doubts about how much heat would be required to heat up that much water though....
2007-07-15 13:08:04 · answer #2 · answered by Fundamenta- list Militant Atheist 5 · 2⤊ 0⤋
People are wrong when they say that when ice cubes melt in a glass of liquid. Same concept applies when you are talking about polar ice caps. Yes it will cause i rise in water level and it will cause islands to be destroyed and possibly coastal areas. This is a serious issue( polar ice caps melting).
I hope i helped you out.
2007-07-16 10:33:19 · answer #3 · answered by diablo_blaze7 2 · 0⤊ 0⤋
If an ice cube melts, then there is less water in the glass, not the same. Frozen water takes up more space, so it would depend on just what is melting. . .There used to be theories that if the ice caps melted, the water level in the world would stay the same-but not because frozen water takes the same space as regular water. . .
2016-05-18 21:24:54 · answer #4 · answered by ? 3 · 0⤊ 0⤋
Hi. Ice that is floating does not raise the water level when it melts. Ice that is on land melts and is drains to the water so the level rises.
2007-07-15 12:59:45 · answer #5 · answered by Cirric 7 · 4⤊ 1⤋