http://hyperphysics.phy-astr.gsu.edu/hba...
This means when fresh water passes 0C it contracts slightly until it is thawed then begins to expand again due to thermal expansion. Sea water, however, freezes at about -2C depending on the salinity of it.
http://www.onr.navy.mil/focus/ocean/wate...
The melting of sea ice such as that over the Arctic, however, is not expected to increase or decrease sea level much as pointed out above. Land ice melting is what is expected to increase sea levels as well as thermal expansion.
Kano: Any liquid with a make-up of positive and negative charges similar to that of water will expand as they freeze.
http://www.helium.com/items/453167-subst...
http://www.webpages.uidaho.edu/geol309/n...
Other substances that expand when freezing are silicon, gallium, germanium, antimony, bismuth, plutonium and so on.
Water expands yes but the water level remains EXACTLY the same for sea ice. If you lock up water on land with expanding glaciers then the sea level could drop. During the last Ice Age water levels were more than 100' lower than they are today. If the existing land based glaciers were to melt then sea levels would rise because you are taking land based water and putting it in the ocean.
Free floating ice when it freezes has no impact on sea level, because it's volume is already accounted for.
You can do a simple experiment to show this is true.
Fill a glass with ice. Then pour water into the glass until the glass slightly overflows.
As the ice melts the volume of water will remain the same, it will not continue to overflow as the ice melts. The level will stay right at the rim of the glass even after it has all melted.
The volume of ice that is floating above the water level is the expanded volume but as it melts, the liquid volume is not disturbed.
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"When water freezes it expands about 9% ... "
Does this mean that sea levels will rise at the poles when they gain more ice?
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No, because 9% of the ice will be above the sea level and thus not in the water. If you put a big rock on the ice and submerged it, then yes in that case it would raise the levels.
Water does expand when it freezes, depending where this water is will determine what happens to sea-levels.
If the water is land-based, such as Antarctica or Greenland, then the expansion of the water will have no effect as it’s not in the sea. If the ice melts then it flows as rivers and streams into the sea and causes sea-levels to rise.
If the ice forms as ice-sheets or sea-ice (as in the Arctic) then this is ice that’s floating on top of water and so it’s already displacing it’s own mass; when it melts it has no effect on sea levels. When new ice is formed from precipitation or the freezing of the sea, then almost all the expansion is upwards into the air, this is because the air offers far less resistance to expansion than the water does.
If more mass is added to the underside of existing ice then all that happens is the ice mass floats that little bit higher as it has more buoyancy. There is no effect on sea-levels, X amount of water will displace X amount of water whether it’s in liquid or solid form.
Archimedes figured out a long time ago that the answer to either of your questions is NO.
Unless you transfer the ice from on top of the water to/from on top of the land - such as melting ice running into the sea.
I agree with the previous answers but I do believe that the ice that does float above the water displaces air which has mass. Although it is miniscule by comparison to the weight of liquid water, it does make it so you can't use the word "exactly" but for all practical purposes can be ignored.
Others have given the answer but all I wanted to say was that I can't believe that people gave a thumbs down to those who obviously understand Archimedes' Principle.
Idiots ... I think those thumbs-down should remind us that there are pig-ignorant people out there who haven't a clue about even the most basic physics and yet feel they are sufficiently knowledgeable to proclaim their opinions on the validity or otherwise of conclusions by professional scientists working in climatology.
As ocean water warms from ice to 4'C, it shrinks, so sea levels should be going down now in polar regions.
Surprisingly, sea levels do rise more at the poles when ice grows .. or sea levels do rise more away from the poles when polar ice melts. But the reason is not because ice expands, it is because of gravity. Glaciers have gravity, and as they diminish their gravitational pull diminishes and water moves away. Gravity is one major reason that sea level rise is not the same everywhere.
http://hyperphysics.phy-astr.gsu.edu/hbase/Chemical/waterdens.html
"Water has the highest specific heat of any common substance, 1 calorie/gm °C = 4.186 J/gm °C. This provides stability of temperature for land masses surrounded by water, provides stability for the temperature of the human body, makes it an effective cooling agent, and many other benefits. The high heat of vaporization of water makes it an effective coolant for the human body via evaporation of perspiration, extending the range of temperatures in which humans can exist."
http://www.newton.dep.anl.gov/askasci/eng99/eng99358.htm
"When water freezes it expands about 9% ... "
Does this mean that sea levels will rise at the poles when they gain more ice?
Nothing to do with the answer, I just find it amazing that water expands when it freezes, it is the only substance that does that.
The level of water never increase or decrease it remain the same
