Query For The Curious (Science!)

[ftpiercecracker1]

By now we've all heard about the melting polar ice caps and how the sea levels will rise causing all sorts of mayhem, right?   Well, the other day i was daydreaming, again, and a rather perplexing conundrum popped into my noodle.

 

Back from my basic chemistry class in HS i learned that water is a very unique substance. Unlike nearly all other materials its solid form contains less mass than does its liquid form. It is for this reason that when water freezes it floats, because it becomes less dense than its liquid counter part and essentially why life can exist in areas that are below freezing for long periods of time.

 

The important thing to remember is that ice contains less water than liquid. With that in mind lets conduct a little experiment.  Lets say we have a contain (shape and volume do not matter) and can somehow fill it entirely with ice perfectly to the rim, without the container deforming. If we were to allow the ice to melt completely wouldn't the liquid water level be significantly lower than the rim of our container?

 

Lets increase the size of our experiment to say the size of an ocean and lets drop a few ice cubes (polar ice caps) into it. While our 'ice cubes' are solid they are of a larger volume and thusly displace more water. As the ice (less dense) begins to return to water (more dense) wouldnt the water levels go down and not up???

 

Even if what i am saying is true, the melting of the ice caps is definitely not a good thing. From the loss of habitat to the massive influx of fresh water into the oceans and its possible repercussions, it is something we should be trying to circumvent.

 

Cliff notes: The melting of the polar ice caps would could sea levels to drop instead of rise.

 

 

 

 

With all of this said you may begin to think i am not a believer in global warming, quite the contrary actually. I believe something is happening and i also believe we (humans) are directly to blame.

 

 

Hope you find this as intriguing as i did. :thumbsup:

 

 

FPC,

out.

[jimoshel]

At present the ice caps are ABOVE the water line so they have no influence on it. When they melt the water will flow down and into the ocean. The obvious solution is for everybody to start drinking more booze, getting the ice for them from the ice cap. :cheers:

[MJRemi]

Something else to ponder is the ice caps are fresh water melting into less dense sea water. The fresh water sinks down into the oceans and can alter habitat and ocean currents. Who knows what the long term effects can bring.

[ftpiercecracker1]

Something else to ponder is the ice caps are fresh water melting into less dense sea water. The fresh water sinks down into the oceans and can alter habitat and ocean currents. Who knows what the long term effects can bring.

 

My thoughts exactly, i believe experts have done research on this with some rather disturbing results.

[dasbulliwagen]

The ice caps aren't causing sea levels to rise. Its the rising number of boats that are in the water displacing the water causing it to rise. We just need to get rid of all the boats.

[gogmorgo]

If you take an ice cube and let it melt, the mass remains the same between the ice and water. The difference is in density. Ice is less dense than water, because it expands when it freezes. In terms of buoyancy, ice floats because it is less dense, but because it's less dense, not all of it is below the surface of the water. Only about a third of an iceberg is visible, and so on. A floating object displaces it's own mass in water. Ice displaces less water than it's total volume because it is less dense, but once the ice returns to water (at a similar temperature) the ice water displaces the same amount of water as when it was ice.

TL;DR: If you have ice floating on top of water and the ice melts, it doesn't change the level of the water since the ice "shrinks" as it returns to water, and all the melt water will fit into the same space as the ice that was below the water line.

 

The issue with rising sea levels is that the polar ice caps are largely not floating. The Antarctic and Greenland ice sheets are almost entirely on land, and are miles thick in places. It's a lot of water. Some estimates have it to be 70% of the world's total fresh water, roughly 2% of the total water on the surface of the Earth. The sea level will definitely rise if it all melts and runs downhill into the oceans.

Saying global warming is triggering this melt is a bit of a stretch though. The warmer atmosphere holds more water vapour, which leads to more precipitation and actual thickening of the Antarctic ice sheet. Also, a lot more land would become uninhabitable due to rising temperatures and expanding deserts than due to rising seas... the issue is just that we tend to settle predominantly along trade routes, and particularly in port cities, so the most dense human populations tend to be along coast lines.

National Geographic has a cool resource on their website about rising sea levels. http://ngm.nationalgeographic.com/2013/09/rising-seas/if-ice-melted-map

[Keyav8r]

Global warming/cooling is a cyclic phenomenon that, according to historical geologists, has occurred more than once since the planet was formed. Remember the "Ice Age"? Which was presumably preceded by and followed by a warmer climate (had to be warmer before and after for there to be a noticeable contrast). I don't believe there were too many factories, power plants or automobiles spewing out CO2 (or whatever gases are currently being blamed), as there weren't too many, if any, tool using humans around in those days to build them. Maybe it was all the herbivore animals emitting methane digestive gases?

That's my humble, and not politically correct, opinion. You may choose to disagree and attempt to refute my opinion, but at my rather advanced age I'm pretty damn set in way of thinking so you'd be wasting your time to try to reason (argue) me around to your point.