Primitive Question: Volume

• September 12th, 2007, 02:21 AM
Kolt
Primitive Question: Volume
If you drop an ice cube into a glass of water the water level will rise but when the ice cube melts the water level of the glass remains constant. This is because the mass volume of a cube of ice remains contant as well regardless of its phasing from a solid to a liquid.

Okay so, I know this is probably a very naive uneducated inquiry for most of you in this forum but my question is this: If the glaciers of our arctic oceans are in fact melting then how exactly will that cause an increase in volume of our planets sea level?
• September 12th, 2007, 02:28 AM
Harold14370
Because not all of the ice is floating in water. Some of it is on land.
• September 12th, 2007, 03:18 AM
Kolt
How much? Do you have any knowledge of what the ratio is?

Earth sciences are definitely not my field which is why I ask. But I am still curious.
• September 12th, 2007, 03:56 AM
The Matt
Don't forget the effects of thermal expansion of sea water.
• September 12th, 2007, 04:55 AM
Harold14370
Quote:

Originally Posted by Kolt
How much? Do you have any knowledge of what the ratio is?

No but I think most of the south polar ice is on the continent of Antarctica.
• September 12th, 2007, 05:02 AM
John Galt
Re: Primitive Question: Volume
Quote:

Originally Posted by Kolt
If the glaciers of our arctic oceans are in fact melting then how exactly will that cause an increase in volume of our planets sea level?

There are no glaciers in the Arctic ocean, only floating sea ice. Its melting will have minimal effect on sea level (there is a small volume change involved).
The Greenland icesheet is also, apparently, melting. It will lead to an increase in ocean volume.
The Antarctic is filled with glaciers. These are where the greatest potential problem lies. My recollection is that loss of the Greenland glaciers would raise sea level by around 5m or 6 m. The West Antarctic ice sheet would add about 10m and the East Antarctic ice sheet around 70m.
• September 12th, 2007, 05:17 AM
Twaaannnggg
Well, for all I know the Antarctic ice sheet is just 270 km^3. Just do the math. Take the surface of all oceans and then with simple math compute how much the sea level will rise when you add 270*0.9 km^3 of water. But the numbers ophiolte gave you sound about right.
• September 12th, 2007, 07:58 AM
Kolt
So just to make sure, when you guys say "The Arctic/Antarctic Ice Sheet" you are referring to the water that has been frozen over land - correct?
• September 12th, 2007, 08:11 AM
John Galt
The Arctic ice sheet is sea ice. Its melting, which is imminent and in progress, will have no significant effect upon sea level.
The West Antarctic Ice Sheet is largely at sea, but grounded on a submarine shelf. The East Antarctic and Greenland ice sheets are on land.
• September 13th, 2007, 04:32 PM
KALSTER
In other words the arctic sea is around the north pole and antarctica is around the south pole. The north pole is made up of ice drifting on the water and the ice at the south pole is mostly located on top of the continent antarctica.
• September 14th, 2007, 06:52 AM
Twaaannnggg
Quote:

Originally Posted by KALSTER
In other words the arctic sea is around the north pole and antarctica is around the south pole. The north pole is made up of ice drifting on the water and the ice at the south pole is mostly located on top of the continent antarctica.

Yup, but don't underestimate Greenland.
• September 18th, 2007, 09:57 AM
KALSTER
were there not bigger climate changes in earth's past than global warming? i mean from cold to warmer, and excluding the warming period after the ice ages? could the current global warming episode not be explained by the mechanism that produced the earlyer heatings (if any)?
• September 19th, 2007, 02:21 AM
John Galt
Yes, there were larger changes in the past. Several such changes were associated with mass extinctions.
The mechanisms that produced such changes are still at work, but the role of anthropogenic carbon dioxide is central feature of the current changes.
• September 19th, 2007, 05:02 AM
KALSTER
but is carbon dioxide the main culprit? what about other greenhouse gasses like methane?
• September 19th, 2007, 05:31 AM
John Galt
Quote:

Originally Posted by KALSTER
but is carbon dioxide the main culprit? what about other greenhouse gasses like methane?

Methane has, IIRC, more of an effect than carbon dioxide, pound for pound, but is at a lower concentration and is cycled out of the atmosphere more rapidly, so its net effect is less.
• September 19th, 2007, 06:02 AM
KALSTER
by cycled out , do mean by solar radiation? i read in a post (can't remember where) that it gets destroyed by sunlight and that one of the products are H gas that leaves the atmospere. what was the other product again? i think it was by chinese ben.

on a personal note: what is your profession, if i may ask? you seem to know quite a lot about a lot.
• September 19th, 2007, 08:34 AM
John Galt
Quote:

Originally Posted by KALSTER
by cycled out , do mean by solar radiation?

I'm not sure. I just seemed to recall that the destruction of methane was more rapid than carbon dioxide. For example, there are traces of methane on Mars. These traces indicate one of three things - recent (last 50,000 years) volcanic activity; recent impact by comet; current life.

Quote:

on a personal note: what is your profession, if i may ask?
Training manager in an oilfield service company. Geologist by original qualification.
Quote:

you seem to know quite a lot about a lot.
I've been around a long time. I never forget anything, it's just remembering it that is the problem. :)
• September 19th, 2007, 09:04 AM
Twaaannnggg
Quote:

I'm not sure. I just seemed to recall that the destruction of methane was more rapid than carbon dioxide. For example, there are traces of methane on Mars. These traces indicate one of three things - recent (last 50,000 years)
Think of the different energies of the C=O and the C-H bonds (double vs. single bond etc.) Furthermore think high energy radiation. There you go.

Quote:

Training manager in an oilfield service company
Offshore?? Or in safe distance to the oil riggs?
• September 19th, 2007, 10:02 AM
I get it.

"Twannnnng"?????"guitar"???"guitar player"????etc etc etc?

What I am really trying to say is that that I think the CIA is using me in some type of mind control experiment, offering a science forum questions, to ascertai the reaction speed, looking for codebreakers in this new world order of terrorism.
• September 20th, 2007, 03:20 AM
John Galt
Quote:

Originally Posted by Twaaannnggg
Offshore?? Or in safe distance to the oil riggs?

I worked offshore in my youth, but now I merely suffer the perils of the office desk, the plant floor, or the classroom.
• September 20th, 2007, 05:23 AM
Twaaannnggg
Quote:

Originally Posted by Ophiolite
I worked offshore in my youth, but now I merely suffer the perils of the office desk, the plant floor, or the classroom.

WATCH OUT FOR THE PAPER CUTS!!!! They're fiendish :mrgreen:

And don't staple your finger to the desk.............