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View Full Version : Why do ice at the poles not float away?


quietrain
Nov1-11, 07:11 AM
as per the title. does anyone know?

Andre
Nov1-11, 07:26 AM
Why would you think it doesn't?

http://afishblog.com/wp-admin/images/ice%20berg.jpg

source (http://afishblog.com/?p=39)

But as it floats away, new ice is formed in winter time.

russ_watters
Nov1-11, 07:50 AM
Also, most ice in the southern ice cap isn't floating...

Gannet
Nov1-11, 10:38 AM
Check out http://nsidc.org/arcticmet/factors/land_sea_distribution.html

Read the section about ocean currents

Also, the map shows that the arctic ocean besides being almost completely surrounded by land it has warm surface currents feeding it from both North Atlantic and through the Bering Strait.

AlephZero
Nov1-11, 05:45 PM
does anyone know?

Apparently, the captain of the Titanic didn't...

davenn
Nov1-11, 09:40 PM
Apparently, the captain of the Titanic didn't...

hahaha thats classic, a quote to be remembered, almost tempted to use it in my signature

well done

Dave

quietrain
Nov2-11, 04:30 AM
er

i meant as a whole, why do the ice caps not move away from the poles? not referring to those pieces of ices that break off and float away.

but like what russ said, the ice are not floating? so is it attached to the bottom of the sea floor or something?


land masses don't float away because they are high altitude land, and attached to the earth right? but what about these ice?

or is it like what andre said, where ice keeps moving away and melt , and new ice forms?

then wouldn't the animals like the polar bear be floating away too?

davenn
Nov2-11, 04:36 AM
well for the south pole Antarctica ia a huge landmass, it just happens to be covered in ice and snow --- more so in the winter time. In summer time there are plenty of areas that you can walk on dry land

Dave

PS ... what makes you think it would want to float away enmass ?

TheMadMonk
Nov2-11, 08:09 AM
er

i meant as a whole, why do the ice caps not move away from the poles? not referring to those pieces of ices that break off and float away.

but like what russ said, the ice are not floating? so is it attached to the bottom of the sea floor or something?


land masses don't float away because they are high altitude land, and attached to the earth right? but what about these ice?

or is it like what andre said, where ice keeps moving away and melt , and new ice forms?

then wouldn't the animals like the polar bear be floating away too?

My bold.

Ice at the south pole is partially atop a large landmass.

dmm
Nov2-11, 04:30 PM
It is floating. But it's already at the top of the world. (This answer brought to you by "When good physicists go bad.")

Seriously though: a) There's no net force to make it drift away from the north pole, en masse; b) There are some islands in the way; c) Anything that drifted too far south would melt, so you wouldn't notice any net drift; d) I wouldn't be suprised if melting at the edges provides a net force northwards (but I haven't worked that out); e) any net drift southwards would violate conservation of angular momentum (sloppily worded, but think about it); and f) Santa Claus doesn't let it drift (not to mention Kal-El).

davenn
Nov2-11, 06:08 PM
My bold.

Ice at the south pole is partially atop a large landmass.

As I had already said ;)


D

TheMadMonk
Nov3-11, 07:15 AM
As I had already said ;)


D

I didn't quite understand it at first, I struggle with my English. :redface:

Redbelly98
Nov3-11, 10:04 AM
Do a google image search on: arctic polar cap

You'll see many images similar to the ones below, which show the ice mass around the north pole is connected to land and not simply floating:

http://spaghettitesting.files.wordpress.com/2008/09/polarcap.png?w=480&h=282

http://marinesciencetoday.com/wp-content/uploads/2009/04/arctic-ice-satellite-picture-300x168.jpg

Nik_2213
Nov3-11, 02:30 PM
"... so is it attached to the bottom of the sea floor or something?"

If the ice-cap / glacier is thick enough, it remains grounded beyond the 'natural' coastline. If such an ice-shelf thins enough to float, warming sea-water can get underneath and may cause rapid melting, flexing, fracturing and 'calving' of mega-bergs.

Xnn
Nov3-11, 06:08 PM
Most ice in the arctic ocean is drift ice. It is floating and moves according to the winds and currents. Sea ice is another word for drift ice.

Ice shelves are also technically floating although they are attached to the land so they don't move. Ice shelves are called "fast ice", because it is fastened to the land.

The reason only a limited amount of sea ice moves out of the arctic is because there is a lot of land encircling it and because the largest current goes in a circle; the Beaufort Gyre.

quietrain
Nov5-11, 06:20 AM
oh cool

so the ice caps are acutally ice on top of land masses?

ic thanks

Ophiolite
Nov5-11, 08:40 AM
No. The bulk of the southern ice cap is atop a land mass. The bulk of the northern ice cap is thin, floating and constrained by the surrounding land masses and ocean currents.

quietrain
Nov6-11, 08:19 AM
No. The bulk of the southern ice cap is atop a land mass. The bulk of the northern ice cap is thin, floating and constrained by the surrounding land masses and ocean currents.

oh, so theres no land in the north?

so i saw this documentary about the great melt, it says ice will melt during some time of the year.

so when it melts, wouldn't the north pole ice start to float around?

DaveC426913
Nov6-11, 09:05 AM
oh, so theres no land in the north?

so i saw this documentary about the great melt, it says ice will melt during some time of the year.

so when it melts, wouldn't the north pole ice start to float around?Indeed it does. Icebergs float all down the coast of Newfoundland an Labrador. Some are very large. Even larger ice sheets move and bump against each other. But as a whole, the entire Arctic ice sheet is not entirely isolated from land. It encounter shorelines and runs deep where it encounters the ocean floor.

D H
Nov6-11, 11:14 AM
so when it melts, wouldn't the north pole ice start to float around?
The ice in the arctic is always in motion.

Here's an animated gif that displays this motion for the last 12 months (follow the link; the image is a bit too big in terms of number of bytes to display inline):
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf_nowcast_anim365d.gif

quietrain
Nov6-11, 10:05 PM
wow thanks interesting stuffs

DrClapeyron
Nov8-11, 10:54 PM
I don't think there is a force large enough to singl-handedly move a large part of the northern pole away from its present position. But there are a number of forces acting to keep the ice at pole, including gravitational drift.