Encyclopedia of Science

[george99]

I don't understand the explanations by glacier scientists.

I've read articles that explain formation of glaciers; they say the increasing mass causes them to move down by gravity.
Place an ice cube at the top inside of a large bowl; it slides down to the bottom. It will not slide down if it's frozen to the top ridge.
I assume the mass of a glacier moving down a valley is greater than any physical attraction at the top part. In other words, it's a moving object.

I've seen diagrams showing the extension of white stuff (glaciers etc.) from the Arctic southward to the Great Lakes area in North America.
I can understand how lower temperatures could cause additional white stuff. But that doesn't make it move; there's just more of it!

"Going south" (from the North Pole) is not the same as going down a valley.

Shed some light on this?

[treelover]

Glaciers just happen to be ice. That they are ice isnt really important.
To be politically correct, 'faeces' rolls downhill. If instead of ice the material was 'earth' it could still go downhill.

The Key to this movement is lubrication.

Dry earth is mostly stable, wet it and you can get a mud slide. The mud is slippier ( and heavier ) than the dry earth.
With snow falling on snow, the upper snow presses down on the lower snow, compacting it into ice, the ice at the bottom and sides of the glacier is under massive pressure from the ice and snow above it vertically and from up the valley horizontally. Ice under pressure melts... into water water is the lubricant here and where water is trapped between the ice and the rock it forms a water slide. put a large sheet of plastic on a lawn wet it, take a run up to it and jump onto it and you'll slide forever. Try it without the water first. if you are lucky, your feet will grip the plastic and you will gather plastic as you slide across the grass - if your not, you'll stick to the plastic, the plastic will stick to the ground and your head will overtake your feet and you'll fall flat on your face - ouch!!

Compriz?

BoB