"iceberg" vs "icesheet"

[Nessie]

Hi, what's the difference between "iceberg" and "icesheet"?
I find the word "icesheet" in this following paragraph and can't seem to find its definition in any dictionaries:

"This is the time of year when icebergs form by breaking away from polar icesheets and move about all over the sea."

Many thanks
Nessie :)
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Sorry seems to be the hardest word...

[Mikesz]

I would imagine the difference is more of a common sense one rather than a technical one. At a basic level, an ice berg is essentially a large chunk of ice that floats along in the water, though can have some part of it (usually only a small part) visible above the water line. An ice berg is technically just a large piece and is free to move about with the currents etc.

An icesheet by contrast, is an amount of ice that sits above as well as below the surface of the water, is attached to something, be that land or another large area of ice and is generally flat and static.

does that make sense?

[Alan]

Hi Nessie,

Think of sheets of ice, rather than ice sheets.

Alan
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[Nessie]

Thanks a lot, Alan and Mikesz :)
There is just one more thing I can't understand: why did Mikesz say "ice berg" instead of "iceberg", and Alan say "ice sheet" instead of "icesheet"?
_________________
:(... something we never have again, I know... I guess I really really know.. :(

Sorry seems to be the hardest word...

[Alan]

Hi Nessie,

I think it's a question of the familiarity of the two words, one with another. To me 'iceberg' is an accepted and joined up word, mainly because 'berg' is not a word used in English on its own. 'Ice' and 'sheet' however can stand on their own and as I don't live in an area in the far north of the world, I would use the two words separately as 'ice sheets' in the same way as I would say 'chocolate cake'. No doubt if I was more familiar with freezing temperatures, I would refer to 'icesheets' as they would be a common feature of the landscape.

Alan
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