You may be thinking of icebergs.
Ice bergs.
icebergs
A lage chunk of ice floating in the water, most of it is in the water.
Floating ice is already in the water, so its melting causes no rise in lake levels.
A "slow moving river of ice" is a glacier. A slow moving chunk of ice floating down a river is a "floe".
GlacierLarge masses of floating ice are called Icebergs. There are different types, but that is the general term applied to those large masses of ice.
B-15 was the largest iceberg ever recorded. The large chunk broke off of Antarctica and was roughly the size of Jamaica.
There is no logical or scientific reason why a chunk of ice a billion kilometers away will change human behavior more than antarctica does.
Chunk-a-chunk Big chunck Chunk-a-chunk Big chunk Open wide for Chunky!
Icebergs change size and shape constantly. When a fissure or crack develops and a portion breaks off it is called a floe. Changes in icebergs are determined by climate, pressure, force and temperature.
Technically no-one owns any land in Antarctica. Various countries have staked claims in Antarctica but these have not been universally recognised and after the 1959 Antarctica treaty, which essentially prevented any future claims, Antarctica's status has been pretty much unchanged - lots of people claim to own chunks of it but everybody else says they don't. You could say the Australians because they claim the largest chunk of it...
Um, no. The moon, Pandora is like all other moons, and is a giant chunk of rock floating around a planet, with no life whatsoever.