Withi regards to the large ice 'shelf' just about to break away?

Since the volume change in water as it goes from liquid to solid stage is known, it should be straightforward to calculate the amount of water 'contained' in a certain volume of ice. As to destination, melting time, etc.; these are a function of currents in the Southern Atlantic and Pacific Oceans and should be possible to work out to some degree based on historical information.