[KayEss]

Once they fall into the sea the displacement occurs. It doesn't matter after that how long they take to melt, all that matters is that they fall off land and into the ocean.

So melting is an issue only for ice that melts on land and then flows into the oceans because that represents new water volume.

[oldandtired]

It's not that simple. You must take into consideration the amount of ice that is deposited onto the ice mass from snow and condensation of water vapour.

If the rate of deposit is greater than the rate of calving then there is a nett addition to the ice mass. If the rates are equal, then you have steady state. If the rate of calving is greater then you have a nett loss.

This has to be looked at over a longer period of time to see what the variation is in the data.