Many of these get hung up since there are many areas they have to drift through that are not deep enough, so they get stuck and just melt in place. This chunk is about 2/3 the size of Big Island in Hawaii. There have been other bigger ones. I think there is one relatively large sized (or whats left of it) one near New Zealand. You have to realize the oceans are really huge and hitting one of these is highly unlikely.

The bigger question is how the remaining shelf breaks apart; people are not sure if its more stable or more unstable after this calving; with huge ice areas its not always easy to predict.