icebergs break off into the ocean because the ice accumulates on the glacier making it's mass increase and pushing out the fringes into the ocean. Those break off, drift out and melt. It is too cold down there for any of the ice to actually melt, it just piles up until it breaks off and drifts away...
The latest satelite measures indicate increasing ice packs in Antarctica. Exactly what you would expect from that is icebergs breaking off as the mass expands outwards.
During the ice ages the ice expanding outward from glaciers would not melt and just keep heading south. You had better hope we are not headed for an iceage, because that ice will flatten everything before it, including Gore's half mansions.
Kindof off topic but I was watching Strousel one nite and T. Boone Pickens was on. He mentioned having dinner somewhere with Al Gore. T Boone said Al was eating a cheeseburger. Doesn't he know the truth about global warming and the production of beef? Kindof like Obama preaching about global warming and then flying a personal 747 to Hawaii.