As it turns out if you can measure changes in distance between the two satellites, you can get information about what's underneath and what's causing those changes. And you can get information when you fly over the ice sheet about the mass change of the ice sheet.
The changes we are seeing are probably a good indicator of the changing climatic conditions there.
The overall balance of the Antarctic ice is dependent on regional changes in the interior and those in the coastal areas. The changes we are seeing are probably a good indicator of the changing climatic conditions there.