Giant cracks push imperilled Antarctic glacier closer to collapse

What I hadn't realised (due to not having thought heavily about it) is that it's NOT just about the amount of ice melting that threatens sea levels, but the weight and location of the ice before it melts.

The Antarctic landmass is weighed down by millions of tons of ice, and when (if?) that melts in significant amounts, the land will rise up due to no longer having that frozen mass on top of it. This will cause even more water to be displaced as Antarctica becomes much bigger, and higher than the current 'sea level'. Like throwing pebbles in a cup, this causes the overall sea-level to rise, in addition to the impact the melted ice has.