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Have you seen a topographic map of the Antarctic surface under the ice? It's pretty creepy: about half of it is below sea level. It's weird to think there's ice piled kilometers high on top of it. Of course, if/when all that ice melts, most of it would pop above (now higher) sea level, due to isostatic rebound.

http://www.zonu.com/detail-en/2009-11-18-11159/Antarctica-to...

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Isostatic Rebound: I didn't know it existed! According to http://en.m.wikipedia.org/wiki/Post-glacial_rebound , it could be in the order of magnitude of 1.8cm per year at some places of Antartica and Canada.

it could be in the order of magnitude of 1.8cm per year at some places of Antartica and Canada.

Here’s a visualization of elevation over time recorded by a GPS observatory at Baker Lake, Nunavut, relatively near the fastest modeled rebound in Canada: http://www.sonel.org/spip.php?page=gps&idStation=2407

By eyeball, that’s 0.08 m over 2003–2011, or just about 1 cm/year. (Notice the tabs on the bottom: the x and y velocities also show clear trends. That’s continental drift. And when the news says something like “the earthquake permanently moved the ground almost two feet south”, the data comes from observatories like this one, among other methods.)

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