What would Antarctica look like if it all melted?

Ella Gilbert works for British Antarctic Survey, so Chris Smith put this question to her...

Ella - I'd say it would pretty much look like a lump of rock, probably. I think the real question we should be asking is what would the rest of the world look like? Antarctica is covered in, on average 2.7 kilometres of ice, so it's pretty thick, in some places it's up to four kilometres thick. And if all of the ice was to melt, it would raise global sea levels by 58 metres. So I think that's probably the framing that you should be going for. What would the map look like if all of Antarctica melted and ended up in the sea.

Chris - Because there's one other consideration, which is that that 2.7 average depth of ice kilometre, average depth of ice covering Antarctica is gravitationally very active. So it's pulling a lot of sea water around Antarctica, which would otherwise be redistributed around the Earth. So as well as the pure physical effect of when you melt that ice and it goes into the sea and tops up the oceans and pushes up the levels, you lose that gravitational attraction. So the bulge of water that's currently sitting around Antarctica is also gone.

Ella - Yeah. And it affects different parts of the world differently of course as well.

Chris - Yeah. So returning to the question, just to do it justice, you'd basically see a hunk of rock because there's a hunk of rock. There's a volcano there as well though, isn't there? Mount Erebus is there, so you'd probably see a mound of rock with a volcano is the bottom line, isn't it?

Ella - Some bits are below sea level. So in the West Antarctic, some are below sea level and you'd get a few, few little lakes. But mostly it's just a bunch of rock.

Chris - Ella. Thank you. I mean it used to be a green and pleasant land, didn't it? Once upon a time it was connected to Australia and Tasmania and there were big penguins and forests, and it was warm and balmy because the ocean couldn't circulate and make it cold? But that was a little while ago. Thank you for that. Ella.