World's biggest canyon under Antarctica?

[Brian G Turner]

The BBC reports that scientists are beginning to see evidence of a giant canyon system beneath the Antarctic ice sheet that could dwarf the Grand Canyon:
'Gigantic chasm under Antarctic ice' - BBC News

A vast, previously unrecognised canyon system could be hidden under the Antarctic ice sheet.

Hints of its presence are seen in the shape of the white continent's surface, in a largely unexplored region called Princess Elizabeth Land.

If confirmed by a proper geophysical survey - now under way - the winding canyon network would be over 1,000km long and in places as much as 1km deep.

Perhaps more exciting is that later this year, scientists should have - and be able to release - a full radar map of Antarctica, showing the complete topography of the landmass under the ice.