Last week, the BAS released Bedmap3, "the most detailed map yet" of Antarctica's landscape beneath its blanket of ice, a ...

It leads into an ice cave that McGregor discovered underneath ... He follows it until it dead-ends and adds another 40 feet to his map. The next day, members of the expedition watch as two small ...

The cave network was much larger than the old maps reflected, with tantalizing passageways high overhead that would require ice-climbing gear to explore. Even as he jotted down dimensions, he started ...

The map was carved in the cave floor and represents a complex water ... which makes it all the more remarkable as this was happening well into the Ice Age. This would have taken a lot of work ...