A giant iceberg is on the move. A23a is the oldest and largest iceberg afloat today. It is drifting north, between Antarctica and Argentina.

How big is big?

At 3500 square kilometres, A23a is two-thirds the size of P.E.I. It’s 400 metres thick, just 150 metres shorter than the CN Tower. This iceberg is so huge, it can be seen from space. Viewed from a ship, it fills the horizon, as far as the eye can see.

“It’s a trillion tons of ice. So it’s hard to comprehend just how big a patch of ice this is,” said research scientist Ted Scambos.