Mysterious 'perfectly rectangular' iceberg spotted floating in Antarctica

It looks so perfect that it seems Photoshopped, but a strange, perfectly rectangular iceberg near Antarctica is a natural phenomenon, NASA scientists say.

The mysterious slab-like iceberg, up to a mile wide, was spotted near the Larsen C ice shelf, and the sharp angles hint that it broke off very recently.

It is described as a ‘tabular iceberg’, with steep sides and a flat top, typically formed by ‘snapping off’ from an ice shelf, experts say.

Many of the largest icebergs on record have formed this way.

“A tabular iceberg can be seen on the right, floating among sea ice just off of the Larsen C ice shelf,” NASA said.

The perfectly rectangular iceberg in Antartica. Source: NASA ICE

“The iceberg’s sharp angles and flat surface indicate that it probably recently calved from the ice shelf.”

Calving describes the process of ice chunks breaking off from glaciers.

NASA scientists captured the image on an IceBridge flight, an airborne survey of polar ice.

“What makes this one a bit unusual is that it looks almost like a square,” NASA scientist Kelly Brunt told LiveScience.

Another example of a tabular iceberg in Antartica. Source: Getty Images.

Last year, the iceberg A-68 broke off Antarctica’s Larsen C ice shelf after years of cracks spreading across the ice.

The ice shelf is over 300 metres thick and floats on the edge of West Antarctica. The calving of the huge iceberg reduced the size of the ice shelf by 12 per cent.

“Sea ice to the east and shallow waters to the north kept this giant berg, named A68, hemmed in,” Scientists from the European Space Agency wrote in September.

“So for more than a year it wafted to and fro, but never left its parent ice shelf’s side. Strong winds blowing from Larsen C have finally given it the push it was waiting for.”

These winds pushed the southern end of the berg out into the Weddell Gyre, a circulating ocean current system, in early September 2018.