Strange Rectangular Iceberg

NASA Spots Strange Rectangular Iceberg in Antarctica

This is called a 'tabular' iceberg, and it's actually surprisingly common.

By Avery Thompson
NASA/ICEBRIDGE

Floating off the coast of Antarctica is an iceberg, but not any normal iceberg you’ve ever seen. This particular iceberg is completely flat at the top, with square sides and right angles. It looks like a giant sheet cake floating in the ocean. While your first instinct might be to assume this particular chunk of ice is human-made, in reality it’s completely natural.


The cake-shaped iceberg was photographed on October 16 by NASA’s IceBridge program, which routinely flies planes over the poles to take photos and study how these remote locations are changing. In the past, these flights have mapped Greenland’s ice sheets, identified collapsing ice shelves, and spotted mysterious holes in the Antarctic ice.

In this case, the IceBridge planes spotted the strangely-shaped iceberg floating near the Larsen-C ice shelf, and scientists suspect that the ‘berg recently broke off from there. Larsen-C made the news in July of last year when a giant iceberg the size of Long Island separated from the shelf. The iceberg that formed last week is smaller but still pretty large: it measures around a mile across.

So why is it so rectangular? Rectangular icebergs aren’t even all that unusual, although this one is a bit more rectangular than most. A typical large iceberg that breaks off an ice shelf, called a ‘tabular’ iceberg, will have a flat top and steep sides like the one spotted by IceBridge. In fact, most icebergs look something like this initially; it’s only after the iceberg melts and breaks apart that they become the irregular-shaped icebergs we’re more familiar with.


A similar tabular iceberg photographed in Antarctica in 2016.
WIKIPEDIA/GODOT13

It’s also likely that this iceberg isn’t the perfect cube it appears to be in the photograph. Most of the iceberg is underwater, of course, and even the bits that are visible aren’t all inside the frame. Still, this just shows that nature is able to create strange and unexpected things even with something as simple as frozen water.