Well here's something you don't see everyday: an iceberg so unbelievably geometric in shape you'd think it was deliberately carved with a huge chainsaw. The calving is accelerated when warmer temperatures cause meltwater to trickle into the splitting cracks and widen the ice shelf division.
He's a research scientist with NASA's Operation IceBridge, the group that took the stunning photo, and is based at the NASA Goddard Space Flight Center. Sitting amid a chaotic jumble of floating ice, it looks perfectly rectangular, as though it was deliberately cut.
NASA's ongoing, decades-long survey of polar ice has yielded some truly incredible photographs over the years, but one recent still captured what appears to be a perfectly, nearly impossibly rectangular iceberg.
"That shape is not hugely surprising", said Walker.
These are flat and long and form by splitting away from the edges of ice shelves.
"A tabular iceberg can be seen on the right, floating among sea ice just off of the Larsen C ice shelf", NASA's department of cryospheric sciences tweeted. "And then you have what are called 'tabular icebergs'". The iceberg represents one trillion tons of ice.
"The iceberg's sharp angles and flat surface indicate that it probably recently calved from the ice shelf", according to a statement from NASA.
And as with all icebergs only 10% of it is visible; the rest if buried below the surface of the water.
That was not the only shape that scientists spotted last Wednesday.
The rectangular mile-wide block of ice was seen off the east coast of the Antarctic Peninsula near to the Larsen C ice shelf.
That iceberg measured about 2,300 square miles, as NPR's Geoff Brumfiel reported.
Operation IceBridge's mission is to image the planet's polar regions to better understand how ice has changed and shifted in recent years.