A few days ago NASA's IceBridge project hit the news, but not for any of its impressive scientific observations. Instead, a casually tweeted photo of a strange rectangular iceberg captured people's imagination. Now, NASA has offered up a few more shots, and video, of this unusual sight, helping explain this common yet rarely seen phenomenon.

Known as a tabular iceberg, this sharp-angled piece of floating sea ice was seen during an IceBridge flight on October 16th. The flight was specifically surveying changes in glaciers draining into the Larsen A, B and C embayments. This particular iceberg, seen near the Larsen C ice shelf was spotted by scientist Jeremy Harbeck during the flight.

"I thought it was pretty interesting; I often see icebergs with relatively straight edges, but I've not really seen one before with two corners at such right angles like this one had," explains Harbeck.

The Larsen C ice shelf is a hotspot of activity in Antarctica, having made major news last year with one of the largest icebergs ever observed breaking off the shelf. The iceberg was dubbed A68, and this latest IceBridge flight was flying towards the massive stretch of floating ice.

"I was actually more interested in capturing the A68 iceberg that we were about to fly over," says Harbeck, "but I thought this rectangular iceberg was visually interesting and fairly photogenic, so on a lark, I just took a couple photos."

Despite the uncannily sharp right angles on the iceberg giving the impression it must have artificial origins, this is in fact a natural formation, and even a quite common one. The sharp angles on this particular iceberg suggest it very recently calved from a larger body of ice. Wind, water and temperature have not had time to degrade its crisp lines, so the rare timing of the IceBridge flight allowed a view of an exceptionally pristine tabular iceberg.

Subsequent aerial photos released by NASA (which can be viewed in our gallery) from that same IceBridge flight reveal this particular iceberg is just one of many that seem to have calved off from A68, now referred to by the researchers as an "ice island."

Take a look at a video below, shot from the nose of IceBridge aircraft, as it approaches and flies over the tabular iceberg.

Source: NASA

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