Strange Rectangular Iceberg Spotted In Antarctica Looks Eerily Artificial

Earlier this month, NASA spotted an unusually-shaped iceberg break off from an ice shelf in Antarctica. The perfectly square iceberg reportedly broke off from the Larsen C ice shelf that also produced the A-68 iceberg last year. ( NASA | Twitter )

A massive slab of iceberg that recently separated from the Larsen C ice shelf in Antarctica is so geometrically perfect that it almost looks unreal.

Square Iceberg

NASA shared the photo of the iceberg that has since become viral. On Twitter, it fetched over 3,000 retweets, 6,000 likes, and hundreds of responses. It has captured the imagination of many, with some theorizing that it was made by aliens.

However, there is no giant conspiracy around the perfectly rectangular slab of ice. It was a naturally occurring phenomenon called tabular ice which, unlike the iceberg that sank the Titanic in 1912, has flat tops and steep sides.

Sometimes, these tabular icebergs are gigantic in size, measuring hundreds of miles in length and hundreds of feet in height.

From yesterday's #IceBridge flight: A tabular iceberg can be seen on the right, floating among sea ice just off of the Larsen C ice shelf. The iceberg's sharp angles and flat surface indicate that it probably recently calved from the ice shelf. pic.twitter.com/XhgTrf642Z — NASA ICE (@NASA_ICE) October 17, 2018

NASA spotted the on Oct. 16 during one of its IceBridge Flights, a program that tracks the global climate system. Based on its smooth edges, the agency believes that it has not been long since the iceberg separated from Larsen C in Antarctica.

"What makes this one a bit unusual is that it looks almost like a square," said Kelly Brunt, an ice scientist from NASA.

From the photo alone, it is impossible to determine the size of the iceberg, but Brunt estimated that the tabular iceberg is about a mile across. Only about 10 percent is visible above water.

Splitting Ice Shelves Of Antarctica

Larsen C, an ice shelf, also produced the A-68 iceberg in 2017. In September, after getting stuck for over a year, the iceberg has turned around, suggesting that it is ready to move.

Finally, movement at the western end of Iceberg A-68? Yesterday's @NASANPP satellite image shows A-68 is no longer abutting Larsen C Ice Shelf, suggesting it may no longer be grounded near Bawden Ice Rise; the eastern end continues drifting counter-clockwise in the Weddell Sea pic.twitter.com/ulTB2QYYHy — The Antarctic Report (@AntarcticReport) September 2, 2018