Here's how perfectly rectangular icebergs are formed

• A perfectly rectangular iceberg was spotted by NASA scientist Jeremy Harbeck in October off of the Larsen C ice shelf in Antarctica.
• This tabular iceberg is naturally occurring - the flat top and sharp corners indicate that the iceberg was recently formed.
• In the video above, marine glaciologist Dr. Jan Lieser explains why this iceberg won't stay the same for long.

Following is a transcript of the video.

Narrator: Does this image look Photoshopped, fake, or even created by aliens? You wouldn't be alone in thinking that. But, you would be wrong. This is actually a naturally occurring phenomenon. What you're seeing is a tabular iceberg. Tabular icebergs form a plateau, with a flat top. Unlike non-tabular icebergs, which usually have a rounded top. This iceberg was photographed in October, by NASA scientist Jeremy Harbeck. Most icebergs look similar to this at first, although this one is exceptionally rectangular. So how are these perfect icebergs formed? All icebergs form when a piece or sheet of ice breaks away from a large ice shelf or glacier. And because of ice's innate crystal structure, it tends to break along straight lines.

Dr. Jan Lieser: The icebergs that we usually see are weathered. They get beaten up by winds and waves and they lose bits here and they shed a bit of, shed a piece there. This is a recent carving event.

Narrator: This iceberg broke off of the Larsen C Ice Shelf in Antarctica. Over time, wind, waves, and warmer water will degrade the iceberg and break it apart, eventually turning it into the rounded shape you're probably more familiar with.

Dr. Jan Lieser: These regular shapes, that won't stick around for long. If we look for this iceberg today, which is only a couple weeks after it was originally spotted, it won't look like that anymore at all.

Narrator: As this tabular iceberg floats away and changes shape, it won't resemble the iconic iceberg in the photo. But it will live on, thanks to social media.