NASA scientists recently spotted a perfectly rectangular iceberg floating among sea ice just off of the Larsen C Ice Shelf in Antarctica. They added that the iceberg’s sharp angles and flat surface indicate that it probably recently calved from the ice shelf.
In an interview with Live Science, NASA scientist Kelly Brunt explains:
We get two types of icebergs: We get the type that everyone can envision in their head that sank the Titanic, and they look like prisms or triangles at the surface and you know they have a crazy subsurface. And then you have what are called ‘tabular icebergs.’
Tabular icebergs are wide and flat, and long, like sheet cake. They split from the edges of ice shelves â€” large blocks of ice, connected to land but floating in the water surrounding iced-over places like Antarctica.
Tabular icebergs form through a process that’s a bit like a fingernail growing too long and cracking off at the end. They’re often rectangular and geometric as a result.