(CNN) - Satellite imagery from NASA shows a huge iceberg is about to break off of Antarctica.
On the Brunt Ice Shelf, a crack stretches from south to north.
Even though the crack has been there for about 35 years, it recently started growing in size northward at a rate of about two and a half miles per year.
That means the big chunk of ice to the left of it, a surface area about twice the size of New York City, will break off and become an iceberg.
Researchers are worried about how that will impact the remaining ice shelf, where scientists are currently stationed. The rifts may destabilize the entire shelf.
The scientists’ base of operations has been rebuilt and relocated over the years, and it’s had to be closed down twice in recent years because of changes in the ice, NASA said.
Ice breaking off from shelves is called calving.
Though it’s a normal part of their life cycles, calving has been seen at an increasing rate in recent years.