One of the largest icebergs ever recorded — 2,500 square miles, which is about the size of Delaware — is about to break off Antarctica, according to the European Space Agency. The iceberg could speed up the break-off of other ice chunks, eventually eating away at a barrier that prevents ice from flowing to the sea.

The impending iceberg is being carved from one of the continent’s major ice shelves, called Larsen C. Scientists have been monitoring Larsen C for months now, as a deep crack has slowly extended over the course of 120 miles. Only about three miles of ice are keeping the iceberg attached to the shelf, the ESA says. No one knows when it will break off — it could be any moment — but when it does, the iceberg will likely be 620 feet thick (about the height of the Waldorf Astoria hotel in New York) and contain roughly 1 trillion tons of ice. It’ll be drifting north toward South America, and could even reach the Falkland Islands. “If so, it could pose a hazard for ships in Drake Passage," Anna Hogg from the University of Leeds, said in a statement.  

Icebergs calve off Antarctica all the time, but this one might be different. This particular break may be a sign that rising temperatures are causing the ice continent to fall apart, according to some scientists. Others believe that the cracking and melting are part of natural processes that have been going on for centuries. “We do not need to press the panic button for Larsen C,” Helen Amana Fricker, an Antarctic scientist at the Scripps Institution of Oceanography, wrote in The Guardian last month.

What’s known is that the Larsen C break-off is following similar collapses that occurred in nearby ice shelves in 1995 and 2002. These ice shelves are floating in the ocean, so when they melt or break apart, they don’t raise sea levels on their own. However, they do keep other land-based ice from flowing into the sea. Without them serving as barriers, the flow of ice from the continent could mean higher seas. West Antarctica alone might contribute 10 feet of sea level rise.

Whether Larsen C is breaking apart because of warmer temperatures or not, the planet keeps warming up. Last year was the hottest year on record — for the third in a row. That doesn’t bode well for a continent made of ice.