In the days leading up to President Donald Trump’s announcement on whether or not he will continue the participation of the United States in the Paris Climate Agreement, a crack in the Larsen C Ice Shelf has rapidly expanded.

From Sunday through Wednesday, the crack spread  11 miles, according to Project MIDAS, a project that monitors the Antarctic ice shelf. The crack is now just eight miles from spreading to the front of the ice, at which point the break will most likely be complete.

Read: Antarctica’s Larsen C Ice Shelf Crack Will Create One Of The Biggest Icebergs Ever When It Calves

When the ice breaks off it will create one of the largest icebergs ever recorded. Monitoring of the tear in the ice shows the tear has turned toward the outer edge of the ice where the shelf meets the water, indicating the eventual break will probably happen sooner rather than later.

The iceberg that will come off of the shelf represents about 10 percent of the entire shelf. This change will have a major impact on the Antarctic Peninsula’s landscape, especially in the northeastern area where the piece will break off. The piece of ice that breaks off will be roughly the size of Delaware. Two other icebergs have broken off of the shelf previously. Larsen B collapsed in 2002 and floated away much like the Larsen C likely will. While the Larsen B was significantly smaller than C, it floated off and broke down.

What is an ice shelf?

An ice shelf is the area of ice that surrounds the more grounded ice that makes up glaciers and ice streams. When that portion of ice breaks off, the ice it leaves behind is exposed and it speeds toward the ocean. Once it heads to the ocean it leads to sea level rise. When the piece eventually comes off it will have completed the “calving” process. “Calve” or “calving” is just a technical term for ice breaking off. When the Larsen C portion of the shelf breaks off it will likely make the rest of the shelf less stable.

Read: What Is The Paris Climate Agreement? Are Accord, Climate Change Goals Dead If Trump Withdraws US?

The Larsen C break completely cuts through the shelf vertically and is about a third of a mile deep and more than 300 feet wide, NASA said. The initial crack in the shelf was noticed in 2014 and has since made the miles of progress from one edge of the shelf to the other. The progress of recent days is startling because it happened so rapidly.

Project MIDAS has been monitoring the ice shelf since 2015. The team is made up of a number of researchers studying the effects of climate change on the ice shelf who make periodic trips to the region. It’s based at Swansea University and Aberystwyth University in the United Kingdom.