The 70-mile-long rift in Antarctica’s Larsen C ice shelf that had scientists fretting last year is close to breaking away. Nothing but about 12 miles of ice is keeping the iceberg from calving—an event scientists say is “inevitable.” If or when the massive chunk does float away, it will be one of the 10 largest icebergs ever recorded.

Larsen C, Larsen C ice shelf, ice shelf, rift, ice shelf rift, Antarctica, Antarctica ice shelf, geography, climate, warming, Project Midas, NASA, environment

Scientists of United Kingdom-based Project Midas called attention to the Larsen C rift last year, but in December the rift’s growth drastically sped up. Larsen C is around 1,148 feet thick, and is one of the most major ice shelves in the north of Antarctica. The whole shelf might break up in the future should the iceberg break off soon, which at this point seems highly likely. Project Midas project leader Adrian Luckman told the BBC, “If it doesn’t go in the next few months, I’ll be amazed…it’s so close to calving that I think it’s inevitable.”

Related: 70-mile crack in Antarctic ice shelf could create Delaware-sized iceberg

The iceberg would be about 5,000 square kilometers, or around 2,000 square miles, large. The probable event follows the 1995 collapse of the Larsen A ice shelf, and the 2002 break-up of the Larsen B shelf. The rift in Larsen C has been around for decades, according to scientists, and is not a climate but a geographical event. But climate change could have hastened the Larsen C rift’s downfall, although the scientists told the BBC they don’t possess direct evidence for that hunch.

The iceberg itself probably won’t increase sea levels, but if the remaining ice shelf breaks up in the future, pushing glaciers into the ocean, there’s a high probability sea levels will rise.

Project Midas said in an article: “When it calves, the Larsen C Ice Shelf will lose more than 10 percent of its area to leave the ice front at its most retreated position ever recorded; this event will fundamentally change the landscape of the Antarctic Peninsula.”

+ Project Midas

Via the BBC

Images via NASA/John Sonntag and © MIDAS Project, A. Luckman, Swansea University