100-mile-long crack in Antarctic ice shelf keeps growing

A huge crack can be seen in the Antarctic Peninsula's Larsen C ice shelf in this aerial image snapped on Nov. 10, 2016, as part of NASA's IceBridge mission. (NASA/John Sonntag)

A massive iceberg the size of Delaware is now even closer to breaking free from Antarctica, due to a widening crack in the ice shelf, scientists report.

The Larsen C Ice Shelf in Antarctica is cut through by a growing rift, which stretches nearly 109 miles (175 kilometers) long, new satellite data has revealed. Already in 2017, the rift has grown by 6.2 miles (10 km), and now only 12.4 miles (20 km) of ice are anchoring the massive iceberg to the ice shelf, according to Project MIDAS, an Antarctic research project based in the United Kingdom.

It's not a matter of if the iceberg will break off (an event known as calving), but when, scientists warn. According to MIDAS researchers, when the iceberg separates, the Larsen C Ice Shelf will lose more than 10 percent of its area — about 2,000 square miles (5,000 square km). The resulting iceberg would be one of the largest in recorded history, the scientists said.