An iceberg larger than the city of Chicago broke off of Antartica's Pine Island Glacier Monday and is now floating freely in the Amundsen Sea.
According to Live Science, the giant iceberg measures about 278 square miles and it was spotted floating in the wild by TerraSAR-X, an Earth-observing satellite operated by the German Space Agency (DLR).
In October of 2012 NASA scientists discovered a crack in the Pina Island Glacier as they flew over to survey the ice sheet. At the time, the fracture reportedly spanned about 15 miles in length and 164 feet in width. In May 2012 satellite images showed a second fissure had formed near the top side of the first crack.
"As a result of these cracks, one giant iceberg broke away from the glacier tongue," Angelika Humbert, a glaciologist at the Alfred Wegener Institute, said in a statement.
Humbert and her team had been studying and following the two cracks for a while. She said that icebergs breaking and flowing out to sea was part of a cyclical process.
"Glaciers are constantly in motion," she said. "They have their very own flow dynamics. Their ice is exposed to permanent tensions and the calving of icebergs is still largely unresearched."
The Pine Island Glacier is the longest and fastest-changing on the West Antarctic Sheet, it last produced large icebergs in 2007 and 2008.
According to researchers, the glacier's rapid flow could have serious consequences in the ecosystem, as it "acts as a plug, holding back part of the immense West Antarctic Ice Sheet whose melting ice contributes to rising sea levels."