A day after the European Space Agency warned its demise was near, an ice bridge connecting a massive ice shelf to an island collapsed on Saturday, sending hundreds of icebergs out to sea.
The Paris-based agency on Friday published satellite images showing the bridge barely intact.
"The beginning of what appears to be the demise of the ice bridge began this week when new rifts" appeared and a large block of ice broke away, it said in a statement.
The bridge helped stabilize the Wilkins Ice Shelf and experts now fear the shelf itself will start to disintegrate over time.
The Wilkins Ice Shelf — which like the rest of Antarctic's ice sheet "was formed by thousands of years of accumulated and compacted snow" — had been stable for most of the last century before it began retreating in the 1990s, the statement said.
The shelf, which is now about the size of Connecticut, is located on the western side of the Antarctic Peninsula, which thrusts up from the continent toward the southern tip of South America.
Originally covering about 5,000 square miles, the ice shelf lost 14 percent of its mass last year alone, the statement quotes a scientist Angelika Humbert of Germany's Munster University as saying.
In two 2008 incidents, large chunks of the ice bridge fell away, shaving it down to just 985 yards across at its narrowest, the statement said.
Scientist are examining whether global warming is behind the shelf's breakup, the statement said. Average temperatures in the Antarctic Peninsula have risen by 3.8 degrees Fahrenheit over the past half century, the statement said — higher than the average global rise.
Ice shelves do not add to sea level rise since they are already in the ocean, but they do hold back ice that is grounded on Antarctica and Greenland. So as ice shelves there break up, grounded ice flows toward the seas more quickly.