A section of ice shelf larger than the state of Delaware broke free from Antarctica in October and is currently adrift. The massive iceberg, named A-38, broke loose from the Ronne Ice Shelf, an area in the extreme south of the Weddell Sea, on October 25.
The ice is not a threat to navigation, however, since bergs of this size typically travel slowly, run aground frequently, and stay close to land. "It will probably stay in the Weddell Sea for the next couple of years," said Ted Scambos, research scientist at the National Snow and Ice Center at the University of Colorado in Boulder. "It could eventually get out into the ocean currents if it survives long enough and move around Antarctica with the westerly drift."
The breaking off of ice shelvescalled "calving" by ice expertsis a natural process, according to Scambos, and not necessarily an indication of global warming, at least not for the area of Antarctica where A-38 broke free. However, the so-called climate limit in Antarctica has been moving southward every year, perhaps because of increasing global temperatures. Scambos explained that ice breaking off the northern tip of the Antarctic Peninsula that protrudes toward South America is not being replaced by other ice shelves.
"The typical pattern is for an ice shelf to grow and calve off large bergs every 20 or 30 years. But on parts of the peninsula the ice is retreating and not recovering," Scambos said.