The National Oceanic and Atmospheric Administration said Thursday that the berg, named A-38, broke off the Ronne Ice Shelf and is floating adjacent to the shelf. The new iceberg was sighted by Mary Keller, a scientist at the National Ice Center in Suitland, Maryland, using satellite data.
Ice shelves are massive, floating sheets of snow ice that circle Antarctica.
Some scientists believe that the breaking off, or calving, of icebergs may be an indicator of global warming. The last known iceberg of this size to calve off a Southern Hemisphere Ice Shelf was B-9 in the Ross Sea in October 1987. Iceberg names are derived from the Antarctic quadrant in which they are originally sighted. Quadrant A includes the Bellinghausen and Weddell seas and the peninsula extending toward the tip of South America. Such is the rate at which the world's oceans are rising that millions of homes near sea level could be underwater in two centuries if current predictions are correct, Wingham said.