Huge Antarctic Iceberg Breaks Off

ENS, 16 October 1998

WASHINGTON, DC, October 16, 1998 (ENS)—An iceberg larger than the state of Delaware has broken off the Ronne Ice Shelf in Antarctica, the National Ice Center reported today. It is the largest iceberg to break from the Southern Hemisphere Ice Shelf since one gave way in the Ross Sea in October 1987.

Ice shelves are massive, floating sheets of snow and frozen water that encircle the Antarctic mainland.

The iceberg that broke off the Ronne Ice Shelf, named A-38, is 92 miles long by 29.9 miles wide and covers an area roughly 2750.8 square miles. It broke off the second largest ice shelf in Antarctica, located in the southern Weddell Sea.

iceberg

Satellite image of Iceberg A-38 located at 55W by 76S. (Image courtesy of the National Ice Center)

Mary Keller, a scientist at the National Ice Center in Suitland, Maryland, sighted the iceberg using satellite data.

The data are from an instrument on a satellite in the Defense Meteorological Satellite Program, the Operational Linescan System, which has a spatial resolution of .55 km (.34 miles). These satellites are operated by the National Oceanic and Atmospheric Administration (NOAA).

The National Ice Center is a tri-agency operational center represented by the U.S. Navy, NOAA and the U.S. Coast Guard. The National Ice Center's mission is to provide world-wide operational ice analyses for the armed forces of the United States and allied nations, U.S. government agencies, and the private sector.

Scientists at University College London believe that the breaking off, or calving, of icebergs is a possible indicator of global warming.

Scientists there say the mechanics of ice shelf fracturing are poorly understood. A research group at the college is planning to study ice core samples from the Ronne Ice Shelf to learn more about fracture and deformation properties.